FR3022458A1 - USE OF MANNOSYLGLYCERATE AND ITS DERIVATIVES AS AN IMMUNOSTIMULATING AGENT - Google Patents

Abstract

The present invention relates to compounds of general formula (I) wherein n represents an integer from 0 to 3, preferably n represents 0; X represents O, NR3 or S, preferably X represents O, R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5, P (O) (OR4) (OR5), P (O) (OR4) R5, SO2 (OR4) or SO2NR4R5, R2 is H, (C1-C6) alkyl, OR6, CH2OR6 or CH2NR6R7, and R3, R4, R5, R6 and R7 each independently represent one of other, H or (C1-C6) alkyl, their method of manufacture and their use as immunostimulatory agent, especially for the prevention and treatment of neoplastic and infectious pathologies.

Description

The present invention relates generally to the field of immunostimulation. In particular, the present invention relates to compounds as well as their synthesis method and an algae extract or bacteria comprising one of these compounds, useful as an immunostimulatory agent, especially for the prevention and treatment of neoplastic and infectious pathologies. Specifically, the compounds and the algae extract or bacteria of the present invention are useful as an immunostimulatory agent for vaccine prevention and treatment of different types of cancer and AIDS (Acquired Immunodeficiency Syndrome).

For many years, the role of the immune system in anti-tumor defense has remained controversial. The substantial progress made by radio- and chemotherapies has also tended to overshadow its involvement in the control of cancerous diseases for several decades. Today, it is known that an activated immune system is able to monitor, recognize and destroy malignant cells in vitro and in vivo. However, this ability to combat tumor invasion is limited by the variability, complexity and dynamics of tumor cells. Indeed, these cells are able to modulate the immune response directed against them and modify their microenvironment to escape the surveillance of the body. Cognitive advances in understanding the molecular mechanisms of immune recognition and its regulation have paved the way for new immunotherapeutic approaches. Since the late 1990s, the most common and effective are based on the use of monoclonal antibodies (Mabs). To date, six antibodies have been used in the treatment of hematological malignancies (rituximab (RTX), gemtuzumab ozagamicin, yttrium-90 Ibritumomab-Tiuxetan, alemtuzumab, tositumomab, ofatumumab). These molecules directly target and kill tumor cells with the antigens they express, more specifically, more efficiently and with fewer side effects than conventional chemotherapy. But the response rates to these treatments are very variable and resistance, due to the strategies developed by the tumor cells to escape the surveillance of the immune system, may appear. In addition, their use as monotherapy is marginal, and it is still associated with chemotherapy that these antibodies have the best therapeutic benefit.

Today, a deep knowledge of the field of fundamental immunology as well as numerous clinical data have allowed the emergence of new therapeutic strategies. These approaches are based on the use of targeting agent, not the tumor itself, but its environment, in order to activate a faulty anti-tumor immunity. These may be monoclonal antibodies targeting immune cells, cytokines or natural or chemical molecules. These molecules with high immunostimulatory potential can be used to stimulate natural immunity and potentiate the action of antitumor monoclonal antibodies through antibody-dependent cellular cytotoxicity (ADCC) or phagocytosis. Recent clinical studies have combined these immunostimulatory agents with a monoclonal antibody, RTX, for the purpose of providing therapeutic solutions to patients with resistant pathologies, generally associated with a poor prognosis (Hout et al., Cancer Metastasis Rev. 2011). Certain clinical trials presented do not make it possible to evaluate the clinical benefit of the combination of immunomodulatory drugs with rituximab versus rituximab alone (number of weak patients, no randomization, no arms with rituximab alone or in comparison). RTX alone gave 48% overall response rate for indolent NHL (non-Hodgkin's lymphoma) patients with only 6% complete response (Mc Laughlin et al., J Clin Oncol, 1998). The combination of, for example, Lenalidomide with RTX for indolent NHL patients gave 74% objective response, with 44% complete response Tuscano et al., Br J Haemato1,2014).

There remains, however, still a need for immunostimulatory compounds that can be used either in combination with other anti-tumor agents, particularly anti-tumor monoclonal antibodies, or as monotherapy in the context of neoplastic pathologies. In addition to the need for immunostimulatory compounds in anti-tumor treatment, a need is also felt in the context of anti-tumor prevention where such immunostimulatory compounds may be used alone or in combination with other preventive agents. Moreover, even if during the last ten years, scientific and medical progress have been remarkable in the prevention and treatment of infectious diseases, in particular for AIDS, there is still a need for more immunostimulant compounds and more efficient and accurate.

The role of the immune system in inflammation and carcinogenesis is highly influenced by the microenvironment. Some diseases may show unique features where the immunoregulatory processes are highly beneficial to the host, but in other cases they will be detrimental and predispose to the persistence of the pathogen and the increased risk of cancer. Immunization of healthy individuals with a hepatitis B (HB) vaccine induces a protective antibody response. 1 to 10% of the subjects do not respond to immunization and thus present a risk of infection. The production of anti-HB antibodies following vaccination or infection is dependent on helper T cells. The HLA system plays an important role in the antibody response to hepatitis B antigens. Indeed, numerous studies have shown the precise role of Th1 and Th2-derived cytokines in the immune response to hepatitis B vaccination. Analyzes have shown that adult subjects not responding to immunization have defects in the Th1, Th2 or both responses (Velu et al., Worl J Gastroentero1,2008). In addition, new approaches are needed in the prophylaxis and therapy of the HIV virus (Human Immunodeficiency Virus), which would complement and synergize with traditional strategies focused on stimulating acquired responses. The design of the HIV vaccine has hitherto been focused primarily on the induction of virus-specific antibodies or T-cell response. Numerous clinical trials have shown results with immunogens targeting antigens and T cells. A short life course has also been observed in the most recent phase III against HIV (Rerks-Ngarm et al., N Engl J Med, 2009) Many innate responders may either inhibit virus infection to increase its replication. of the virus. It is difficult to find a happy medium between a good immune response leading to the eradication of the pathogen or the tumor and a bad response creating an environment favorable to the latter. It is therefore necessary to have adjuvant compounds in a vaccine that can influence the immune system and in particular CD4 + T cells, inducing a Th1 or Th2 response.

Surprisingly, the inventors have shown that the compounds of general formula (I) exhibit immunostimulatory properties. In particular, they have demonstrated that the use of these compounds makes it possible to increase the anti-tumor activity of monocytes and neutrophils. Thus these compounds can be used for the prevention and treatment of neoplastic pathologies.

The inventors have also demonstrated that these compounds may be useful as immunostimulatory agents for vaccine prevention of infectious diseases such as AIDS.

In addition, the inventors have shown that this molecule does not exhibit toxicity with respect to tumor cells or vis-à-vis healthy cells. Thus according to a first aspect, the subject of the invention is a compound of the following formula (I): ## STR1 ## OH OH (I) or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in any proportion, including a mixture of enantiomers such as a racemic mixture, in which: n represents an integer from 0 to 3, preferably represents 0, 10 - X represents O, NR3 or S, preferably O, - R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR 5) R 4, CH 2 NR 4 R 5, P (O) (OR 4) (OR 5), P (O) (OR 4) R 5, SO 2 (OR 4) or SO 2 NR 4 R 5, - R 2 represents H, (C 1 -C 6) alkyl, OR6, CH2OR6 or CH2NR6R7, and - R3, R4, R5, R6 and R7 are each, independently of each other, H or (C1-C6) alkyl, for use as a medicament, preferentially as an immunostimulant or for the prevention and / or treatment of a pathology included in the group consisting of neoplastic pathologies and infectious diseases. In a preferred manner according to the present invention, R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5. More preferably according to the present invention, R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, and even more preferably, R1 represents CO2R4. In a preferred manner according to the present invention, R2 represents CH2OR6 or CH2NR6R7.

In a particular embodiment, the invention relates to a compound of the following formula (A): HO (A) or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions, in which: n represents an integer between 0 and 3, preferably 0, - X represents O, NR3, or S, preferentially O, - R1 represents CO2R4, COR4, CH2OR4, C ( 0) NR4R5, C (O) N (OR5) R4, CH2NR4R5, P (O) (OR4) (OR5), P (O) (OR4) R5, SO2 (OR4) or SO2NR4R5, preferentially R1 represents CO 2 R4 R2 represents H, (C1-C6) alkyl, OR6, CH2OR6 or CH2NR6R7, preferably R2 represents CH2OR6, and - R3, R4, R5, R6 and R7 each represent, independently of one another, H or (C1-6); C6) alkyl, for use as a medicament, preferentially as an immunostimulant or for the prevention and / or treatment of a pathology included in the group consisting of in neoplastic pathologies and infectious diseases. In a preferred manner according to the present invention in the compound of formula (A), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5. More preferably according to the present invention in the compound of formula (A), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, and even more preferably, R1 represents CO2R4.

In a preferred manner according to the present invention in the compound of formula (A), R2 represents CH2OR6 or CH2NR6R7. In a preferred manner according to the present invention in the compound of formula (A), n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6 or CH2NR6R7.

Preferably, carbon # 2 in formula (A) is of S configuration, i.e., the bond is in front of the plane defined by carbons 1, 2 and 3 in the present representation. above (A). Preferably, the No. 3 carbon in the formula (A) is of S configuration, that is to say the bond is in front of the plane defined by the carbons 2, 3 and 4 in the representation below. above (A). Preferably, carbon number 4 in formula (A) is of configuration R, that is to say the bond is at the rear of the plane defined by carbons 3, 4 and 5 in FIG. above (A). Preferably, the No. 5 carbon in the formula (A) is of R configuration, that is to say the bond is in front of the plane defined by the carbons 4, 5 and the oxygen of the pyranose ring in the above representation of (A). Preferably, in formula (A) and in its preferred embodiments as defined above, n is 0, X is O, R1 is CO2R4, R2 is CH2OR6, wherein R4, and R6 are each, independently of one another, H or (C1-C6) alkyl. In a particular embodiment, the invention relates to a compound of the following formula (B): (B) or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof ci in all proportions, in which: n represents an integer between 0 and 3, preferably 0, - X represents O, NR3, or S, preferentially O, 3022458 7 - R1 represents CO2R4, COR4, CH2OR4, C (0); ) NR4R5, C (O) N (OR5) R4, CH2NR4R5, P (O) (OR4) (OR5), P (O) (OR4) R5, SO2 (OR4) or SO2NR4R5, preferentially R1 represents CO2R4,, - R2 is H, (C1-C6) alkyl, OR6, CH2OR6 or CH2NR6R2, preferably R2 is CH2OR6, and 5 - R3, R4, R5, R6 and R7 are each, independently of each other, H or (C1-C6) alkyl for its use as a medicament, preferably as an immunostimulant or for the prevention and / or treatment of a pathology included in the group consisting of neoplastic pathologies and infectious pathologies.

Preferably, according to the present invention in the compound of formula (B), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5. More preferably according to the present invention in the compound of formula (B), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, and even more preferably, R1 represents CO2R4.

Preferably, according to the present invention in the compound of formula (B), R2 is CH2OR6 or CH2NR6R2. In a preferred manner according to the present invention in the compound of formula (B), n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6 or CH2NR6R2. Preferably, the carbon # 1 in the formula (B) is of S configuration, or also said a, that is to say the bond is behind the plane defined by the oxygen of the pyranose ring and carbons 1, and 2 in the above representation of (B). Preferably, the No. 3 carbon in the formula (B) is of S configuration, that is to say the bond is in front of the plane defined by the carbons 2, 3 and 4 in the representation below. above (B). Preferably, carbon number 4 in formula (B) is of configuration R, ie the bond is at the rear of the plane defined by carbons 3, 4 and 5 in the representation above (B). Preferably, the No. 5 carbon in the formula (B) is of configuration R, that is to say the bond is in front of the plane defined by the carbons 4, 5 and the oxygen of the pyranose ring in the above representation of (B).

