WO2011106993A1 - Gold nanoparticles modified by aminopyrimide, preparation method and use thereof - Google Patents

Abstract

Gold nanoparticles modified by amino pyrimide, the preparation method and the use thereof are disclosed. Amino pyrimidine is preferably selected from 2-thiol-4,6-diamino pyrimidine, 2-thiol-4-amino pyrimidine and/or 2,4-diamino-6-mercaptopyrimidine. The particle size of gold nanoparticles is 1.5-10.0 nm and the molar ratio of amino pyrimidine to Au is 0.1:1-0.9:1. The gold nanoparticles have broad-spectrum antibiotic effect.

Description

 Aminopyrimidine modified gold nanoparticle, preparation method and use thereof

 The present invention relates to a series of aminopyrimidine modified gold nanoparticles, a process for the preparation of the nanoparticles and their antibacterial use. Background technique

 At present, the research and development of nano-metal antibacterial drugs at home and abroad mainly focuses on nano-silver, nano-titanium dioxide and nano-oxidation. However, nano-silver is unstable to light and harmful to human body. The antibacterial effect of nano-titanium dioxide depends on the light source, and the dosage of nano-oxidation is too high. The development of nano gold as an antibacterial agent is not much. Sabo-Attwood TL et al. (Norman, RS; Stone, JW; Gole, A.; Murphy, CJ; Sabo-Attwood, TL, Targeted photothermallysis of the pathogenic bacteria, pseudomonas aeruginosa, with gold nanorods. Nano Lett. 2008, 8, (1), 302 - 306) The use of gold nanorods to absorb the characteristics of near-infrared light heating for sterilization, but also requires a near-infrared light source of a certain power. Xu bing et al ( Gu, H.; Ho, PL; Tong, E.; Wang, L.; Xu, B., Presenting vancomycin on nanoparticles to enhance antimicrobial activities. Nano Lett 2003, 3, (9), 1261-1263 It is mentioned that the modification of the antibacterial drug vancomycin to gold nanoparticles can improve the antibacterial effect against vancomycin-resistant bacteria, but it still has little effect on E. coli, and the synthesis process is complicated.

2-Mercaptopyrimidine or 4-amino-2-mercaptopyrimidine is considered to have antibacterial properties by inhibiting the synthesis of bacterial t-RNA. Mostafa S. L et al (mostafa, SI; Hadjiliadis, N" Biologically active 2-thione-4, 6-diamino-5-hydroxypyrimidine transition metal complexes. Transition Metal Chemistry 2008, 1-6) tested 2-mercapto-4, The antibacterial activity of 6-diamino-5-hydroxypyrimidine showed a slight antibacterial effect when its concentration was above 20 mg/mL; when the pyrimidine molecule was coordinated with metallic silver, the antibacterial concentration was reduced to 10 mg/mL. Sayed HH et al (Sayed, HH; Shamroukh, AH; Rashad, AE, Synthesis and biological evaluation of some pyrimidine, pyrimido [2, lb][l, 3] thiazine and thiazolo [3, 2-a] pyrimidine derivatives. Acta Pharm 2006, 56, (2), 231-44) Tested the derivative of 2-sulfo-4,6-diaminopyrimidine - 1,3,4-trihydroxy-2-indolyl-4,6-di ( The antibacterial activity of phenylhydrazinylaminopyrimidine has a slight antibacterial effect at a concentration of 25 g/ml. The antibacterial effects of these drugs are too weak. Jingfang Zhou et al ( Zhou, J.; Beattie, DA; Ralston, J. Sedev, R., Colloid stability of thymine-functionalized gold nanoparticles. Langmuir 2007, 23, (24), 12096-12103 ) A long-chain alkyl-modified thiol thymine, 1-(10-fluorenyldecyl)-5-mercaptopyrimidine, was synthesized by a benzene/water two-phase method. Gold nanoparticles, which are completely dispersed only in aqueous solutions with a pH > 12.3. Weili 8 et al (Shi, W.; Sahoo, Y.; Swihart, M. Τ·, Gold nanoparticles surface-terminated with bifunctional ligands. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2004, 246, (1-3), 109 -113) 4-aminothiophenol-modified gold nanoparticles synthesized in a sterol solution under ice bath are heavily agglomerated, and the ligand of the particles is similar in structure to 2-mercapto-4,6-diaminopyrimidine. Selvaraj, V. et al. (Selvaraj, V.; Alagara, Μ·; Hamerton, I.; Analytical detection and biological assay of antileukemic drug using gold nanoparticles. Electrochimica Acta 2006, 52, 1152-1160) After the gold nanoparticles were mixed, 6-mercaptopurine-modified gold nanoparticles were obtained, and the drug effect was improved, but the nanoparticles were agglomerated and could not be preserved. Summary of the invention

 It is an object of the present invention to provide a series of gold nanoparticles whose surface is modified by an aminopyrimidine molecule which is one or more 2-mercapto-4,6-diaminopyrimidines, 2-mercapto-4 Aminopyrimidine and 2,4-diamino-6-mercaptopyrimidine. This series of gold nanoparticles can be used as an antibacterial drug. Another object of the present invention is to provide a process for the preparation of the aminopyrimidine modified gold nanoparticles. It is still another object of the present invention to provide an antibacterial drug comprising aminopyrimidine modified gold nanoparticles. It is yet another object of the present invention to provide the use of said aminopyrimidine modified gold nanoparticles, including in the preparation of antibacterial agents. It is yet another object of the present invention to provide a method of treating bacterial infections using the aminopyrimidine modified gold nanoparticles.

 The technical solution for achieving the above object is as follows:

 In one aspect, the invention provides a gold nanoparticle wherein the surface of the gold nanoparticle is modified by an aminopyrimidine molecule.

 Preferably, the aminopyrimidine molecule modified on the surface of the gold nanoparticle is one or more of 2-mercapto-4,6-diaminopyrimidine, 2-mercapto-4-aminopyrimidine and/or 2,4-diamino-6. - Mercaptopyrimidine.

 Further preferably, the aminopyrimidine molecularly modified gold nanoparticle provided by the invention has a particle size ranging from 1.0 to 10.0 nm; the molar ratio of the aminopyrimidine molecule to the gold element in the nanoparticle is 0.1:1 to 0·9:1 .