Preferably, in formula (B) and in its preferred embodiments as defined above, n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6, wherein R4, and R6. are each independently H or (C1-C6) alkyl. In a particular embodiment, the invention relates to a compound of the following formula (C): OH (C) or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions, in which: - n represents an integer between 0 and 3, preferably 0, - X represents O, NR3, or S, preferably O, - R1 represents CO2R4, COR4, CH2OR4, C (0); ) NR4R5, C (O) N (OR5) R4, CH2NR4R5, P (O) (OR4) (OR5), P (O) (OR4) R5, SO2 (OR4) or SO2NR4R5, preferentially R1 represents CO2R4,, - R2 is H, (C1-C6) alkyl, OR6, CH2OR6 or CH2NR6R2, preferably R2 is CH2OR6, and - R3, R4, R5, R6 and R7 are each, independently of each other, H or (C1-C6) alkyl for its use as a medicament, preferably as an immunostimulant or for the prevention and / or treatment of a pathology included in the group consisting of 2 0 neoplastic pathologies and infectious pathologies. In a preferred manner according to the present invention in the compound of formula (C), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5.

More preferably according to the present invention in the compound of formula (C), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, and even more preferably, R1 represents CO2R4. In a preferred manner according to the present invention in the compound of formula (C), R 2 represents CH 2 OR 6 or CH 2 NR 6 R 7. In a preferred manner according to the present invention in the compound of formula (C), n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6 or CH2NR6R7. Preferably, the carbon # 1 in the formula (C) is of S configuration, or also said a, that is to say the bond is behind the plane defined by the oxygen of the pyranose ring and carbons 1, and 2 in the above representation of (C). Preferably, the No. 2 carbon in the formula (C) is of S configuration, that is to say the bond is in front of the plane defined by the carbons 1, 2 and 3 in the representation below. above (C). Preferably, the No. 4 carbon in the formula (C) is of R configuration, that is to say the bond is behind the plane defined by the carbons 3, 4 and 5 in the representation below. above (C).

Preferably, the No. 5 carbon in the formula (C) is of R configuration, that is to say the bond is in front of the plane defined by the carbons 4, 5 and the oxygen of the cycle pyranosis in the above representation of (C). Preferably, in the formula (C) and in its preferred embodiments as defined above, n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6, in which R4, and R6 represent each, independently of one another, H or (C1-C6) alkyl. In a particular embodiment, the invention relates to a compound of the following formula (D): HO-OH (D) or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions, wherein: n represents an integer between 0 and 3, preferably 0, - X represents O, NR3, or S, preferably O, - R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5, P (O) (OR4) (OR5), P (O) (OR4) R5, SO2 (OR4) or SO2NR4R5, preferentially R1 represents CO2R4 R2 represents H, (C1-C6) alkyl, OR6, CH2OR6 or CH2NR6R7, preferably R2 represents CH2OR6, and - R3, R4, R5, R6 and R7 each represent, independently of one another, H or (C1-6); C6) alkyl, for its use as a medicament, preferably as an immunostimulant or for the prevention and / or treatment of a pathology included in the group consi stant in neoplastic pathologies and infectious pathologies. In a preferred manner according to the present invention in the compound of formula (D), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5. More preferably according to the present invention in the compound of formula (D), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, and even more preferably, R1 represents CO2R4. In a preferred manner according to the present invention in the compound of formula (D), R2 represents CH2OR6 or CH2NR6R7. In a preferred manner according to the present invention in the compound of formula (D), n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6 or CH2NR6R7. Preferably, the carbon # 1 in the formula (D) is of S configuration, or also said a, that is to say the bond is behind the plane defined by the oxygen of the pyranose ring and carbons 1, and 2 in the above representation of (D). Preferably, the carbon number 2 in the formula (D) is of S configuration, that is to say the bond is in front of the plane defined by the carbons 1, 2 and 3 in the representation below. above (D).

Preferably, the carbon number 3 in the formula (D) is of S configuration, that is to say the bond is in front of the plane defined by the carbon atoms 2, 3 and 4 in the representation above (D). Preferably, the No. 5 carbon in the formula (D) is of R configuration, that is to say the bond is in front of the plane defined by the carbons 4, 5 and the oxygen of the pyranose ring. in the above representation of (D). Preferably, in the formula (D) and in its preferred embodiments as defined above, n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6, in which R4 and R6 each represent , independently of each other, H or (C1-C6) alkyl. In a particular embodiment, the invention relates to a compound of the following formula (E): (E) or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof ci in all proportions, in which: n represents an integer between 0 and 3, preferably 0, - X represents O, NR3, or S, preferentially O, - R1 represents CO2R4, COR4, CH2OR4, C (O); NR4R5, C (O) N (OR5) R4, CH2NR4R5, P (O) (OR4) (OR5), P (O) (OR4) R5, 502 (OR4) or SO2NR4R5, preferably R1 represents CO2R4, - R2 represents H, (C1-C6) alkyl, OR6, CH2OR6 or CH2NR6R2, preferably R2 is CH2OR6, and - R3, R4, R5, R6 and R7 are each, independently of each other, H or (C1-C6) alkyl, 3022458 12 for its use as a medicament, preferably as an immunostimulant or for the prevention and / or treatment of a pathology included in the group consisting of in neoplastic pathologies and infectious pathologies. In a preferred manner according to the present invention in the compound of formula (E), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, CH2NR4R5. More preferably according to the present invention in the compound of formula (E), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4, and even more preferably, R1 represents CO2R4. In a preferred manner according to the present invention in the compound of formula (E), R2 represents CH2OR6 or CH2NR6R7. In a preferred manner according to the present invention in the compound of formula (E), n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6 or CH2NR6R7. Preferably, the No. 1 carbon in the formula (E) is of S configuration, or also said a, that is to say the bond is behind the plane defined by the oxygen of the pyranose ring and carbons 1, and 2 in the above representation of (E). Preferably, the carbon number 2 in the formula (E) is of S configuration, that is to say the bond is in front of the plane defined by the carbons 1, 2 and 3 in the representation below. above (E). Preferably, the No. 3 carbon in the formula (E) is of S configuration, that is to say the bond is in front of the plane defined by the carbons 2, 3 and 4 in the representation below. above (E).

Preferably, carbon number 4 in formula (E) is of configuration R, that is to say the bond is at the rear of the plane defined by carbons 3, 4 and 5 in FIG. above (E). Preferably, in the formula (E) and in its preferred embodiments as defined above, n is 0, X represents O, R1 represents CO2R4, R2 represents CH2OR6, in which R4, and R6 represent each, independently of one another, H or (C1-C6) alkyl.

In particular, said compound has the following formula (I-1): ## STR1 ## According to a particular embodiment, said compound meets with the following formula (1-1a): HO OH (1-1a) According to a particular embodiment, in the formulas (I), (1-1) and (1-1a), n represents 0. According to one embodiment, particular embodiment, in formulas (I), (1-1) and (1-1a), X represents O.

According to a particular embodiment, in formulas (I), (1-1) and (1-1a), R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4. or CH2NR4R5. According to a particular embodiment, in the formulas (I), (1-1) and (1-1a), R2 represents CH2OR6 or CH2NR6R2. According to a particular embodiment, in formulas (I), (1-1) and (1-1a): n represents 0, - X represents 0, 3022458 14 - R1 represents CO2R4, COR4, CH2OR4, C ( 0) NR4R5, C (O) N (OR5) R4 or CH2NR4R5, - R2 represents CH2OR6 or CH2NR6R7, and according to a particular embodiment, in the formulas (I), (1-1) and (1-1a), R1 represents CO2R4, C (O) NR4R5 or C (O) N (OR5) R4, in particular CO2R4.

According to a particular embodiment, in formulas (I), (1-1) and (1-1a), R2 represents CH2OR6. The term "C1-C6 alkyl" in the context of the present invention is understood to mean a linear or branched saturated hydrocarbon-based chain containing from 1 to 6 carbon atoms, for example a methyl, ethyl, isopropyl or tert-butyl group, n-pentyl, etc.

The term "pharmaceutically acceptable salt" in the context of the present invention, any salt suitable for pharmaceutical use. As examples of pharmaceutically acceptable salts, mention may be made of benzene sulphonate, hydrobromide, hydrochloride, citrate, ethanesulphonate, fumarate, gluconate, iodate, isethionate, maleate, methanesulphonate, methylene-bis-b-oxynaphthoate, nitrate, oxalate, pamoate, phosphate, salicylate, succinate, sulfate, tartrate, theophyllineaceate and p-toluenesulfate. In particular, said pharmaceutically acceptable salt may be a base addition salt, especially an alkali metal salt, such as a sodium or potassium salt. Thus, said compound may be in the form of a base addition salt, in particular in the form of an alkali metal salt, for example sodium or potassium salt.

More particularly, said compound is 2-OaD-mannopyranosyl-D-glycerate, also known as digenase, the chemical structure of which is: ## STR2 ## 2-OaD-mannopyranosyl- D-glycerate (digeneas) was isolated for the first time from the red alga Polysiphonia fastigiata (Colin et al., Weekly Proceedings of Science Academy Sessions, 1939) and its molecular structure was established by the methylation technique 2-OaD-mannopyranosyl-D-glycerate is a compound formed by a mannose sugar bound to a glyceride at a (1 → 2) This compound is negatively charged at neutral pH and has a mass 268 g.mo1-1 molecular structure Its chemical structure was assigned on the basis of nuclear magnetic resonance spectroscopy (NMR) and mass spectroscopy (MS) by Ascensio et al (Ascencio et al., Carbohydrate Res, 2006).

The 2-OaD-mannopyranosyl-D-glycerate (digeneas) can be obtained by chemical synthesis or from extracts of algae comprising this compound such as algae belonging to the order of ceramials or bangials according to methods of the invention. extraction and purification well known to those skilled in the art, such as those described in the "examples" part of the present application.

2-O-α-D-mannopyranosyl-D-glycerate can also be obtained from thermophilic and hyperthermophilic bacteria such as Thermus thermophilus and Rhodothermus marinus. In this case, the term used for 2-O-α-D-mannopyranosyl-D-glycerate is mannosylglycerate. In the context of the present invention the term "mannosylglycerate" is also used to designate 2-O-α-D-mannopyranosyl-D-glycerate obtained by standard synthetic chemistry techniques. Among these conventional techniques of synthetic chemistry, a particular method (a1) has been developed in the context of the present invention. Thus, an object according to the present patent application relates to the method of synthesis (a1) of compounds according to any one of formulas (I), (A), (B), (C), (D), (E ), (1-1) and (1-1a), or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in any proportion, characterized in that this process comprises the steps of: (1) forming a hexopyranose dimer, wherein the two hexopyranoses are connected to one another via an appropriately substituted glycolic linkage and, on the other hand, said hexopyranoses are suitably protected the case optionally and preferably identical, (2) cleavage and oxidation of the CC bond of the glycolic unit, and (3) recovery of the compounds of formulas (I), (A), (B), (C), (D), (E) ), (1-1) and (1-1a), after possible deprotection, salt formation or subsequent functionalization, if appropriate.

Preferably, the method (a1) above comprises at least one purification step. In the context of the present invention, it is understood that in step (2) the expression "cut and oxidation of the bond CC of the glycolic unit" allows the cutting and then the oxidation of the bond CC of the glycolic unit. connecting the two hexopyranoses by the insertion of two oxygen atoms to give two carbonyl groups. Thus, in the step (2) of oxidation of the glycolic bond, the typical oxidation reactions of this bond can be applied such as the so-called "Criegee", "Rigby" or "Malaprade" reaction. optionally followed by further oxidation to obtain the corresponding carboxylic acid. Thus, all the chemical agents that can be used in the reactions of "Criegee", "Rigby" or "Malaprade" are likely to produce the desired effect according to the molecule to be split. Examples of oxidizing agents are Pb (OAc) 4, NaBiO4 / H3PO4, H104, TEMPO (2,2,6,6-tetramethylpiridinyloxide), AZADO (2-azaadamantane N-oxyl), 1-Me- AZADO (1-methyl-2-azaamandate N-oxyl). It is possible that the oxidizing agents are used in step (2) in combination with a co-oxidant such as BAIB (bis-acetoxyiodobenzene) according to the method described by Piancatelli G et al. (Piancatelli et al., 2006) or with PIFA (phenyliodine bis trifluoroacetate) according to Dohi T et al. (Dohi et al., Green Chem, 2012) or Shibuya M et al. (Shibuya et al., 2006). In particular, the combination of hypervalent iodine (III) and TEMPO reagents (or derivatives thereof) is specifically known to promote efficient and chemoselective oxidation of alcohol functions to access highly functionalized carbonyl compounds. Advantageously, the hydroxyl groups which it is desired to preserve in the molecule in process (a1) are protected by acetyl groups, which are removed in a conventional manner at the end of synthesis, for example by trans-esterification or trans-amidation, such as by the use of hydroxyammonium in the presence of methanol.

Obtaining the hexopyranose dimer according to process (a1) above can be done by a strategy for protecting / deprotecting the glycol function via the corresponding isopropylidene derivative. The formation of the hexopyranose dimer according to process (a1) above can be carried out by the use of a suitably protected sac, preferably comprising an isopropylidene protected glycol function. Preferably, the suitably protected dye allowing dimerization is a suitably protected sugar alcohol, such as suitably protected mannitol. More preferably, suitably protected mannitol is 1,6-di-O-acetyl-3,4-diisopropylidene-D-mannitol. The hexopyranoses that can be used in process (a1) above are those conventionally known to those skilled in the art, and in particular allose, altrose, glucose, mannose, gulose, idose, galactose and / or talose in their D or L forms, preferably D. Thus, a particular embodiment of process (a1) relates to a synthesis process (a2) of compounds according to any one of formula (I) , (A), (B), (C), (D), (E), (1-1) and (1-1a), characterized in that this process comprises the steps of: (1 ') a selective coupling of the OH of the anomeric carbon of a hexopyranose with a reactive function such as an activated hydroxyl of a dye suitably protected at least by an isopropylidene group covering a glycol function, (2 ') a selective deprotection of the hydroxyl groups covered by isopropylidene, (3 ') an oxidative cleavage of the glycol obtained after step (2'), (4 ') a final deprotection step, and (5') recovering the product of formula (I), (A), (B), (C), (D), (E), (1-1) and (1-1a), or a pharmaceutically acceptable salt thereof ci, or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions. Preferentially, the process (a2) above comprises at least one purification step.

Advantageously, the hydroxyl groups which it is desired to preserve in the molecule in process (a2) are protected by acetyl groups, which are removed in a conventional manner at the end of synthesis, for example by trans-esterification or trans-amidification. such as by the use of hydroxyammonium in the presence of methanol. Obtaining the hexopyranose dimer according to process (a2) above can be done by a strategy for protecting / deprotecting the glycol function via the corresponding isopropylidene derivative. The formation of the hexopyranose dimer according to process (a2) above can be carried out by the use of a suitably protected sac, preferably comprising an isopropylidene protected glycol function. Preferentially, suitably protected dimer allowing dimerization is a suitably protected sugar alcohol, such as suitably protected mannitol. More preferably, the suitably protected mannitol is 1,6-di-O-acetyl-3,4-diisopropylidene-D-mannitol. The hexopyranoses that can be used in process (a2) above are those conventionally known to those skilled in the art, and in particular allose, altrose, glucose, mannose, gulose, idose, galactose and / or talose in their D or L forms, preferentially D in their pyranose form. Preferably, the hexopyranose dimer is a mannopyranosyl dimer, particularly in its D form. In the above process (a2), in step (1 '), suitably protected dose is 1.6-di-O-acetyl-3,4-diisopropylidene-mannitol, preferably of D-form, is advantageous. An object according to the present patent application relates to the product that can be obtained by any of the processes (a1) or (a2) above, as well as their particular embodiments. The present invention also relates to a compound according to the invention as defined above, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions, for its use as an immunostimulatory drug. The term "immunostimulatory drug" in the sense of the present invention, any drug capable of stimulating the function of cells involved in normal immune responses. This stimulation can result in the increase of pro-inflammatory cytokines and the potentiation of the cytotoxic activity of Natural Killer (NK) cells and neutrophils. By way of example, in order to determine the efficacy of an immunostimulatory drug, the level of a pro-inflammatory cytokine, such as interferon gamma (IFN-γ), can be determined in a biological sample of a subject treated with the immunostimulatory drug as compared to an untreated subject. Immunostimulation may result in statistically significant (LLC-B) difference in the level of this pro-inflammatory cytokine in a biological sample of the subject to whom the immunostimulatory drug has been administered. In addition, the compounds of the present invention can induce the release of other cytokines such as Interleukin 12 (IL-12). The main role of this cytokine is to potentiate the cytotoxic activity and to participate in the regulation of the proliferation of T lymphocytes and NK cells. It induces the production of IFN-γ and promotes the differentiation of Th-1-like helper cells and inhibits the differentiation of Th-2-type T cells. It is produced by phagocytic cells, dendritic cells, B cells and neutrophils. Administration of IL-12 in vivo stimulates the activity of NK and cytotoxic T cells (CTL), with induction of IFN-γ production, and differentiation of Th-1 cells. Thus, as an adjuvant during immunization, IL-12 promotes differentiation of Th-1 type cells and inhibits differentiation of IL-4 producing cells. Administration of IL-12 to tumor-bearing mice may prolong their survival by significantly inhibiting tumor progression (Lasek et al., Cancer Immunol Immunother, 2014). The present invention also relates to a compound according to the invention as defined above, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions, for its use as a medicament for the prevention and / or treatment of a pathology included in the group consisting of neoplastic pathologies and infectious diseases. For the purposes of the present invention, the term "neoplastic pathology" is understood to mean any pathology in which cells exhibit abnormal growth such as, for example, uncontrolled cell proliferation. In particular, the neoplastic pathologies can be included in the group consisting of: lymphomas, leukemias, breast cancers, uterine cancers, colon cancers, prostate cancers, bladder cancers, carcinomas, bronchial cancers, oral-rhino-laryngeal cancers, stomach cancers and brain tumors.

For the purpose of the present invention, the term "infectious pathology" means any pathology caused by an infectious agent such as a virus, a bacterium or a fungus. In particular, the infectious diseases may be included in the group consisting of pathologies related to VI H. The present invention also relates to a compound according to the invention as defined above, or a pharmaceutically acceptable salt thereof. or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions, for use as a medicament for the prevention of a pathology included in the group consisting of neoplastic pathologies by vaccine amplification. The present invention also relates to a compound according to the invention as defined above, or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof, or a mixture of stereoisomers thereof in all proportions, for use as a medicament for the prevention and / or treatment of an HIV-related infectious disease.

For the purposes of the present invention, the term "mixture of enantiomers" is intended to mean a composition which comprises at least one pair of enantiomers in all proportions. More particularly, the term "racemic mixture" means a mixture of two enantiomers in which the mass ratio between these two enantiomers is 1: 1, ± 10% by weight of each enantiomer. Advantageously, the mixture of the two enantiomers is enriched, that is to say that the ratio of the two enantiomers is different from 1: 1 ± 10% by weight of each enantiomer. Preferably, one of the two enantiomers is present in the mixture in a mass ratio greater than 60% with respect to its enantiomeric homologue. More preferably, one of the two enantiomers is present in the mixture in a mass ratio greater than 80% with respect to its enantiomeric homologue. Even more preferably, one of the two enantiomers is present in the mixture in a mass ratio greater than 90% with respect to its enantiomeric homologue. Most preferably, one of the two enantiomers is present in the mixture in a mass ratio greater than 95% vis-à-vis its enantiomeric counterpart. The present invention also relates to an extract of at least one alga belonging to the order of ceramials or bangials for its use as a medicament, said extract comprising 2-OaD-mannopyranosyl-D-glycerate (digenase) . In particular, said extract comprises a content of 2-OaD-mannopyranosyl-D-glycerate (digenease) in the range of 0.1% to 2.0%, preferably 0.5% to 1.5% by weight. relative to the total weight of the extract, expressed as dry extract. The maximum concentration of digenase content is related to the seasonal variation of the seaweed used. Said extract of at least one alga belonging to the order of ceramiales (for example, the genera Ceramium, Polysiphonia and Laurencia) or bangials (genus Bangia) comprising 2-Oa-Dmannopyranosyl-D-glycerate (digeneas) can be obtained by any techniques well known to those skilled in the art, such as by at least one extraction step.

In particular, these extracts may be aqueous extracts, ethanolic extracts or aqueous hydroalcoholic extracts of azeotropic type (70/30) or more. Classically here, as in herbal medicine, polar solvents are widely used since the digenase molecule is carbohydrate type. The polar solvents that can be used for the extraction can be of mineral or organic nature. For example solvents that can be used are selected from the list consisting of water, any type of alcohol, such as ethanol, methanol, propanol, isopropanol, or butanol; aromatic solvents such as pyridine, toluene, chlorobenzene or else xylene, or carbonyl solvents such as acetone, dimethyl formamide or methyl pyrrolidone, esters such as ethyl acetate, sulfoxides such as dimethylsulfoxide, nitriles such as acetonitrile, halogenated solvents, such as dicholoromethane, dichloroethane, chloroform, carbon tetrachloride, chlorobenzene, or ether-oxide solvents such as diethylene glycol, tetrahydrofuran, diethyl ether. Preferably, the extraction solvent is a biological solvent, that is to say, naturally encountered such as ethanol or acetone. In addition, the solvent may be chosen from alcohol type solvents, preferably ethanol. The extracts may also be in the form of lyophilized powder.

Generally, these extractions are done from the whole plant. The digenase molecule can also be co-extracted in a minority amount with the floridoside molecule, isofloridoside belonging to the same class of natural molecules (Karsten et al., Phycologia, 2007).) It is thus possible to extract mixtures of the three natural molecules in the order of gigartinales and in the order of the gracilariales.

It is possible to carry out several successive extractions until exhaustion of the material to be extracted by the solvent in question. The extraction time varies depending on the solvent, the temperature and possibly the pressure used, to result in the total exhaustion of extraction of the material. In practice, this duration will advantageously be limited to less than 2 hours for profitable industrial exploitation. Prior to the extraction step, said algae can be washed, ground, cut, crushed and / or dried. The term "dry extract" in the sense of the present invention, the dry matter which remains after desiccation of an extract, for example in an oven at 120 ° C for 2 hours.

The present invention also relates to an extract of at least one algae according to the invention for its use as an immunostimulatory drug. The subject of the present invention is also an extract of at least one algae according to the invention for its use as a medicament for the prevention and / or treatment of a pathology included in the group consisting of neoplastic pathologies and Infectious diseases.

The subject of the present invention is also an extract of at least one alga according to the invention for its use as a medicament for the prevention by vaccine amplification of a pathology included in the group consisting of neoplastic pathologies. The present invention also relates to an extract of at least one algae according to the invention, for its use as a medicament for the prevention and / or treatment of an HIV-related infectious disease. The present invention also relates to a pharmaceutical or nutraceutical composition comprising: at least one component selected from the group consisting of: a compound according to the invention as defined above, a pharmaceutically acceptable salt thereof, a stereoisomer thereof, a mixture of stereoisomers thereof in all proportions, and an extract of at least one alga according to the invention as defined above; and a pharmaceutically or nutraceutically acceptable vehicle. For the purpose of the present invention, the term "nutraceutical composition" is intended to mean a composition relating to a product made from foods (in the case of the present invention it is the extract of the algae or algae). whole) and marketed as a tablet, powder or potion with a beneficial physiological effect against chronic diseases. For the purposes of the present invention, the term "pharmaceutically acceptable carrier" means any material which is suitable for use in a pharmaceutical product. By way of example of a pharmaceutically acceptable vehicle, mention may be made of lactose, optionally modified starch, cellulose, hydroxypropylmethylcellulose, mannitol, sorbitol, xylitol, dextrose, calcium sulphate and phosphate. calcium, calcium lactate, dextrates, inositol, calcium carbonate, glycine, bentonite and mixtures thereof. By "nutraceutically acceptable carrier" in the sense of the present invention is meant any material which is suitable for use in a nutraceutical product. As a nutraceutically acceptable carrier, there may be mentioned dicalcium phosphate, calcium alginate, magnesium carbonate, talc, magnesium stearate, silicon dioxide, calcium chloride, or the like. The composition according to the invention may comprise from 0.1% to 30% by weight of at least one of the compounds of the invention relative to the total weight of the composition.