The above aminopyrimidine modified gold nanoparticle aqueous solution may be stored at 4 ° C for at least one year at a concentration of 0.1 to 1 mg / ml, and may be stored at 4 ° C or -20 ° C for at least one year after lyophilization, freeze-dried particles Still soluble In the water.

 In another aspect, the present invention provides a method for preparing the above gold nanoparticles, the steps of which include:

 (1) dissolving and mixing chloroauric acid and aminopyrimidine to form a mixed solution;

 (2) reducing agent (for example, sodium borohydride or sodium ascorbate) to reduce chloroauric acid in the above mixed solution to form aminopyrimidine-modified gold nanoparticles;

 (3) Purification of aminopyrimidine modified gold nanoparticles.

 Preferably, the molar ratio of the chloroauric acid to the aminopyrimidine molecule in the mixed solution in the step (1) is 1: 1 to 1 : 10; the molar ratio of the chloroauric acid to the reducing agent is 1: 1 ~ 1 : 10 .

 Preferably, the chloroauric acid, the aminopyrimidine and the reducing agent are dissolved in a polar solvent or a non-polar solvent, and further preferably, the polar solvent is selected from the group consisting of water, disulfoxide, decyl alcohol, ethanol, tetrahydrofuran, The polar solvent is selected from the group consisting of toluene and diphenylbenzene.

 Preferably, the mixed solution further comprises an organic acid or a mineral acid, preferably, acetic acid, propionic acid or hydrochloric acid; the volume content of the acid in the mixed solution is 0.5% to 10%;

 Preferably, the non-ionic surfactant is further included in the mixed solution, and the nonionic surfactant is preferably Triton X-100, Tween and polyethylene glycol, and the volume content of the nonionic surfactant in the mixed solution is 1 %~ 10%.

 Preferably, when a non-polar solvent is used, the non-polar solvent further comprises a phase transfer catalyst, and the phase transfer catalyst is preferably tetra-n-octyl ammonium bromide, tetrabutylammonium bromide, tetrabutyl hydrogen sulfate. Ammonium, benzyltriethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, phase transfer catalyst in a non-polar solvent at a molar concentration of l~10 mM .

 Preferably, the reaction time of the above preparation method is 0.5 hours or more, and the reaction temperature range is below room temperature, preferably between room temperature and zero degrees Celsius, including room temperature and zero degrees Celsius; further preferably, the reaction time is 0.5 to 3 hours.

 In still another aspect, the present invention provides an antibacterial agent comprising aminopyrimidine modified gold nanoparticles.

 Preferably, the antibacterial agent is selected from the group consisting of one or more anti-Gram-negative bacteria drugs, anti-Gram-positive bacteria drugs, and/or anti-multidrug resistant clinical isolate drugs.

 Further preferably, the Gram-negative bacteria comprise Escherichia coli, Pseudomonas aeruginosa, Shigella dysenteria, Salmonella typhi, Proteus and Cholera; the Gram-positive bacteria comprise Staphylococcus epidermidis, Pneumococci, Diphtheria Bacillus and tetanus; the multi-drug resistant clinical isolate comprises multi-drug resistant E. coli and Pseudomonas aeruginosa.

 In still another aspect, the present invention provides the use of gold nanoparticles for the preparation of antibacterial agents.

Preferably, the antibacterial agent is selected from the group consisting of one or more anti-Gram-negative bacteria drugs, anti-Gram-positive bacteria drugs, and/or anti-multidrug resistant clinical isolate drugs. Further preferably, the Gram-negative bacteria comprise Escherichia coli, Pseudomonas aeruginosa, Shigella dysenteria, Salmonella typhi, Proteus and Cholera; the Gram-positive bacteria comprise Staphylococcus epidermidis, Pneumococci, Diphtheria Bacillus and tetanus; the multi-drug resistant clinical isolate comprises multi-drug resistant E. coli and Pseudomonas aeruginosa.

 In yet another aspect, the present invention provides a method of treating a disease caused by a bacterium and a disease, disorder or condition associated therewith, the method comprising administering a therapeutically effective amount of the above aminopyrimidine modified gold nanoparticle after bacterial infection in a mammal Granules or the above antibacterial drugs.

 Preferably, the method of treatment comprises administering a therapeutically effective amount of aminopyrimidine modified gold nanoparticles to a patient by intravenous injection, intramuscular injection, subcutaneous injection, intradermal injection, intraperitoneal injection, or oral administration, and may be administered in a single administration. The drug can be administered twice a day, once a day, three times in a row, or the like, and the gold nanoparticles can be dissolved in an aqueous solution or a 5% dextrose solution.

 Compared with the prior art, the present invention has at least the following advantages:

 1. The aminopyrimidine-modified gold nanoparticle of the present invention is a 2-mercapto-4,6-diaminopyrimidine, 2-mercapto-4-aminopyrimidine which has no antibacterial activity per se and is often used as a pyrimidine prodrug. / or 2,4-diamino-6-mercaptopyrimidine modified to gold nanoparticles prepared, has excellent antibacterial activity.

 2. The aminopyrimidine modified gold nanoparticle of the invention has the advantages of small single particle size distribution, good particle dispersion in water (see Figures 2~5), and can be at 4 ° C or -20 ° C. After at least one year of storage, the lyophilized particles are still soluble in water. The 4-aminothiophenol-modified gold nanoparticles similar in structure to the aminopyrimidine reported in the literature (Fig. 7A, from Shi, W. et al, Colloids and Surfaces A: Physicochemical and Engineering Aspects 2004, 246, (1) -3), 109-113) and 6-mercaptopurine modified gold nanoparticles (Fig. 7B, from Selvaraj, V. et al, Electrochimica Acta 2006, 52, 1152-1160) are all agglomerated severely. The following is a detailed description of the invention:

The aminopyrimidine modified gold nanoparticles consist of gold nanoparticles and aminopyrimidine molecules bound thereto. The aminopyrimidine is selected from one or more of 2-mercapto-4,6-diaminopyrimidines (called DAPT), 2-mercapto-4-aminopyrimidine (called APT) and/or 2,4-diamino-6. - Mercaptopyrimidine (iDAPT), the chemical structure of the three aminopyrimidine molecules is shown in Figure 1. Single aminopyrimidine molecularly modified gold nanoparticles comprise 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles (called Au-DAPT), 2-mercapto-4-aminopyrimidine modified gold nanoparticles Au-APT) and 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticles (called Au-iDAPT); mixed aminopyrimidine-modified gold nanoparticles containing 2-mercapto-4,6-diaminopyrimidine Gold nanoparticles co-modified with 2-mercapto-4-aminopyrimidine (called Au DAPT/APT), 2-mercapto-4,6-diaminopyrimidine and 2,4-diamino-6-mercaptopyrimine Gold nanoparticles (called Au-DAPT/iDAPT), 2-mercapto-4-aminopyrimidine and 2,4-diamino-6-mercaptopyrim-modified gold nanoparticles (called Au-APT/iDAPT) and Gold nanoparticles (called Au-DAPT/APT/iDAPT) modified by the above three aminopyrimidine molecules. The transmission electron microscope (TEM) diagrams of Au DAPT, Au APT and AujDAPT are shown in Figures 2~5. This series of nanoparticles can be used as an antibacterial drug.

 Preferably, the method for preparing the above nanoparticles may comprise the following steps: (1) mixing the raw material chloroauric acid with an aminopyrimidine molecule and a surfactant to form a uniform solution; (2) reducing the above solution by using a reducing agent such as sodium borohydride or sodium ascorbate; The chloroauric acid forms aminopyrimidine-modified gold nanoparticles; (3) removing by-products such as salts and salts in the reaction system, and purifying the aminopyrimidine-modified gold nanometers from the exemplary embodiments of the embodiments include:

 (1) Prepare the reaction solution:

 Preparing a solution of chloroauric acid in water at a concentration of 1 to 10 mM, a solution of disulfoxide, decyl alcohol, ethanol or tetrahydrofuran;

 Prepare a solution of 1 to 10 mM aminopyrimidine in water, disulfoxide, decyl alcohol, ethanol or tetrahydrofuran, and add 0.2~1 ml of anhydrous acetic acid, propionic acid or hydrochloric acid (0.1N) and 0.02~0.1 ml Triton. X-100, Tween or polyethylene glycol to obtain a mixed solution containing aminopyrimidine;

 Formulate tetra-n-octyl ammonium bromide, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, dodecyltrimethylammonium chloride or 1~10 mM A solution of toluene or diphenylbenzene of a tetradecyltrimethylammonium chloride phase transfer catalyst.

 Preparing a solution of diterpene, decyl alcohol, ethanol or tetrahydrofuran at a concentration of 10 to 100 mM sodium borohydride;

 (2) Mixed chloroauric acid solution and aminopyrimidine solution:

 Mixing water of chloroauric acid prepared in step (1), disulfoxide, decyl alcohol, ethanol or tetrahydrofuran solution and a mixed solution containing aminopyrimidine at room temperature or below, and stirring for 10-30 minutes. Or mixing the aqueous solution of chloroauric acid prepared in the step (1) with an aqueous solution containing aminopyrimidine, and adding a solution of toluene or diphenylbenzene containing a phase transfer catalyst, and stirring for 30 to 60 minutes;

(3) Reduction reaction to prepare aminopyrimidine modified gold nanoparticles:

 Under rapid stirring, drip the sodium borohydride solution of sodium borohydride, decyl alcohol, ethanol or tetrahydrofuran in the step (1), and then drip in 5 minutes; then stir the stirring speed for 0.5 hour, and then fully react to obtain deep red. Solution

 (4) Purification of aminopyrimidine modified gold nanoparticles:

The solvent is removed under reduced pressure in the dark red solution formed in the above polar solvent, or a large amount of ethanol is added to the deep red solution formed in the non-polar solvent, and the solvent is removed after separation, and pure water is added. Dialysis was carried out in pure water for 48 hours with a dialysis bag having a molecular weight of 3 KDa or more, and water was changed every 2 hours; the solution after dialysis was filtered and sterilized by a 0.22 μηι microporous filter to obtain an aminopyrimidine-modified aqueous solution of gold nanoparticles, which was placed. Store at 4°C or store at -20 °C after lyophilization.

 The chloroauric acid comes from Shanghai Jiushan Chemical Co., Ltd., sodium borohydride, sodium ascorbate, polyethylene glycol (molecular weight 2000~5000), ethanol, toluene, diphenylbenzene, tetra-n-octyl ammonium bromide, tetrabutyl Ammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, dodecyltrimethylammonium chloride and tetradecyltrimethylammonium chloride from Sinopharm Group Beijing Chemical Reagent Company, 2-Mercapto-4,6-diaminopyrimidine from Merck, 2-mercapto-4-aminopyrimidine and 2,4-diamino-6-mercaptopyrimidine, disulfoxide, decyl alcohol, tetrahydrofuran, anhydrous acetic acid Triton X-100 and Tween (Tween 20, Tween 40, Tween 60 or Tween 80) were from Sigma.

 The particle size of the aminopyrimidine-modified gold nanoparticles was determined by a transmission electron microscope (Tecnai G2 20 S-TWIN transmission electron microscope, FEI, USA), and the ratio of gold to aminopyrimidine in the nanoparticles was determined by X-ray photoelectron energy. The instrument (ESCALab220I-XL, VG Scentific, UK) was used to determine the concentration of the aqueous nanoparticle solution (gold concentration) as determined by inductively coupled plasma atomic emission spectroscopy (ICP-OES, American PE).

 The present invention performs cytotoxicity test on the aminopyrimidine-modified gold nanoparticles provided, and proves that the aminopyrimidine-modified gold nanoparticles have no effect on the cell proliferation rate, that is, no cytotoxicity.