In particular, the composition according to the invention may comprise from 0.5% to 20%, more particularly from 5% to 20% or from 0.5% to 5%, in particular from 0.5% to 1.5%. at least one of the compounds of the invention, by weight relative to the total weight of the composition. In a particular embodiment, the composition according to the invention is a pharmaceutical composition which may comprise from 0.1% to 30%, in particular from 0.5% to 20%, more particularly from 5% to 20%, or 0.5% to 5%, in particular from 0 to 1.5% of at least one of the compounds of the invention, by weight relative to the total weight of the composition. Preferably, the pharmaceutical composition according to the invention comprises from 5% to 20% or from 10% to 15% of at least one of the compounds of the invention, by weight relative to the total weight of the composition. In another particular embodiment, the composition according to the invention is a nutraceutical composition which can comprise from 0.1% to 30%, in particular from 0.5% to 20%, more particularly from 5% to 20%, or 0.5% to 5%, in particular 0.5 to 1.5% of at least one of the compounds of the invention, by weight relative to the total weight of the composition.

Preferably, the nutraceutical composition according to the invention comprises from 0.5% to 5%, more preferably from 1% to 1.5%, of at least one of the compounds of the invention, by weight relative to the weight total of the composition. The composition according to the invention may comprise a content of pharmaceutically or nutraceutically acceptable vehicle ranging from 5 to 99%, in particular from 10 to 99% and very particularly from 20 to 75% by weight relative to the total weight of the composition. In particular, said composition according to the invention may be a pharmaceutical composition further comprising at least one other anti-tumor agent. The term "anti-tumor agent" according to the present invention, any compound having an anti-tumor effect. The antitumor agent may have an effect of preventing or inhibiting the formation or growth of tumors or tumor cells. This effect can be a pro-apoptotic, anti-proliferative, cytostatic or cytotoxic effect. Examples of antitumor agents include anti-metabolites, enzyme inhibitors, cytokines and antitumor antibodies. In particular, said other anti-tumor agent may be an anti-tumor antibody.

The term "anti-tumor antibody" according to the present invention means any antibody having an anti-tumor effect. In particular, said anti-tumor antibody can be included in the group consisting of rituximab, trastuzumab, cetuximab, bevacizumab, gemtuzumab ozagamicin, yttrium-90 Ibritumomab-Tiuxetan, alemtuzumab, tositumomab and ofatumumab.

The composition according to the invention may comprise 2-O-α-D-mannopyranosyl-D-glycerate and said other anti-tumor agent in a molar ratio ranging from 10/1 to 1/10. In particular, when said other anti-tumor agent is an anti-tumor antibody, the composition according to the invention may comprise 2-OaD-mannopyranosyl-D-glycerate and said anti-tumor antibody in a concentration ratio ranging from 4: 1 to 13/1, in particular 5/1 to 10/1 and preferably 10 to 10/1. In particular, said composition according to the invention may be a pharmaceutical composition comprising, in addition, at least one other immunostimulatory agent. For the purposes of the present invention, the term "immunostimulatory agent" means any agent capable of stimulating the function of the cells involved in normal immune responses. In particular, said other immunostimulatory agent may be included in the group consisting of cytokines, polysaccharides and mineral adjuvants. The composition according to the invention may comprise 2-O-α-D-mannopyranosyl-D-glycerate and said other immunostimulatory agent in a molar ratio ranging from 10/1 to 1/10. In particular, said composition according to the invention may be a pharmaceutical composition comprising, in addition, at least one other anti-infective agent. The term "anti-infective agent" in the sense of the present invention, any agent for inhibiting growth and / or eliminate an infectious agent. In particular, said other anti-infective agent may be included in the group consisting of natural anti-infectives such as grapefruit seed extract and bramble extract.

The composition according to the invention may comprise 2-O-α-D-mannopyranosyl-D-glycerate and said other anti-infective agent in a molar ratio ranging from 10/1 to 1/10. In particular, said composition according to the invention may be a nutraceutical composition further comprising vitamins, antioxidants, preservatives and foods such as cereals, mushrooms (for example, shiitake).

The present invention also relates to a pharmaceutical composition according to the invention for use as a medicament for the prevention and / or treatment of a pathology included in the group consisting of neoplastic pathologies and infectious diseases.

The present invention also relates to the use of at least one pharmaceutical composition according to the invention as defined above or at least one component selected from the group consisting of: a compound according to the invention as defined above, a pharmaceutically acceptable salt thereof, a stereoisomer thereof, a mixture of stereoisomers thereof in all proportions, and an extract of at least one algae according to the invention as defined above; for the preparation of a medicament for the prevention and / or treatment of a pathology included in the group consisting of neoplastic pathologies and infectious diseases.

The present invention also relates to a method for preventing and / or treating a pathology included in the group consisting of neoplastic pathologies and infectious diseases, said method comprising a step of administering to a patient a therapeutically effective dose of at least one pharmaceutical composition according to the invention as defined above or at least one component selected from the group consisting of: a compound according to the invention as defined above, a salt pharmaceutically acceptable thereof, a stereoisomer thereof, a mixture of stereoisomers thereof in all proportions, and an extract of at least one algae according to the invention as defined above. The present invention also relates to a product comprising: at least one component selected from the group consisting of: a compound according to the invention as defined above, a pharmaceutically acceptable salt thereof, a stereoisomer of that a mixture of stereoisomers thereof in all proportions, and an extract of at least one alga according to the invention as defined above; and - at least one other anti-tumor agent; As a combination product for simultaneous, separate or spread use over time for the prevention and / or treatment of a neoplastic pathology. In particular, said neoplastic pathology is included in the group consisting of lymphomas, leukemias, breast cancers, uterine cancers, colon cancers, prostate cancers, bladder cancers, carcinomas, bronchial cancers, oro-rhino-laryngeal cancers, cancers of the stomach and brain tumors. In particular, said other anti-tumor agent is an anti-tumor antibody, very particularly included in the group consisting of rituximab, trastuzumab, cetuximab, bevacizumab, gemtuzumab ozagamicin, yttrium-90 Ibritumomab-Tiuxetan, alemtuzumab, tositumomab and ofatumumab. The subject of the present invention is also a product comprising: at least one component selected from the group consisting of: a compound according to the invention as defined above, a pharmaceutically acceptable salt thereof, a stereoisomer thereof ci, a mixture of stereoisomers thereof in all proportions, and an extract of at least one algae according to the invention as defined above; and - at least one other anti-infective agent; as a combination product for simultaneous, separate or spread use over time for the prevention and / or treatment of an infectious disease. The pharmaceutical composition, the drugs and combination products according to the invention are administrable by different routes. As examples of administration routes that can be used for the pharmaceutical composition, the drugs and combination products according to the invention include the oral route, the rectal route, the cutaneous route, the pulmonary route, the nasal route, the sublingual route, parenteral route including intradermal route, subcutaneous route, intramuscular route, intravenous route, intra-arterial route, intraspinal route, intra-articular route, intra-pleural route and route. intraperitoneal. The pharmaceutical composition and the medicaments according to the invention can be administered in one or more times or in continuous release. Preferably, the pharmaceutical composition or the medicaments according to the invention are administered in continuous release, such as in the form of an infusion or by means of a pharmaceutical form, such as a capsule or an optionally coated tablet. , extended and / or delayed release.

The pharmaceutical composition, the medicaments and combination products according to the invention may be in various forms, in particular in a form chosen from the group consisting of injectable solutions, tablets, capsules, dragees, syrups, suspensions, solutions, powders, granules, emulsions, microspheres, especially injectable solutions, such as infusion solutions are preferred. In addition, sustained release dosage forms such as capsules, or tablets optionally coated for sustained release will be preferred. The nutraceutical composition according to the invention is administrable especially orally, for example, in the form of breakable tablets or not, film-coated or not, granules, capsules, capsules, or in the form of free powders packaged preferably in sachets. units, or compressed powder. These different forms can be obtained by techniques well known to those skilled in the art. Other advantages and characteristics of the invention will become apparent with reference to the examples which follow and which refer to the following figures: FIG. 1: Diagram representing the cytotoxicity of the following compounds: digeneaside, floridoside (F) and isofloridoside ( I), on Daudi cells. Figure 2: Diagrams showing the cytotoxicity of Firoin® on patient cells with B-CLL (P024-5 Figure 1a, P018-6 Figure 2b); Figure 3: Diagram showing the kinetics of production of IFN-γ by PBMCs treated with LPS, digénéaside or Floridoside. Figure 4: Western blot representing the expression of STAT3 and STAT3 phosphorylated proteins (pY705) on PBMCs (Time 4H and 24H Figure 4a, time 48H and 72H Figure 4b). Figure 5: Graph showing the action of digenase with RTX on different donors. Figure 6: Graph showing the action of digenase (Figure 6a) and Firoin® (Figure 6b) with RTX. Figure 7: Graph showing the results of the digenase assay (Figure 7a) and Firoin® (Figure 7b) with the HLA-DR antibody.

Figure 8: Graph showing the impact of Firoin® on the monocyte population after 5 days. Figure 9: Diagram showing the effect of digenase on phagocytosis of FITC bacteria.

Figure 10: Diagram showing the kinetics of phagocytosis of dextran-FITC by neutrophils after 24H (Fig. 10a) and 48H (Fig. 10b) incubation in the presence of Firoin®. Figure 11: Diagram showing the survival curve of five groups of immunodeficient SOPF / NOD.Cg-Prkdc Scid mice after inoculation of tumor cells followed by different treatments. Figure 12: Diagram showing the survival curve of immuno-competent SOPF / C57BL / 6JRJ mice after inoculation of the tumor cells and injection of RTX and digeneaside (2mg and 4mg) alone or in combination; Figure 13: Histological sections showing expression of CD20 by immunohistochemistry in the lungs of SOPF / C57BL / 6JRJ mice died in the first 40 days; Figure 14: Histological sections showing the expression of CD20 by immunohistochemistry in various organs of SOPF / C57BL / 6JRJ mice transfused with a solution of digénéaside (2 mg or 4 mg) and euthanized at J187. Figure 15: Histological sections showing the expression of CD20 by immunohistochemistry in different organs of SOPF / C57BL / 6JRJ mice transfused with a solution of RTX, RTX + digeneaside (2mg or 4mg) and euthanized at J187.

EXAMPLES EXAMPLES OF SYNTHESIS AND EXTRACTION 1. Chemical Synthesis The description of the chemical synthesis of mannosylglycerate is shown in Scheme 1.

Reagents: Trichloroacetonitrile (CCI3CN), 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), trimethylsilyl trifluoromethanesulfonate (TMSOTf), trifluoroacetic acid (TFA), 2,2, 6,6-Tetramethyl-piperidin-1-oxide (TEMPO), (Diacetoxyiodo) -benzene (Phl (OAc) 2). Abbreviations: Ambient temperature (Ta), molecular sieve (TM) 3,4-O-lsopropylidene-D-mannitol 1 5 4 2x AcO AcAc0 Ac0 0 Cr O NHa NH4OH / CH3OH OH 36h at ta, 86% CH2Cl2 TMSOTf TM ( 4A °) 2h30 -15 ° C at 0 ° C 58% OAc OAc O AcO AcO AcO OAc Ac0 0 O AcO AcO AcO OAcAc0 Ac Ac0 AcO O AcO TFA / H20 AcO OAc OAc - HO OH 30 min at ta., 64% O. TEMPO / Phl (OAc) 2 CH 2 Cl 2 / H 2 O 1: 1 1 hr at t., 95% 7 AcO morph AcO neicH 2 Cl 2 Ac O 1h reflux OAc Quant. pentaacetyl mannose A OAc AcO CCI3CN / DBU AcO OH CH2Cl2, 5.302 Tg, 77% AcO OAc Acc0 -0 0 A OH AcOEt / K2CO3 AcO 45 min reflux, 40% OAc OH HO 3022458 2,3,4, 6-Tetra-O-acetyl-D-mannose 2: OH 20 g (51.24 mmol) of peracetylated D-mannose (Mallesha et al., J Chem Res, 2011) are dissolved in 80 mL of anhydrous CH2Cl2 under argon. 18 ml (205 mmol) of morpholine are added and the reaction mixture is refluxed for 1 hour. The reaction mixture, brought to room temperature, is neutralized with 1N HCl solution (200 mL) and then washed with 2x100 mL of water. The organic phase is then dried over MgSO4, filtered and concentrated in vacuo to yield compound 2 (16.38 g) as an oil in 92% yield. Rf = 0.36 [AcOEt / cyclohexane (5: 5)] MS, El + m / z: 371 [M + Na] 2,3,4,6-tetra-O-acetyl-α-D-mannopyranose trichloroacetimidate 3: 16.38 g (47.03 mmol) of compound 2 are dissolved, under an inert atmosphere, in 130 ml of distilled CH 2 Cl 2. 47 mL (470.3 mmol) of trichloroacetonitrile and 2.11 mL (14.1 mmol) of DBU (1,8-diazabicyclo [5.4.0] undec-7-ene) are added at 0 ° C. The reaction medium is stirred for 5 hours at ambient temperature and then evaporated under reduced pressure. The residue obtained is purified by chromatography on silica gel (cyclohexane / AcOEt, 6: 4 + 1% Et3N) to yield product 3 with a yield of 77%. 1,6-Di-O-acetyl-3,4-Di-O-isopropylidene-D-mannitol 1: OH HO 2 4C-6-OAc d / 3,4-Di-O-isopropylidene D-mannitol (3.65 g, 16.42 mmol) and potassium carbonate (3.4 g, 24.63 mmol) are suspended in 160 mL of ethyl acetate. After stirring for 1 h at 90 ° C., the reaction mixture is sintered and rinsed several times with dichloromethane. Purification by silica gel chromatography (CH2Cl2 / Et2O, 7: 3) yielded diacetylated mannitol 1 (2.03 g, 6.63 mmol, 40%) as a colorless oil. MS, EI + m / z: 329.2 [M + Na] + 1H NMR (600 MHz, CDCl3, 298 K): 6 ppm 4.45 (d, 2Hrt1a-H1b = 2JF / 6a-116b = 12Hz, 2H) , H-1a, H-6a), 4.15 (dd, 3H6b-H5 = 3iffib-H2 = 4.4 Hz, 2H, H-1b, H-6b), 3.92 (s, 2H, OH) , 3.85 (m, 4H, H-2, H-3, H-4, H-5), 2.12 (s, 6H, 2xAc), 1.37 (s, 6H, C (0-13); ) 2). 13C NMR (151 MHz, CDCl3, 298 K): 6 ppm 172 (2C, 2C = O), 110.10 (1C, C (CH3) 2), 79.97 (2C, C-2, C-5), 71.81 (2C, C-3, C-4), 66.71 (2C, C-1, C-6), 26.96 (2C, C (CH 3) 2), 21, 07 (2C, 2x Ac). 1,6-Di-O-acetyl-2,5-di-O- (2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl) -3,4-di-O-isopropylidene-Dmannitol 4 Diacetyl mannitol 1 (2 g, 6.53 mmol) and trichloacetimidate 3 (9.65 g, 19.59 mmol) are dissolved in 95 mL of anhydrous CH 2 Cl 2 in the presence of molecular sieves (4, 5 g). The mixture is left for 30 minutes at room temperature before adjusting to -15 ° C. TMSOTf (0.71 mL in 5 mL of CH2Cl2) is then added dropwise. After 50 min, the reaction is treated by the addition of 15 mL of saturated NaHCO 3 solution. The organic phase is separated and washed twice with water (50 mL). After evaporation of the solvents, the product is purified by chromatography on fine silica gel (Et 2 O) to give 4 (3.67 g, 58%) in the form of a white foam. MS, ESI + m / z: 989.6 [M + Na] +, 984.6 [M + NHzi] 1H NMR (400MHz, CDCl3, 298K): δ ppm 5.35 (dd, 3H3H4) = 10.0 Hz, 3-11 / 3'-H2, = 3.6 Hz, 2H, H-3 ', H-3 "), 5.29 (m, 4H, H-2', H- 2 ", H-4 ', H-4"), 5.11 (d, 3HH = 1.1 Hz, 2H, H-1', H-1 "), 4.38 (dd, 3HFRt1a-H1b = 12.1 Hz, 3-J111a-112 = 3.5 Hz, 2H, H-1a, H-6a), 4.28 (m, 4H, H-1b, H-6b, H-6'a, H -6 "a), 4.26-4.18 (m, 4H, H-2, H-5, H5 ', H-5"), 4.08 (dd, 2-11-eb-H6'a) = 12.2 Hz, 3-11-6'b-H5, = 1.9 Hz, 2H, H-6'b, H-6 "b), 3.98 (m, 2H, H-3, H -4), 2.15, 2.11, 2.10, 2.04, 1.98 (5s, 30H, 10x Ac) 1.36 (s, 6H, C (CH3) 2).

13C NMR (101 MHz, CDCl3, 298 K): 6 ppm 170.92, 170.79, 170.09, 169.94, 169.90 (10C, 10xAc) 110.28 (1C, C (CH3) 2 ), 98.80 (2C, C-1 ', C-1 "), 78.46 (2C, C-3, C-4), 77.43 (2C, C-2, C-5), 69 , 83 (2C, C-5 ', -5 "), 69.26 (2C, C-2', C-2"), 68.96 (2C, C-3 ', C-3 "), 66 , 33 (2C, C-4 ', C-4 "), 63.62 (2C, C-1, C-6), 62.64 (2C, C-6', C-6"), 27, 11 (2C, C (CH 3) 2), 21.04, 20.90, 20.88, 20.85 (10C, 10x Ac). 1,6-Di-O-acetyl-2,5-Di-O- (2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl) -D-mannitol 5: AcO 5 OAc 6 AcO AcO AcO 6 OAc 5 .0 3 'AcO 4 AcO AcO OAc -O AcO AcO 6, OAc AcO 6' OAcAcO-O 4 5 .0 AcO AcO O Aco Hd OAc OH Compound 4 (2.63 g, 2, 72 mmol) is dissolved in 6.7 mL of TFA / H 2 O (16: 1 v / v) and the resulting solution is stirred at room temperature. After 30 min the mixture is diluted with 100 mL of ethyl acetate and then neutralized with a saturated solution of NaHCO3 (100 mL). The two phases are separated then the organic phase is washed once with water (50 ml). The aqueous phase is extracted with AcOEt (2x50 mL). The organic phases are combined and dried (MgSO4). After filtration and concentration, the crude residue obtained is purified by chromatography on silica gel (30% AcOEt in Et2O) to give 5 (1.63 g, 1.76 mmol) in the form of a white foam ( 64%). HRMS, TOF ES + calcd for C38H54O26Na [M + Na] + 949.2801; observed 949.2818 1H NMR (400 MHz, CDCl3, 298 K): 6 ppm 5.26-5.35 (m, 4H, H-3 ', H-3 ", H-4', H-4" ), 5.17-5.25 (m, 2H, H-2 ', H-2 "), 5.04 (d, 3HH = 1.4 Hz, 2H, H-1', H-1") , 4.47 (dd, 2Hrt1a-H1b = 2-1H6a-Iffib = 12.5Hz, 2H, H-1a, H-6a), 4.43 (dd, 3H1b-H2 = 3- / H6b-H5 = 3.6 Hz, 2H, H-1b, H-6b), 4.29 (dd, 2-416'a-H6b = 12.0 Hz, 3H6'a-H5, = 5.4 Hz, 2H, H-6'a, H-6 "a), 4.26-4.19 (m, 2H, H-5 ', H-5"), 4.12 (m, 2H, H-6'b, H-6 "b), 3.96-3.90 (m, 2H, H-2, H2.06, 2.0 (5s, 30H, 10x Ac) 5), 3.90-3.81 (m , 2H, H-3, H-4), 2.15, 2.14, 2.10, 170.81, 170.41, 170.10, 169.83 (10C, 10x C = O), 13C NMR (151 MHz, CDCl3, 298 K): 6 ppm 171.92 99.10 (2C, C-1 ', C-1 "), 78.87 (2C, C-2, C-5), 69 79 (2C, C-2 ', C-2 "), 69.31 (2C, C-5', C-5"), 69.23 (2C, C-3 ', C-3 "), 67.98 (2c, C-3, C-4), 66.08 (2C, C-4 ', C-4 "), 64.03 (2C, C-1, C-6), 62.58 (2C, C-6 ', C-6 "), 21.08, 20.99, 20, 91, 20.89 (10C, 10x Ac) Y-O-acetyl-r-O- (2,3 , 4,6-tetra-O-acetyl-α-D-mannopyranosyl) -D-glycerate 6: 20 AcO 6 4 AcO AcO with a solution The addition of TEMPO (32 mg, 0.203 mmol) and Phl (OAc) 2 (3, 27 g, 10.15 mmol). After returning to ambient temperature, the mixture is stirred for 1 hour. The reaction medium is then diluted with 150 ml of ethyl acetate and then washed several times (7 × 50 ml) with a 10% Na 2 S 2 O 3 solution. The aqueous phases are combined and evaporated. The white solid obtained is taken up in 40 ml of water and then acidified with 100 ml of ethyl acetate containing 6 ml of 1N HCl. The aqueous phase is extracted with 2x100 mL of ethyl acetate and the organic phase is washed with 2x50 mL of water. The organic phases are combined, dried and evaporated to give 1.85 g of 6 (95%).

MS, El + m / z: 496.2 [M + NH] +, ESI m / z: 477.3 [MH] 1H NMR (400 MHz, CD3OD, 298 K): 6 ppm 5.40 (dd, m.p. 3-4 / 2-H3 = 3.0 Hz, 3-4 / 2-H1 = 1.8 Hz, 1H, H-2), 5.29 (dd, 3-1H3-H4 = 9.9 Hz, 1H, H-3), 5.25 (t, 3irizi-H5 = 9.9 Hz, 1H, H-4), 5.07 (d, 1H, H-1), 4.57 (dd, 2- 1 / -3'a-H3b = 11.4 Hz, 3-11 / 3'0-1 / 2, = 3.0 Hz, 1H, H-3'a), 4.53 (dd, 3-JH2) -H3b = 6.3 Hz, 1H, H-2 '), 4.34 (dd, 1H, H-3'b), 4.25 (dd, 2.1H60-H6b = 12.4 Hz, -4 / 60-H5 = 5.6 Hz, 1H, H-6a), 4.11-4.18 (m, 2H, H-6b, H-5), 2.14, 2.09, 2, 07, 2.05, 1.96 (5s, 15H, 5Ac).