 The invention detects the antibacterial activity of the provided aminopyrimidine modified gold nanoparticles, and the specific specific detection methods include:

Five bacteria were cultured in broth culture medium: Escherichia coli, CGMCC1.2389, Gram-negative bacteria, dysentery bacillus, Salmonella typhi, Proteus or Vibrio cholerae in other Gram-negative bacteria Can be) Pseudomonas aeruginosa (CGMCC1.2387, Gram-negative bacteria), multi-drug resistant Escherichia coli (MDR E obtained from Beijing Tiantan Hospital, VITEK automatic bacterial separator for the isolation and identification of bacteria, clinical Separation No. 903657, drug-resistant Gram-negative bacteria, other drug-resistant bacteria such as other drug-resistant Escherichia coli isolated from clinical isolates, multidrug-resistant Pseudomonas aeruginosa (MDR ae g wwa, obtained from Beijing Tiantan Hospital, VITEK automatic bacterial separator for the isolation and identification of bacteria, clinical isolate No. 903624, drug-resistant Gram-negative bacteria and Staphylococcus epidermidis (CGMCC 1.2429, Gram-positive bacteria, with other Gram Pneumococcal, diphtheria and tetanus can be cultured for 8 to 16 hours in positive bacteria (S. epidermidis needs to be cultured for 16 hours, others need to be cultured) 8 to 10 hours), dilute the bacterial solution with fresh broth medium to make the OD value (600 nm) of the bacterial solution 0.1. Take 12 parts of 1.78 ml of broth culture medium and divide into 4 groups, each group at least 3 parts (that is, at least three parallels). Each group is added with different concentrations of aqueous drug solution (the drug can be aminopyrimidine modified gold nanoparticles, amino group). Pyrimidine or gentamicin, using pure water as a negative control) 200 μM each, The parallel doses of the same group were added at the same concentration, and 20 μΐ of the diluted E. coli bacteria solution was added to all 12 portions, cultured at 37 V, shaking at 200 rpm, and the turbidity of the bacterial solution was measured after 24 hours. The lowest concentration of the drug in the 4 groups was not turbid (OD value <0.05 at 600 nm), which is the minimum inhibitory concentration (MIC) of the drug against Escherichia coli.

 In another aspect, the present invention provides the use of the above aminopyrimidine-modified gold nanoparticles as a nano antibacterial agent, which is a drug resistant to Gram-negative bacteria, a drug resistant to Gram-positive bacteria, and/or resistant Drug-resistant clinical isolates of drugs. Wherein, preferably, the Gram-negative bacteria comprises Escherichia coli, Pseudomonas aeruginosa, Shigella, Salmonella typhi, Proteus or Vibrio cholerae; said Gram-positive bacteria include Staphylococcus epidermidis, pneumonia Diplococcus, diphtheria or tetanus; the drug-resistant clinical isolates include multi-drug resistant Gram-negative bacteria, such as multidrug-resistant E. coli and multidrug resistant patina Monocytogenes, etc.

 In still another aspect, the present invention provides a method for treating bacterial infection in vivo using the above aminopyrimidine modified gold nanoparticles as a nano antibacterial agent. Exemplary specific treatments include: intravenous injection, intramuscular injection, subcutaneous injection, intradermal injection, intraperitoneal injection or oral aminopyrimidine modified gold nanoparticles, E. coli or P. aeruginosa infection, gold nanoparticles, gold The solvent of the nanoparticles is water or 5% glucose, which is administered in a single administration, twice a day, once a day, three times in a row.

 The invention provides a method for synthesizing an aminopyrimidine which has a small particle size distribution, a small particle size distribution, good water dispersibility, can be stored at 4 ° C or -20 ° C for more than one year, and is non-toxic to human primary cells. Modified gold nanoparticles, synthetic methods and antibacterial uses, ie, 2-mercapto-4,6-diaminopyrimidine, 2-mercapto-4-aminopyrimidine and/or 2,4-Diamino-6-mercaptopyrimidine was modified (bound) onto gold nanoparticles to prepare aminopyrimidine-modified gold nanoparticles, and the aminopyrimidine-modified gold nanoparticles exhibited excellent antibacterial activity. The beneficial effects of the invention are:

 (1) 2-Mercapto-4,6-diaminopyrimidine, 2-mercapto-4-aminopyrimidine and/or 2,4-diamino-6-mercaptopyrimidine have no antibacterial activity per se, and have antibacterial properties after modification with gold nanoparticles. The effect, not the old drug modification, but belongs to the class I new drug, can be widely used in the preparation of antibacterial drugs, such as anti-gram-negative bacteria drugs, anti-gram-positive bacteria drugs or / and anti-multidrug resistance Clinical isolate drug;

 (2) The aminopyrimidine-modified gold nanoparticle of the present invention has a small particle size distribution, and the preparation method is simple and easy to preserve. DRAWINGS

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which: Figure 1 is 2-mercapto-4,6-diaminopyrimidine (called DAPT), 2-mercapto-4-aminopyrimidine (called APT) and 2,4-diamino-6-mercaptopyrimidine (iDAPT) Chemical structure.

 Figure 2 is a TEM image of 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles prepared in a polar solvent.

 Figure 3 is a 2-nonyl-4,6-diaminopyrimidine modified gold nanoparticle prepared in a non-polar solvent.

TEM image.

 Figure 4 is a TEM image of 2-mercapto-4-aminopyrimidine modified gold nanoparticles.

 Figure 5 is a TEM image of 2,4-diamino-6-mercaptopyrimidine modified gold nanoparticles.

 Figure 6 shows the effects of different concentrations of 2-indolyl-4,6-diaminopyrimidine modified gold nanoparticles on the proliferation of human umbilical vein endothelial cells.

 Figure 7 shows 4-aminothiophenol-modified gold nanoparticles (A) and 6-mercaptopurine-modified gold nanoparticles (B). The best way to implement the invention

 The present invention is further described in detail with reference to the preferred embodiments thereof. Example 1:

 The 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles are prepared in a polar solvent by the steps of: (1) preparing a reaction solution:

 Preparing a solution of 5 mM chlorosulfonic acid disulfoxide, which is prepared by dissolving 41.2 mg of chloroauric acid solid in 20 ml of disulfoxide.

 Prepare a solution of 2-mercapto-4,6-diaminopyrimidine disulfoxide at a concentration of 10 mM by adding 14.2 mg of 2-mercapto-4,6-diaminopyrimidine solid to 10 ml of sterol and adding 50 ΐ ΐ hydrochloric acid (0.1N) and 50 μΐ Triton X-100, sonicated to obtain a mixed solution containing 2-mercapto-4,6-diaminopyrimidine;

 Prepare a solution of sodium borohydride disulfoxide at a concentration of 60 mM, that is, 12 mg of sodium borohydride solid dissolved in 5 ml of disulfoxide.