13 C NMR (101 MHz, CD3OD, 298 K): 6 ppm 172.51, 172.35, 171.67, 171.61, 171.55 (6C, C-1 ', 5xC = O), 98.06 ( 1C, C-1), 74.244 (1C, C-2 '), 70.65 (2C, C-2, C-3), 70.53 (1C, C-5), 67.42 (1C, C -4), 65.33 (1C, C-3 '), 63.77 (1C, C-6), 20.83, 20.78, 20.73, 20.70 (5C, 5Ac). Ammonium 7 (2R) -2 '- (α-D-mannopyranosyl) glyceride 7: H4NO Compound 6 (500 mg, 1.045 mmol) is dissolved in 15 mL of methanol and then 5 mL of ammonia (35%) is added. After stirring for 36 hours at room temperature, the solvents are evaporated to dryness. Chromatography on silica gel eluting with isopropanol / ammonia / water (7/2/1) gave 7 with a yield of 86%. ESI + m / z: 286.2 [M + H] 1H NMR (400 MHz, D 2 O, 298 K): 6 ppm 4.88 (d, 3HH = 1.2 Hz, 1H, H-1), 4.21 (dd, 3H] -H = 7.0 Hz, 3HH 3H, 3.0H, 1H, H-2 '), 4.09 (dd, 3H-H = 3.3Hz, 3HH-H = 1.7Hz, 1H, H-2), 3.93 (dd, 3H-H = 9.5Hz, 3H-H = 3.5Hz). , 1H, H-3), 3.79- 3.89 (m, 2H, H-3'a, H-6a), 3.78-3.68 (m, 3H, H-3'b, H-5, H-6b) 3.66 (t, 3 HH = 9.5 Hz, 1H, H-4).

13C NMR (101 MHz, D20, 298 K): 6 ppm 177.03 (1C, C-1 '), 98.64 (1C, C-1), 78.08 (1C, C-2'), 73.06 (1C, C-5) ), 70.44 (1C, C-3), 70.18 (1C, C-2), 66.91 (1C, C-4), 63.13 (1C, C-3 '), 61.10 (1C, C-6). 2. Extraction of digenase from red algae The red macroalgae Solieria chordalis (J. Agardh) C.Agardh (Rhodophyta) collected at Tinduff (Plougastel-Daoulas) and Ceramium botryocarpum (Griffiths ex Harvey) supplied in the form of lyophilized powders by the Laboratory of Biotechnology and Marine Chemistry (LBCM), University of South Brittany, Lorient, France, were selected for digeneasal extraction (Bondu et al., J Appl Phycol, 2008) Fresh algae, free of their epiphytes, are washed briefly with fresh water and dried. After lyophilization (Alpha 1-4, Christ), they are reduced to a powder state using a ball mill (5min, 300rpm, PM400, Retsch) and then stored in the absence of moisture. . Extraction of the water-soluble compounds The extractions are carried out on 5 g of algae powder mixed with 10 g of Fontainebleau sand and the whole, transferred to the cell, is placed in a rapid solvent extraction system (ASE 300 with solvent controller Dionex). The extraction is carried out with 70% ethanol with magnetic stirring for 2 to 7 min at 40 ° C. and 100 bar pressure. 50% of the solvent is renewed between the two stages.

A second successive cycle makes it possible to carry out a depletion of the algal material. Purification by ion exchange chromatography The hydroalcoholic extracts are taken up in a minimum of distilled water and deposited by slow injection on an automated chromatographic system (Biologic DuoFlow Chromatography System and the associated Bio-Rad software). This technique is based on the ability of a network of resin beads, grafted functional groups, to be able to exchange the counter ions they contain with the charged molecules from the deposited solution.

Elution with water at 0.5 ml / min, on 200 ml of anionic resin (1 × 8, 100-200 μm, Cl-form converted to OH form, Dowex-Fluka Chemika) allows the removal of positively charged molecules. and neutral molecules. The digenase is collected with elution of this resin by 300 ml 1N NaOH at 1 ml / min.

3022458 Desalting eluates The elution technique of the anionic resin with a 1N NaOH solution requires a pH adjustment to neutrality by addition of hydrochloric acid (60%). The chemical reaction gives rise to significant salt formation, which is removed by exclusion gel chromatography (LPGPC: Low Pressure Gel Permeation Chromatography). Depending on their hydrodynamic volume, the eluted macromolecules may or may not penetrate into the porous beads of the gel. The smaller molecules, such as salt, are retained while the larger ones, such as the less retained glycosides, are eluted more rapidly. To do this, the freeze-dried eluates are taken up in a volume of distilled water allowing complete dissolution of the salt (70mL) and they are desalted by fraction of 10mL. The method used here is a column (25mm * 900mm) containing 200mL of Sephadex G 10 gel (cutoff threshold 700Da). The samples are deposited by injection into the system and the column subjected to a flow of water of 0.3 mL / min. At the outlet of the column, a collector (BioFrac Fraction collector Bio-Rad) distributes the effluent in tubes in fractions of 3mL. Elution is monitored by conductimetry and spectrophotometry (manual assay) to detect salt and sugar in each fraction. Fractions containing sugar are pooled and lyophilized. They constitute the digenase sample. He. BIOLOGICAL EXAMPLES 1. Reagent Materials and Methods The following solutions are used for cell culture: AIM V (31035-025, Gibco, France), RPMI 1640 (BE12-115F, Lonza, France), DMEM (BE17-516F, Lonza , France), Saline Phosphate Buffer (PBS, BE17-516F, Lona, France), Pancoll (PO4-60500, Pan Biotech, France), Fetal Calf Serum (FCS, DE14-801F, Lonza, France), Lysing Versalysis solution (A097777, Beckman Coulter, France), penicillin 10,000 IU / Steptomycin 10,000ug (DE17-602E, Lonza, France). The following compounds are also used in culture: Rituximab (RTX, MabThera®, Roche, Switzerland), HLA-DR (baculovirus production), LPS (lipopolysaccharides from Escherichia coli, 0111: B4, Sigma, France), IL-2 (interleukin-2, Proleukin, 18x106U1, WA1239C16, (Chiron, 5621563)), Mannosyl Glycerate (Bitop AG, Germany), Firoin® (Bitop AG, Germany), Mannosyl Glycerate Synthesis (MGs, produced according to the method described in document US2013085149A), digeneasaccharide (produced according to the method described by Bondu et al., J Appl Phycol, 2008), floridoside 3022458 and isofloridoside (purified according to the method described by Simon-Colin et al., Carbohydr Res, 2002 and Simon-Colin et al., Plant Physiol Biochem, 2004), Calcein-AM (CAM, ALX-610-026-M001, Enzo Life Sciences, France), Ethidium Homodimer-1 (EH-1, MGT -M1093-M001, Enzo Life Sciences, France). The following kits are used: Human IFN-y Standard ELISA development kit (900-K27, 5 Peprotech, France), Human IL-2 Standard ELISA development kit (900-K12, Peprotech, France), Human IL-10 Standard ELISA development kit (900-K21, Peprotech, France), PHAGOTESTTM (341060, Glycotope Biotechnology, Germany), Human CD14 Microbeads (130-050 + 201, Miltenyi Biotec, France), EasySepTM Human B Cell Enrichment Kit without CD43 depletion (19154, StemCell Technologies, France), AmershamTM ECLTM Prime Western Blotting Reagent Reagent (RPN2232, GE HealthcareCare, France), Dextran-FITC (46946-100MG, Sigma, France), Annexin Propidium Wlodide (IP) (PN IM3546, Beckman Coulter, France) ). The following antibodies are used for cytometry: anti-CD2O-FITC (clone B9E9, A07772, Beckman Coulter, France), anti-CD4-PE (clone 13B8.2, A 07751, Beckman Coulter, France, anti-CD5-15 PC7 (Clone BL1a, A21690, Beckman Coulter, France), anti-CD14-PC5 (Clone RM052, A07765, Beckman Coulter, France), anti-CD16-PC7 (Clone 3G8, 6607118, Beckman Coulter, France), antiCD19-FITC (Clone J3-119, A07768, Beckman Coulter, France), anti-CD32-PE (Clone 2E1, 1935, Immunotech, France), anti-CD45-FITC (Clone J33, IM0782 PN, Beckman Coulter, France), anti- CD56-PC7 (Clone N901 (NKH-1), A21692, Beckman Coulter, France), IgG1-FITC (Clone 679.1Mc7, A07795, Beckman Coulter, France), IgG1-PE (Clone 679.1Mc7, A07796, Beckman Coulter, France), IgG1-PC5 (IgG1-PC7 (Clone 679.1Mc7, A6607099, Beckman Coulter, France), IgG2a-PC5 (Clone 7T4-1F5, A09148, Beckman Coulter, France), IgG2a-PC7 (Clone 7T4-1F5, A12692, Beckman Coulter, France), IgG2b-FITC (1267, Immunotech, France). used for Western blot analysis: anti-STAT1 (51-9002093, BD Transduction Laboratories, France), anti-STAT1 (pY701) (51-9002099, BD Transduction Laboratories, France), anti-STAT3 (51- -9002097, BD Transduction Laboratories, France), antiSTAT3 (pY705) (51-9002095, BD Transduction Laboratories, France), anti-B-actin (A5441-2ML, Sigma, France).

Cells Peripheral blood mononuclear cells (PBMCs) are isolated on a Pancoll gradient, obtained from donors who are healthy or suffering from haemochromatosis (French National Blood Establishment 5, Brest). They are washed with RPM I and then taken up in AIM V medium. The donors gave their informed consent. Monocytes are purified from isolated PBMCs by positive selection with anti-CD14 combined with magnetic beads according to the manufacturer's recommendations (Miltenyi Biotec).

Chronic Lymphocytic Leukemia (B-CLL) B cells from untreated patients are isolated on a Pancoll gradient. LLC-B purity is determined by CD19 + / CD5 + phenotyping. It must be greater than 85%. Otherwise, purification of LLC-Bse cells is done by negative selection on magnetic beads according to the manufacturer's recommendations (StemCell Technologies), in order to obtain a purity higher than 85%.

The Daudi cell line (Burkitt B-cell lymphoma (ECACC)) was maintained in DMEM supplemented with 20% FCS and Penicillin (1000 IU) / Streptomycin (1000 μg) at 37 ° C. 5% CO2. Murine cells EL4-huCD20, graciously donated by Dr. Loisel (Animal Facility, University of Western Brittany, Brest), are used.

The phenotyping of the cells is carried out with the following fluorochromes: anti-CD4-PE (Clone 13B8.2), anti-CD5-PC7 (Clone BL1a), anti-CD14-PC5 (Clone RM052), anti-CD16-PC7 ( Clone 3G8), antiCD19 (Clone J3-119), anti-CD32-PE (Clone 2E1), anti-CD45-FITC (Clone J33), anti-CD56 (Clone N901 (NKH-1)), IgG1-FITC, IgG1 -PE, IgG1-PC5, IgG1-PC7, IgG2α-PC5, IgG2α-PC7, IgG2b-FITC (Beckman Coulter, France).

Cytokine assay in culture supernatants The changes in concentration of IL-2 and IL-10 as a function of time in culture supernatants of PBMC grown with or without purified digenase (10 μM) were assayed by ELISA according to the recommendations of the manufacturer (Peprotech).

Western Blot Analysis PBMCs are treated with or without purified digenease (10 μM) at different times. The cells are then taken up in Leammli buffer and the proteins are denatured for 3 minutes at 95 ° C.

After separation of the proteins on SDS-PAGE (8% tris-glycine gel), they are transferred to a nitrocellulose membrane (0.45 μm, Biorad, France). These membranes are saturated for 1 hour with a saturation solution (TBS-T buffer: 0.1% (v / v) Tween-20, 150 mM NaCl, 200 mM Tris-HCl pH 7.5, containing 5% BSA for the anti-human antibodies. phosphorylation or 5% milk for the other antibodies) at room temperature with stirring. They are incubated overnight at 4 ° C with the following primary antibodies: anti-STAT1 (1: 4,000), anti-STAT1 (pY701) (1: 1,000), anti-STAT3 (1:10,000), anti -STAT3 (pY705) (1: 500), anti-B-actin (1:20 000). After that, the membranes are washed 4 times with TBS-T buffer and incubated with the appropriate secondary antibody (anti-mouse Ig-HRP, 1: 2000, Cell Signaling) for one hour at room temperature with shaking. The signals are revealed with the ECL Prime Detection kit and quantified with Bio1D software (Vilber-Lourmat, France).