 (2) Mixed chloroauric acid solution and aminopyrimidine solution:

 Mixing the chloroauric acid disulfoxide solution prepared in the step (1) with a mixed solution containing 2-mercapto-4,6-diaminopyrimidine, and stirring for 10 minutes;

(3) reduction reaction to obtain 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles: under rapid stirring, drip the sodium borohydride solution prepared in step (1), and drip within 2 minutes; Then, the stirring speed was lowered and stirred for 1 hour, and after fully reacting, a deep red solution was obtained; (4) Purification of 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles:

 Dioxin was removed under reduced pressure from the above dark red solution, pure water was added, and dialyzed in pure water for 48 hours with a dialysis bag having a molecular weight cut off of 3 kDa, and water was changed every 2 hours; the solution after dialysis was passed through a 0.22 μηι microporous filter. Filtration and sterilization to obtain a 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticle aqueous solution, stored at 4 ° C, or lyophilized - : C storage: , , , , ^ , , , , , . Inductively coupled plasma atomic emission spectroscopy (ICP-OES). A 10 μΐ nanoparticle aqueous solution was dropped on a 400 mesh carbon support membrane copper mesh, and after natural drying, the size and shape of the nanoparticles were observed by a transmission electron microscope (ΤΕΜ). The gold nanoparticles were washed three times with pure water, and after X-ray photoelectron spectroscopy (XPS), the molar ratio of the ligand molecule aminopyrimidine to the elemental gold in the nanoparticles was obtained.

 The aqueous solution containing the 2-mercapto-4,6-diaminopyrimidine-modified gold nanoparticles synthesized in this Example 1 is dark red, and it can be seen from Fig. 2 (ΤΕΜ图) that 2-mercapto-4,6-diaminopyrimidine can be seen. The modified gold nanoparticles have a particle size of 2.2 to 5.6 nm; the molar ratio of the 2-mercapto-4,6-diaminopyrimidine molecule to the gold element is 0.4:1. The above analysis and measurement results are shown in Table 1. Example 2:

 The 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles are prepared in a non-polar solvent, the steps of which are:

 (1) Prepare the reaction solution:

 Prepare a 1 mM aqueous solution of chloroauric acid, which is prepared by dissolving 4.1 mg of chloroauric acid solid in 10 ml of water;

 Prepare a 5 mM aqueous solution of 2-mercapto-4,6-diaminopyrimidine, add 7.1 mg of 2-mercapto-4,6-diaminopyrimidine solid to 10 ml of water, and add 50 μM hydrochloric acid (0.1N). And 50 μM polyethylene glycol (molecular weight 2000), sonicated to obtain a mixed solution containing 2-mercapto-4,6-diaminopyrimidine;

 A solution of 4 mM tetra-n-octyl ammonium bromide in toluene was prepared by adding 21.7 mg of tetra-n-octyl ammonium bromide solid to 20 ml of toluene and sonicating.

 Prepare a 20 mM sodium borohydride sterol solution, that is, 4 mg of sodium borohydride solid dissolved in 5 ml of sterol;

 (2) Mixing the chloroauric acid solution with the aminopyrimidine solution and transferring to the benzene solution:

Mixing the aqueous solution of chloroauric acid prepared in the step (1) with a mixed solution containing 2-mercapto-4,6-diaminopyrimidine, stirring for 10 minutes, adding a solution of toluene containing tetra-n-octyl ammonium bromide, and stirring for 40 minutes. , separating the two-phase solution, taking the upper non-polar solvent phase (ie, the benzene solution); (3) Reduction reaction to obtain 2-mercapto-4,6-diaminopyrimidine-modified gold nanoparticles: To the sodium borohydride solution prepared in the step (2), the sodium borohydride prepared in the step (1) is added dropwise under rapid stirring. The sterol solution is dripped within 5 minutes; then the stirring speed is lowered for 30 minutes, and after fully reacting, a deep red solution is obtained;

 (4) Purification of 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles:

 Add 30 ml of ethanol to the above dark red solution, and after flocculation, separate the floc, remove the ethanol under reduced pressure, add pure water, and dialyze in pure water for 24 hours with a dialysis bag with a molecular weight of 14 KDa, and change every 2 hours. Water; the dialyzed solution is sterilized by filtration through a 0.22 μηι microporous filter to obtain a 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticle aqueous solution, stored at 4 ° C, or lyophilized after -20 ° C storage. Inductively coupled plasma atomic emission spectroscopy (ICP-OES). A 10 μΐ nanoparticle aqueous solution was dropped on a 400 mesh carbon support membrane copper mesh, and after natural drying, the size and shape of the nanoparticles were observed by a transmission electron microscope (ΤΕΜ). The gold nanoparticles were washed three times with pure water, and after X-ray photoelectron spectroscopy (XPS), the molar ratio of the ligand molecule aminopyrimidine to the elemental gold in the nanoparticles was obtained.

 The aqueous solution containing the 2-mercapto-4,6-diaminopyrimidine-modified gold nanoparticles synthesized in this Example 2 is dark red, and it can be seen from Fig. 3 (ΤΕΜ图) that 2-mercapto-4,6-diaminopyrimidine can be seen. The modified gold nanoparticles have a particle size of 3.4 to 10.0 nm. Example 3:

 A gold nanoparticle containing 2-mercapto-4-aminopyrimidine is prepared by the steps of:

 (1) Prepare the reaction solution:

 Preparing a 5 mM chloroauric acid sterol solution, which is prepared by dissolving 41.2 mg of chloroauric acid solid in 20 ml of sterol;

 Prepare a solution of 2-mercapto-4-aminopyrimidinol at a concentration of 30 mM, adding 37.8 mg of 2-mercapto-4-aminopyrimidine solid to 10 ml of sterol, and adding 300 μΐ of anhydrous acetic acid and 50 μΐ of spit At a temperature of 20, a mixed solution containing 2-mercapto-4-aminopyrimidine is obtained;

 Prepare a 100 mM sodium borohydride sterol solution, that is, 20 mg of sodium borohydride solid dissolved in 5 ml of sterol;