The signals are normalized to B-actin. Antibody-Dependent Cellular Cytotoxicity (ADCC) PBMCs, obtained after Pancoll gradient purification, are taken up in AIMV medium to obtain a cell concentration of 1.5 × 10 6 cells / ml. 200 .mu.l of cells are seeded in a 96-well plate with a round bottom. They are cultured in the presence or absence of digenease or Firoin® (10 μM) for 5 days at 37 ° C. under 5% of CO2. In parallel, Daudi cells are cultured for use as target cells in the ADCC test. After 5 days of culture, the Daudi cells are recovered and treated with 40 μl of CAM (1 μg / ml) for 10 6 cells for 15 minutes. They are then washed twice, and they are resuspended in AIMV medium at a concentration of 0.4 × 10 6 cells / ml. 50 μl of Daudi cells labeled with CAM are added to wells containing PBMCs with an effector / target cell ratio of 15: 1. RTX or HLA-DR (300ng / ml) are added to verify the potentiation of the digenase or Firoin® response. The cells are incubated for 4 hours at 37 ° C. under 5% CO 2. Cytotoxicity is evaluated by flow cytometry after the addition of 17 μl of EH-1 (1 μg / ml) for 15 minutes at room temperature. The tests are carried out in triplicates (Papadopoulos et al., J. Immunol Methods, 1994).

The controls used in this experiment are unmarked target cells, CAM-labeled target cells, target cells that have undergone DMSO treatment prior to EH-1 labeling, unlabeled effector cells, and effector cells. marked with EH-1.

Determination of viability of the cells by labeling with Annexin V / IP The cells are seeded so that their concentration in the Annexin V / IP test is between 5.105 and 5.106 cells. Buffer Binding Buffer (BB) 1x is prepared by diluting the BB 10x buffer in water. The IP is reconstituted at 250 μg / ml by adding 1 ml of 1x BB buffer.

In the Annexin V / IP assay, the cells are washed with cold PBS and centrifuged for 5 minutes at 500g at 4 ° C. The supernatant is removed and the cell pellet is resuspended in 104.1 of 1x BB buffer. 1 μl of Annexin V (25 μg / ml) and 5 μl of IP (250 μg / ml) are added per 100 μl of cells. After incubation for 15 minutes at 0 ° C in the dark, 400 μl of cold 1x BB buffer is added prior to cytometric analysis.

Endocyte Activity The endocytic activity of polynuclear cells was measured by the integration of Dextran-FITC (Sigma-Aldrich). 100 μl of whole blood is put at 4 ° C or 37 ° C with or without digenase. After 24 hours, lmg / ml Dextran-FITC was added to whole blood to measure endocytosis at 37 ° C and 4 ° C. After 30 minutes, 1 hour, 1 hour 30, 2 hours, 2 hours 30, the red blood cells are removed by osmolysis, then the cells are recovered after centrifugation and 3 washes respectively in PBS NaN3 3% cold, PBS NaN3 1% BSA 1% cold, then PBS BSA 1% cold. Cells in cold PBS are analyzed by flow cytometer. Phagocytosis The PHAGOTESTTM diagnostic kit is used to evaluate phagocytosis in a peripheral blood sample, taken on heparin, according to the manufacturer's recommendations.

3022458 Animal Models Sopf / NOD.Cg-Prkdc Scid immuno-deficient 7 week old female mice are from Charles River (L'Arbresle, France). Immune competent SOPF / C57BL / 6JRJ mice are 7 weeks old with a weight of 23-25 g at the beginning of the study and come from the January breeding (L'Arbresle, France). The conditions of the protocol are in line with European requirements (EEC / 86/609), and the recommendations set out in the Guide for the Care and Use of Laboratory Animals. In all the experiments with the inoculation of the tumor, the male mice of strain SOPF / C57BL6JRJ (January Breeding, L'Arbresle, France) aged 7 weeks with a weight of 23-25 g at the beginning of the study, receive intravenous injection with 8 × 10 3 EL4-huCD20 cells in 100 μl of physiological phosphate buffer at day 0. Before each experiment, the stability of hu-CD20 expression was verified by cytometric analysis. At day 13 (13 days is the time required for quantifiable growth of the tumor), a single dose of Rituximab 12mg / kg (ch-IgG1k anti-CD20, ch-C2B8 was injected intravenously. in 6 groups of 8. The digenase molecule was diluted in sterile water for a mother concentration of 50 mg / ml Two other solutions are prepared from the stock solution to load the ALZET pumps at 2 mg doses The digenase was infused for 28 days from day 13. The 48 ALZET 20 pumps were loaded with 200 μl of sterile water or digeneaside according to the filling procedure described by the supplier, and then were implanted subcutaneously from day 13 after implantation of the tumor cells ALZET pumps were removed 35 days after implantation according to the recommendations of the supplier. water with the pump over 28 days; Group 2 receives only the molecule digénéaside at a concentration of 2 mg / mouse for 28 days; Group 3 receives only the digenase molecule at a concentration of 4 mg / mouse for 28 days; group 4 receives only one injection of Rituximab and sterile water with the pump for 28 days; Group 5 receives an injection of Rituximab and the digenease molecule at a concentration of 2 mg / mouse for 28 days; group 6 receives an injection of Rituximab and digeneaside at a concentration of 4 mg / mouse for 28 days. The animals are observed daily to detect mortality and morbidity. Body weight is recorded 1-2 times a week or more at the beginning of the study.

Buprécare (Axience, 03760087151244) was administered to provide analgesia for 3 days following implantation of the pump. During the first symptoms of paralysis of the lower limbs, the mice are euthanized. All living mice are euthanized on D187, and the organs are collected, weighed and analyzed in the Morvan CHU's pathology laboratory.

The experiments carried out with the immunodeficient mice were carried out according to the same method. Pathology examination The liver, heart, lungs, spleen, intestine and kidneys of mice treated or not treated with Rituximab and digeneasate are collected at each euthanasia and fixed with buffered formalin. These organs are examined macroscopically to collect areas of interest for histological study. These organ fragments are then embedded in paraffin block. Microtome sections are made from these blocks, then stained with hemalun-eosin-saffron. The expression of CD20 (Clone L26-Dako-Denmark) is evaluated by immunohistochemical technique on these fixed and paraffin-embedded tissue sections (Ventana-Benchmark automaton). 2. Therapeutic effect of digenase alone or in the presence of another immunostimulant agent demonstrated in vitro. Study of the cytotoxicity of digenease on healthy cells and LLC-B. Daudi cells were cultured with digenase (10 mM). . As shown in Figure 1, digenease (67.7%), Floridoside (71.2%) and Isofloridoside (79.3%) are nontoxic at a dose of 10mM on Daudis cells at 24H. (Annexin V / PI). Their viability is close to that of the control cells (78.2%). The positive control is actinomycin D (10.2%).

Thus, after 24 hours, the viability of the treated cells (except positive control) is similar to the untreated Daudi cells. Similar results are obtained for the cytotoxicity of Firion® (mannosylglycerate from bacteria). Its impact on cell survival of patients with chronic lymphocytic leukemia B (CLL-B) is small (Figure 2). Secretion of cytokines The modulation of the cytokine profile of PBMCs in culture was evaluated by the ELISA technique. The variations in IL-2, IL-10 and IFN-γ concentrations are determined in the culture supernatants of the PBMCs incubated with digenase and Floridoside at a concentration of 10 μM and / or 10 μg / mL of LPS for 6 days.

An increase in IFN-γ release in supernatants with digeneaside is observed (Figure 3). PBMCs acquire the ability to secrete IFN-γ in a time-dependent manner (Figure 3). Indeed, from 5 days of culture, digeaginase-activated PBMCs secrete a 7.5-fold higher IFN-γ ratio than PBMC alone (470.33pg / ml vs 62.41pg / ml, respectively). The statistical method used to discriminate the averages of the different groups is the procedure of the Fisher significant minimal differences (LSD) at the 95.0% confidence level. There is no significant difference between the amount of IFN-γ secreted by the digenase action and that secreted under the action of LPS on D5. Analysis of the Impact of Digénéaside and Firoin® on PBMCs To analyze the transmembrane signal of digénéaside and Firoin® on PBMC, the expression of STAT1 and STAT3 proteins was studied by Western Blots. The kinetics of expression were studied after 4 hours, 24 hours, 48 hours, and 72 hours with both compounds and LPS. Digeneasomer stimulates the activation of the STAT3 protein (FIG. 4a and FIG. 4b) but not of STAT1 (results not shown). Over time, a change in the expression of phosphorylated STAT3 (FIG. 4a and FIG. 4b) is noted. At 4 hours and 48 hours, the expression of phosphorylated STAT3 is observed for Firoin® and digeneasaccharide. At 24 hours and 72 hours, the intensity of the bands decreases reflecting a weaker expression of phosphorylated STAT3. Actin serves as a control of manipulation.

Phosphorylation of STAT3 is a pathway leading to the production of IFN-γ. ADCC-Dependent Cellular Cytotoxicity ADCC is a mechanism of cell-mediated immunity, in which an effector cell actively destroys a target previously coated with specific antibody. This mechanism is induced mainly by NK cells, but monocytes and neutrophils can also play this role. The experimental conditions were defined as follows: PBMC / target / 300 ng / ml RTX for 4 hours of incubation. The protocol followed is described by Papadopoulos et al. (Papadopoulos et al., Immunol Methods, 1994). This protocol is based on the use of fluorescent CAM (FL1) and EH-1 (FL3) probes. Four cell populations are studied, intact effector cells (CAM- / EH-1-), live targets (CAM + / EH-1-), dead effector cells (CAM- / EH-1 +) and dead targets ( CAM + / EH-1 +).

The first study on the action of digenase with RTX (Figure 5) shows an effect of the molecule at the cell level. An increase in lysis of the target cells is observed. Similarly, the Firoin® also induced an increase in cell lysis by PBMCs (FIG. 6b). The base values (FIG. 6b) of 10.5% (1.4% standard deviation) show the action of lysis of the antibody alone on the effector cells and the target cells. When digenase is added (Figure 6a), lysis increases to 15.7% (3.4% standard deviation) and 15.8% for Firoin® (0.4% standard deviation). (Figure 6b). A homogeneity of the values is noticed between digénéaside and Firoin®. In a second donor the baseline lysis is 74.9% (2.1% standard deviation) whereas with Firoin® it is 84.2% (1.4%). % standard deviation) (Figure 6b).

Activation of monocytes in the presence of Mannosylalycerate The impact of mannosylglycerate at 10 μM on the activated monocyte population was studied for 5 days on different cells of whole blood. Figure 8 shows that this population of cells is doing well after 5 days, from 13.9% (without Firoin®) to 21.9% of monocytes (with Firoin®). Phagocytosis The ability of cells present in the total peripheral blood to phagocytose fluorescent bacteria was studied. The method was visualized in flow cytometry. The phagocytosis of fluorescent bacteria by leukocytes present in a peripheral blood sample taken on heparin was evaluated by the PHAGOTEST ™ Kit. The percentage of phagocytes having ingested bacteria is given by flow cytometry reading. The heparinized blood is incubated with Escherichia coli / FITC bacteria at 37 ° C, a sample is stored at 4 ° C and serves as a negative control. Various compounds (Floridoside, Isofloridoside and Digeneaside) at a concentration of 10mM were tested by this method. On duplicate results, tests were performed with cells alone (42.5% phagocytosis), Floridoside (47.6%), Isofloridoside (51.2%) and digeneasate (77.4%). ).