 (2) Mixed chloroauric acid solution and aminopyrimidine solution:

 Mixing the chloroauric acid sterol solution prepared in the step (1) and the mixed solution containing 2-mercapto-4-aminopyrimidine in an ice bath condition, and stirring for 20 minutes;

(3) Reduction reaction to obtain 2-mercapto-4-aminopyrimidine modified gold nanoparticles: Under rapid stirring, the sodium borohydride sterol solution prepared in the step (1) is added dropwise, and the mixture is dropped within 2 minutes; then the stirring speed is lowered for 1 hour, and after fully reacting, a deep red solution is obtained;

 (4) Purification of 2-mercapto-4-aminopyrimidine modified gold nanoparticles:

 The above dark red solution was decompressed to remove sterol, pure water was added, and dialyzed in pure water for 48 hours with a dialysis bag having a molecular weight cut off of 3 KDa, and water was changed every 2 hours; the dialyzed solution was filtered through a 0.22 μηι microporous filter. Bacteria, an aqueous solution of 2-mercapto-4-aminopyrimidine modified gold nanoparticles was obtained, stored at 4 ° C, or stored at -20 ° C after lyophilization.禺 等 等 体 发射 发射 发射 a a a a a a a a a a a a a. The nano-particles were dissolved in a 400-mesh carbon support film copper mesh. After drying, the size and shape of the nanoparticles were observed by transmission electron microscopy (TEM). The gold nanoparticles are washed three times with pure water, and after X-ray photoelectron spectroscopy (XPS), the molar ratio of the ligand molecules to the elemental gold in the nanoparticles is obtained.

 The aqueous solution containing the 2-mercapto-4-aminopyrimidine-modified gold nanoparticles synthesized in this example is dark red, and the particles of 2-mercapto-4-aminopyrimidine-modified gold nanoparticles can be seen from FIG. 4 (TEM image). The diameter is 1.5 to 6.0 nm; the molar ratio of 2-nonyl-4-aminopyrimidine to gold is 0.2:1. The above analysis and measurement results are shown in Table 1. Example 4:

 Preparation of 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticles, the steps of which are:

 (1) Prepare the reaction solution:

 Preparing a solution of 5 mM chloroauric acid tetrahydrofuran, which is prepared by dissolving 41.2 mg of chloroauric acid solid in 20 ml of tetrahydrofuran;

 A solution of 2,4-diamino-6-mercaptopyrimidine tetrahydrofuran at a concentration of 100 mM was prepared by adding 142 mg of 2,4-diamino-6-mercaptopyrimidine solid to 10 ml of tetrahydrofuran and adding 400 μM of anhydrous acetic acid. And 80 μM Tween 80 to obtain a mixed solution containing 2,4-diamino-6-mercaptopyrimidine;

 Prepare a solution of sodium ascorbate tetrahydrofuran at a concentration of 100 mM, that is, 99 mg of sodium ascorbate solid dissolved in 5 ml of tetrahydrofuran;

 (2) Mixed chloroauric acid solution and aminopyrimidine solution:

 Mixing the chloroauric acid tetrahydrofuran solution prepared in the step (1) with the mixed solution containing 2,4-diamino-6-mercaptopyrimidine, and stirring for 10 minutes;

(3) Reduction reaction to obtain 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticles: Under rapid stirring, the sodium ascorbate tetrahydrofuran solution prepared in the step (1) is added dropwise, and the solution is dropped within 2 minutes; Stirring at a stirring speed for 2 hours, and obtaining a deep reddish purple solution after sufficient reaction; (4) Purification of 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticles:

 The above dark red solution was decompressed to remove tetrahydrofuran, and pure water was added thereto, and dialyzed in pure water for 48 hours with a dialysis bag having a molecular weight cut off of 3 KDa, and water was changed every 2 hours; the dialyzed solution was filtered and sterilized by a 0.22 μηι microporous filter. An aqueous solution of 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticles was obtained, stored at 4 ° C, or stored at -20 ° C after lyophilization.

 The concentration of the 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticle aqueous solution (elemental gold) can be measured by an inductively coupled plasma atomic emission spectroscopy (ICP-OES). A 10 μΐ nanoparticle aqueous solution was dropped on a 400 mesh carbon support membrane copper mesh, and after natural drying, the size and shape of the nanoparticles were observed by a transmission electron microscope (ΤΕΜ). The gold nanoparticles are washed three times with pure water, and after X-ray photoelectron spectroscopy (XPS), the molar ratio of the ligand molecules to the elemental gold in the nanoparticles is obtained.

 The aqueous solution containing the 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticles synthesized in this Example 3 is dark red, and 2,4-diamino-6-mercaptopyrimidine can be seen from Fig. 5 (ΤΕΜ图). The modified gold nanoparticles have a particle size of 3.5 to 10.0 nm, and the molar ratio of the 2,4-diamino-6-mercaptopyrimidine molecule to the gold element is 0.3:1. The above analysis and measurement results are shown in Table 1. Example 5

Preparation of 2-mercapto-4,6-diaminopyrimidine ¹ 3⁄4/2-mercapto-4-aminopyrimidine modified gold nanoparticles, the steps of which are:

 (1) Prepare the reaction solution:

 Preparing a solution of 5 mM chloroauric acid tetrahydrofuran, which is prepared by dissolving 41.2 mg of chloroauric acid solid in 20 ml of tetrahydrofuran;

 Prepare a 10 mM solution of pyrimidine in tetrahydrofuran, add 71 mg of 2-mercapto-4,6-diaminopyrimidine and 64 mg of 2-mercapto-4-aminopyrimidine solid to 10 ml of tetrahydrofuran, and add 400 Μΐ anhydrous acetic acid and 100 μΐ polyethylene glycol (molecular weight 5000) to obtain a mixed solution containing 2-mercapto-4,6-diaminopyrimidine and 2-mercapto-4-aminopyrimidine;

 Preparing a solution of 100 mM sodium borohydride tetrahydrofuran, that is, 20 mg of sodium borohydride solid dissolved in 5 ml of tetrahydrofuran;

 (2) Mixed chloroauric acid solution and aminopyrimidine solution:

 Mixing the chloroauric acid tetrahydrofuran solution prepared in the step (1) with a mixed solution containing 2-mercapto-4,6-diaminopyrimidine/2-mercapto-4-aminopyrimidine, and stirring for 30 minutes;

(3) Reduction reaction to obtain 2,4-diamino-6-mercaptopyrimidine-modified gold nanoparticles: After rapid stirring, the sodium borohydride tetrahydrofuran solution prepared in the step (1) is added dropwise, and the mixture is dropped within 2 minutes; Stirring at a reduced stirring speed for 2 hours, and obtaining a deep reddish purple solution after sufficient reaction; (4) Purification of 2-mercapto-4,6-diaminopyrimidine/2-mercapto-4-aminopyrimidine modified gold nanoparticles:

 The above dark red solution was decompressed to remove tetrahydrofuran, and pure water was added thereto, and dialyzed in pure water for 48 hours with a dialysis bag having a molecular weight cut off of 3 KDa, and water was changed every 2 hours; the dialyzed solution was filtered and sterilized by a 0.22 μηι microporous filter. An aqueous solution of gold nanoparticles modified with 2-mercapto-4,6-diaminopyrimidine/2-mercapto-4-aminopyrimidine is obtained, stored at 4 ° C, or stored at -20 ° C after lyophilization.

 The concentration of 2-indolyl-4,6-diaminopyrimidine/2-mercapto-4-aminopyrimidine-modified aqueous gold nanoparticles (elemental gold) can be measured by inductively coupled plasma atomic emission spectroscopy (ICP-OES). A 10 μL aqueous solution of the nanoparticles was dropped on a 400-mesh carbon support film copper mesh, and after natural drying, the size and shape of the nanoparticles were observed by a transmission electron microscope (ΤΕΜ). The gold nanoparticles are washed three times with pure water, and after X-ray photoelectron spectroscopy (XPS), the molar ratio of the ligand molecules to the elemental gold in the nanoparticles is obtained.

An aqueous solution containing ^{2-mercapto-4,6-diamino-pyrimidin-1} ¾ / 2- mercapto-4-amino pyrimidine synthesis of Example 5 of the present embodiment is modified gold particles is deep red, a particle size of 2.0 ~ 6.0 nm. Example 6

Cytotoxicity assay of 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles of the present invention: The second generation of human umbilical vein endothelial cells with good growth state was inoculated into 96-well plates according to Ι ΙΟ ΙΟ ⁴ cells/well. After adhering to the wall, 200 μM of M199 medium containing 100 g/ml gold nanoparticles was added in the second row, and M199 medium 200 containing 10 and 50 g/ml gold nanoparticles was sequentially added to the third and fourth rows. Μΐ, add six holes per line. In the fifth row, 200 μl of M199 medium containing no nanoparticles was added. After 24 hours of culture, the color was developed by CCK-8 kit for 4 hours, and the absorbance at 450 nm was read on a microplate reader at 600 nm. The absorbance at various concentrations of nanoparticles was counted and the histogram was made. , Figure 6 shows that the aqueous solution of gold nanoparticles containing 2-mercapto-4,6-diaminopyrimidine modified has no effect on cell proliferation rate, ie no cytotoxicity, at concentrations up to 100 g/ml.

 The above cytotoxicity test uses the 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles prepared in Example 1, and other aminopyrimidine modified gold nanoparticles prepared by the preparation method provided by the present invention can also be used. Perform a cytotoxicity test. Example 7

 Detection of the activity of Gram-negative bacteria against the aminopyrimidine-modified gold nanoparticles of the present invention:

Escherichia coli (Escherichia col " CGMCC 1.2389 ) was cultured in broth medium for 8-10 hours, and the OD value (600 nm) of the diluted solution was 0.1 with fresh broth medium. 12 parts 1.78 Ml broth medium, divided into 4 groups, 3 parts each (ie three parallel), 1-4 groups were added 4, 6, 8 and 10 g/ml of 2-mercapto-4,6-diaminopyrimidine The modified gold nanoparticles aqueous solution was 200 μM each, and the three groups in the same group were added at the same concentration. Then, 20 μM of the diluted E. coli bacteria solution was added to all 12 portions, and cultured at 37 ° C and a shaking rate of 200 rpm. The turbidity of the bacterial liquid was measured after 24 hours, and the lowest nanoparticle concentration in the 4 groups was not turbid (OD value <0.05 at 600 nm), and the minimum nanoparticle concentration was 6 g/ml, that is, 2-mercapto-4,6-diaminopyrimidine modified The minimum inhibitory concentration (MIC) of gold nanoparticles to E. coli was 6 g/ml.

 The above antibacterial activity was detected by using the 2-mercapto-4,6-diaminopyrimidine-modified gold nanoparticle prepared in Example 1, and the 2-mercapto-4,6-diaminopyrimidine preparation prepared in Example 2 was used in the same manner. Gold nanoparticles, 2-mercapto-4-aminopyrimidine modified gold nanoparticles prepared in Example 3, 2,4-diamino-6-mercaptopyrimidine modified gold nanoparticles prepared in Example 4, and Preparation of Example 5 The 2-n-based 4,6-diaminopyrimidine/2-mercapto-4-aminopyrimidine-modified gold nanoparticles were also tested for anti-E. coli activity, and the results showed that the above aminopyrimidine-modified gold nanoparticle aqueous solution also had Bacteriostatic effect.

 The results of the above-mentioned aminopyrimidine-modified gold nanoparticles against Gram-negative bacteria activity (minimum inhibitory concentration MIC) are shown in Table 1. Example 8

 Detection of the activity of Gram-positive bacteria against the aminopyrimidine-modified gold nanoparticles of the present invention:

 Staphylococcus epidermidis (CGMCC 1.2429) was cultured in broth for 16 hours, and the OD value (600 nm) of the diluted solution was 0.1 with fresh broth medium. Take 12 parts of 1.78 ml of broth culture medium and divide into 4 groups of 3 parts (three parallels), and groups 1-4 add 4, 8 , 16 and 32 g/ml of 2-mercapto-4,6 respectively. - 200 μM of diaminopyrimidine-modified gold nanoparticle solution, the same concentration of the three drugs in the same group, and then add 20 μM of diluted S. epidermidis solution to all 12 parts, 37 ° C, shaking The culture was carried out at a rate of 200 rpm, and the turbidity of the bacterial liquid was measured after 24 hours. The lowest nanoparticle concentration in the four groups was not turbid (OD value <0.05 at 600 nm), and the minimum nanoparticle concentration was 32 g/ml, that is, 2-mercapto-4,6- The minimum inhibitory concentration (MIC) of diaminopyrimidine modified gold nanoparticles against S. epidermidis was 32 g/ml.