Floridoside and Isofloridoside somewhat increase the phagocytosis capacity of granulocytes (Figure 9). An experiment was carried out with Dextran-FITC. The blood sample is in the presence of 10 μM of Firoin® for 24 h at 4 ° C. (negative control) and 37 ° C. (test). After 24 hours, a solution of Dextran-FITC (1 mg / ml) is added, and the samples are taken after 1H, 2H, 3H, 4H, 5H of incubation. After lysis of red blood cells and washes to remove excess Dextran-FITC, the samples are read in flow cytometry. Phagocytes are the selected population. Figure 10a shows that the integration of Dextran-FITC, in polynuclear treated for 24 hours with Firoin®, begins after 2 hours of incubation with it to reach 90.7% after 5 hours of incubation. According to Figure 10b, the integration of dextran-FITC, in the 3022458 polynuclear treated for 48 hours with Firoin®, is faster than 24 hours, since it reaches a maximum of 82.5% at 2 30 hours. Thus, FIG. 10 shows an increase in the power of ingestion of polynuclear cells in the presence of Mannosylglycerate, and this as early as 24 hours. Ingestion is shown on bacteria and Dextran-FITC. 3. Therapeutic effect of digeneaside alone or in the presence of another immunostimulatory agent demonstrated in vivo To observe the immunomodulatory effect in-vivo on the development of a transplanted tumor, digeneaside was inoculated together in immuno-competent mice. SOPF / C57BL / 6JRJ and immuno-deficient mice SOPF / NOD.Cg-Prkdc Scid. The mice were observed daily and euthanized in case of paralysis. The SOPF / C57BL / 6JRJ mice were autopsied. Immuno-deficient Mouse Model The immuno-deficient mice were inoculated with 3 × 10 6 cells of the Daudi line in 100 μl intravenously. After 5 days, the mice were divided into 5 groups: a placebo group receiving PBS, a group receiving 40 μg of RTX, a group receiving 40 μg of RTX and the 4.106 effector cells (1.5 × 10 6 cells). NK and 2.5.106 monocytes), a group receiving 40 μg of RTX and 4.106 effector cells associated with a continuous digenase injection for 14 days, a group receiving 40 μg of RTX and 4.10 6 effector cells associated with an intraperitoneal injection 2 μg of IL-2 and continuous injection of digeneaside for 14 days. The dosage of IL-2 was chosen to promote the transformation of these NK cells into LA K. The results obtained show that RTX makes it possible to improve the survival of animals grafted with a human lymphoma. The addition of digeneaside helps to delay early deaths (Figure 11). - Immune competent mouse model 3022458 46 Therapeutic effects of Rituximab and digénéaside The protocol followed for treatment with RTX is the same as that described by Daydé et al. (Daydé et al., Blood, 2009).

Thus, the same number of EL4-huCD20 cells were injected into the mice and they were treated with a dose of RTX (12 mg / kg) judged optimal. For all mice, the injection of 8 × 10 3 EL4-huCD20 cells leads to the development of tumors involving lymph nodes, affecting the spleen, liver and spinal cord. Bioluminescence analyzes showed an exponential increase in activity corresponding to the in vivo growth of lymphatic tumors with 73% at day 9 and 100% at day 13 of mice with lymphatic development. Daydé's team showed a median of 22-day survival in mice that received no treatment. In the case of the present invention a median survival of 38 days was obtained. The injection of RTX and digeneaside was performed on day 13, which is judged to be the peak day for tumor development. In the case of the present invention, the median survival for the dose of 12 mg / kg is 41 days (Figure 12). At day 13, after transfer of the tumor cells, 12 mg / kg of RTX was injected in a single dose, then the mice were perfused for 28 days with a digenease dose of 2 mg / mouse or 4 mg / mouse. Median survival was observed for RTX alone for 41 days. One mouse survived and was euthanized thereafter. A slight difference was observed between the two arms representing treatment with digeneaside alone, at a concentration of 2 mg and 4 mg. The median survival is homogeneous from 56 days to 53 days. In both arms combining RTX and digeneaside, again no difference was observed. In both cases, two mice died only. For the 4mg dose, they died earlier on days 36 and 38, while for the 2mg dose, both mice died on days 46 and 73.

3022458 47 All the mice in the control group died after 96 days. The groups treated with the digenase molecule alone have a survival benefit of 37.5% and 50% at 187 days after inoculation of the tumor cells, compared to the control group.

The mice in the RTX alone group had a 25% survival benefit over the control group. The mice of the group treated with the RTX-digenease combination have a better survival rate, since 75% of the animals survive 187 days after the inoculation of the tumor cells, whatever the dose injected.

Pathology Examination EL4-huCD20 cells were analyzed by flow cytometry and showed CD2O-FITC labeling. In the pathological study, the mice that died in the first 40 days were first differentiated (FIG. 13). In the case of the group of mice not injected, two out of three mice present a general tumor with, on gross examination, invasion of the hepatic hilum, kidneys and peritoneum. On histological examination, the lungs are infiltrated massively by a tumor expressing CD20 in immunohistochemistry.

In the group receiving a single dose of RTX, one in two mice has a large lung tumor massively expressing the CD20 antigen, with no infiltration of other organs. In the group that received the continuous injection of digeneide 2mg, the two mice did not have obvious tumors observed macroscopically, but in the immunohistochemical study, showed interstitial pulmonary or lymphomatous infiltration of the liver and pancreatic hil , by positive CD20 elements was observed. In the group receiving digeneaside 4mg, three mice are studied. They have no obvious macroscopic abnormality. In the immunohistochemical study, infiltration of the hilar lymph nodes labeled with the anti-CD20 antibody was observed without tumor formation. On the other hand, these two mice show a tumor focus in the renal hilum and the other a peri-renal lymphomatous mass. The third presents a large mediastinum and a large mesenteric tumor. In histology, it exhibits massive cardiac infiltration and pulmonary hilarity by a CD20 positive lymphoma population. Finally, two mice of the RTX-digenease 4mg group died in the first 40 days. One of them does not present any macroscopic anomaly with some CD20 positive elements dispersed in the spleen and a tumor nodule in contact with the pancreas. The second mouse has a mediastinal-pulmonary tumor expressing the CD20 antigen. The mice without treatment all died after the 96th day. All other mice were euthanized at day 187 (Figure 14). Of the 3 mice that received a 2mg digenease injection, only one mouse showed an ecchymotic liver, two others would have a normal macroscopic appearance with some CD20 + cells in the hilar lymph nodes of the lung. Of the 4 mice given a 4mg digenease injection, a single mouse will show interstitial and perivascular lymphoid infiltrates in the liver and kidney. The others have a normal macroscopic appearance with some CD20 + cells in the lungs and hilar ganglia of the lung. Figure 15 shows hilar lymphoid infiltrates in the lung as well as interstitial and perivascular suspicious lymphoid infiltrates in the liver and kidney, according to HES staining. On images with anti-CD20, some CD20 + cells are observed in the lung and lymph nodes, as well as in the spleen and liver.

The two mice that received an injection of RTX, have a normal macroscopic appearance with some CD20 + cells in the hilar lymph nodes of the lung. Of the 6 mice injected with continuous digeneaside 2mg and a single injection of Rituximab, one mouse showed interstitial and perivascular lymphoid infiltrates to the liver and one to the kidney. Otherwise, all six have a normal macroscopic appearance with some CD20 + cells in the hilar lymph nodes of the lung, one at the spleen. Finally, of the six mice injected with continuous digeneaside 4mg and a single injection of Rituximab, only one mouse showed interstitial and perivascular lymphoid infiltrates in the liver and kidney. Otherwise all have a normal appearance in macroscopy with some CD20 + cells in the hilar lymph nodes of the lung and one in intra-pulmonary interstitial spaces.

Tumor development in mice euthanized at day 187 is under control of the immune system. In this immuno-competent mouse model, the action of RTX is enhanced by the immunostimulatory action of digenase.

These results clearly show that in immunocompetent mice, the association between RTX and digeneaside slows the development of the tumor within the tissues. The anatomo-pathological sections show the appearance of a balance between the immune system and the tumor. No aggregate is present. Immune cells have the ability to stick to tumor cells. The examples above are given for illustrative and not limiting.

Claims (11)

REVENDICATIONS1. A compound of the following formula (I): ## STR1 ## or a pharmaceutically acceptable salt acceptable thereof, such as in the form of a base addition salt, or a stereoisomer thereof, or a mixture of stereoisomers thereof in any proportion, wherein: - n represents a number integer from 0 to 3, preferably n represents 0, - X represents O, NR3 or S, preferentially X represents O, - R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4 , CH 2 NR 4 R 5, P (O) (OR 4) (OR 5), P (O) (OR 4) R 5, SO 2 (OR 4) or SO 2 NR 4 R 5, - R 2 represents H, (C 1 -C 6) alkyl, OR 6, CH 2 OR 6 or CH 2 NR 6 R 7, and R3, R4, R5, R6 and R7 are each, independently of each other, H or (C1-C6) alkyl, for use as a medicament. A compound for use according to claim 1, characterized in that it has the following formula (I-1): ## STR1 ## or a pharmaceutically acceptable salt thereof. 3. Compound for its use according to claim 1 or 2, characterized in that R1 represents CO2R4, COR4, CH2OR4, C (O) NR4R5, C (O) N (OR5) R4 or CH2NR4R5, preferentially CO2R4, and / or R2 represents CH2OR6 or CH2NR6R2. 4. Compound for use according to any one of claims 1 to 3, characterized in that it is 2-O-α-D-mannopyranosyl-D-glycerate or a pharmaceutically acceptable salt thereof. 10 5. A compound, or a pharmaceutically acceptable salt thereof, such as in the form of a base addition salt, or a stereoisomer thereof, or a mixture of stereoisomers thereof in any proportion, as defined in any one of claims 1 to 4 for use as an immunostimulatory medicament or for the prevention and / or treatment of a condition comprised in the group consisting of neoplastic pathologies, particularly for prevention of neoplastic pathologies by means of vaccine amplification, and / or infectious pathologies, in particular HIV-related pathology. 6. Extract of at least one alga belonging to the order ceramiales or bangiales for its use as a medicament, in particular an immunostimulatory drug and / or for the prevention and / or treatment of a pathology included in the group consisting of neoplastic pathologies and infectious pathologies, said extract comprising a content of 2-O-α-D-mannopyranosyl-D-glycerate in the range of 0.1% to 2.0%, preferably 0.5% to 1.5% by weight relative to the total weight of the extract, expressed as dry extract. 3022458 52 7. Extract according to claim 6, for its use as a medicament for the prevention of neoplastic pathologies by vaccine amplification or as a medicament for the prevention and / or treatment of an infectious pathology which is a related pathology. to HIV. 5 8. Process for the synthesis of compounds as defined in any one of claims 1 to 7, characterized in that said process comprises the following steps: (1) formation of a hexopyranose dimer, in which the two hexopyranoses are connected between them via a suitably substituted glycolic linkage and, on the other hand, said hexopyranoses are suitably protected, if appropriate and preferably identical, (2) cleavage and oxidation of the CC bond of the glycolic unit; and (3) recovering compounds according to any one of claims 1 to 15, after eventual deprotection, salt formation or subsequent functionalization, if appropriate. 15 A pharmaceutical or nutraceutical composition comprising: at least one component selected from the group consisting of: a compound, a pharmaceutically acceptable salt thereof, a stereoisomer thereof, a mixture of stereoisomers thereof in all proportions as defined in any one of claims 1 to 4 and an extract as defined in claim 6; a pharmaceutically or nutraceutically acceptable vehicle, and optionally at least one other anti-tumor agent. A product comprising: - at least one component selected from the group consisting of: a compound, a pharmaceutically acceptable salt thereof, a stereoisomer thereof, a mixture of stereoisomers thereof in any proportion, such as defined according to any one of claims 1 to 4 and an extract as defined according to claim 6; and 3022458 53 - at least one other anti-tumor agent; as a combination product for simultaneous, separate or spread use over time for the prevention and / or treatment of a neoplastic pathology. 5 11. Product for use according to claim 10, said other anti-tumor agent being an anti-tumor antibody being included in the group consisting of rituximab, trastuzumab, cetuximab, bevacizumab, gemtuzumab ozagamicin, yttrium-90 Ibritumomab-Tiuxetan, alemtuzumab, tositumomab, ofatumumab.