 The results of the anti-Gram-positive bacteria activity (minimum inhibitory concentration MIC) of the 2-mercapto-4,6-diaminopyrimidine-modified gold nanoparticles are shown in Table 1. Example 9

Detection of antibacterial activity of aqueous solution of aminopyrimidine: Escherichia col CGMCC 1.2389 was cultured in broth medium for 8-10 hours, and the OD value (600 nm) of the diluted solution was 0.1 with fresh broth medium. Take 9 parts of 1.78 ml of broth culture medium, divide into 3 groups, 3 parts each (ie three parallel), and add 1-3 groups of 10, 100 and 1000 g/ml 2-mercapto-4,6-two The aqueous solution of aminopyrimidine was 200 μM each, and the three drugs in the same group were added at the same concentration. Then, 20 μM of the diluted E. coli bacteria solution was added to all 9 parts, and cultured at 37 ° C, shaking rate of 200 rpm, 24 hours. After that, the turbidity of the bacterial liquid was measured. All three groups of bacteria were turbid (OD values at 1.6 nm were 1.62 ± 0.14, 1.76 ± 0.11 and 1.90 ± 0.11, respectively), so the minimum inhibitory concentration (MIC) of 2-mercapto-4,6-diaminopyrimidine against Escherichia coli More than 1000 g/ml, no antibacterial activity is considered.

 The above antibacterial activity was tested by using the pyrimidine ligand used in the preparation of the 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticle aqueous solution of Example 1, and the same example was used to prepare the corresponding aminopyrimidine modified gold nanoparticle. The aminopyrimidine ligand used in the granules was also tested for antibacterial activity. The results showed that the minimum inhibitory concentration of the above aminopyrimidine ligands was more than 1000 g/ml, and no antibacterial activity was considered.

 The results of the above-mentioned aminopyrimidine ligand antibacterial activity test are collectively shown in Table 1. Example 10

 Detection of antibacterial activity of gentamicin aqueous solution:

 Escherichia coli (Escherichia col " CGMCC 1.2389 ) was cultured in broth medium for 8-10 hours, and the OD value (600 nm) of the diluted liquid solution was 0.1 with fresh broth medium. 12 parts of 1.78 ml of broth was cultured. Base, divided into 4 groups, each group of 3 (ie three parallel), 1~4 groups were added 0.4, 0.8, 1 and 2 g / ml of gentamicin aqueous solution 200μ1 each, three in the same group The concentration of the drug was the same, and 20 μl of the diluted E. coli broth was added to all 12 portions, and cultured at 37 ° C, shaking rate of 200 rpm, and the turbidity of the broth (OD value at 600 nm) was measured 24 hours later. The minimum drug concentration of the turbid liquid (OD value <0.05 at 600 nm) is 1 g/ml, that is, the minimum inhibitory concentration (MIC) of gentamicin to Escherichia coli is 1 g/ml. The strain is Escherichia coli, and the antibacterial activity of P. aeruginosa, multidrug-resistant Escherichia coli, multidrug-resistant Pseudomonas aeruginosa and Gram-positive bacteria can be detected by the same method.

The properties of the aminopyrimidine modified gold nanoparticles and the inhibition test results are shown in Table 1. "-" in the table indicates unnecessary or untested items. Table 1

实施例 11:

Example 11

 Treatment of mice infected with E. coli:

 Escherichia coli was cultured overnight, diluted 100-fold with a medium, and diluted 10 times with a medium containing 0.5% of highly active dry yeast. Take 50 SPF-grade 4-6 weeks ICR mice, male and female, divided into 5 groups, 10 in each group, 0.5 ml of E. coli culture medium containing high activity yeast, and then intravenously give four groups of mice respectively. Injection doses of 0.001, 0.005, 0.05, 0.5 mg/kg of 2-mercapto-4,6-diaminopyrimidine modified gold nanoparticles were applied once, and the fifth group was the untreated control group. Survival rate. The results showed that all the mice in the control group died, and the gold nanoparticle treatment group showed a therapeutic effect with a cure rate of 20 to 60%.

 The above bacterial infection treatment method adopts the preparation of 2-mercapto-4,6-diaminopyrimidine-modified gold nanoparticle aqueous solution in Example 1, and similarly, the aminopyrimidine-modified gold nanoparticle prepared by using other examples has a therapeutic effect. At a dose of 0.001 to 1 mg/kg, the cure rate is 10 to 60%.

 The above bacterial infection treatment method uses an aqueous solution of gold nanoparticles, and a 5% glucose solution using gold nanoparticles also has a cure rate of 10% or more.

 The above-mentioned bacterial infection treatment method is administered intravenously, and other methods of intramuscular injection, subcutaneous injection, intradermal injection, intraperitoneal injection or oral administration have a cure rate of more than 10%.

 The above-mentioned bacterial infection treatment method adopts a single administration method, and other administration methods are administered twice a day, and once a day, three consecutive administrations also have a cure rate of more than 10%.

The above-mentioned bacterial infection treatment method is Escherichia coli, and the same method can be used for Pseudomonas aeruginosa, multidrug-resistant Escherichia coli, multidrug-resistant Pseudomonas aeruginosa and Gram-positive bacteria. Treatment of infection in the body. It can be concluded that: the invention modifies aminopyrimidine on gold nanoparticles, can exhibit antibacterial activity of aminopyrimidine which does not have antibacterial activity, and can be applied to prepare anti-gram-negative bacteria and anti-gram-positive bacteria Drug or/and anti-multidrug resistant clinical isolates; and no fine-package toxicity.

Claims

Rights request  A gold nanoparticle characterized in that the surface of the gold nanoparticle is modified by an aminopyrimidine molecule. 2. The gold nanoparticle according to claim 1, wherein the aminopyrimidine molecule modified on the surface of the gold nanoparticle is one or more 2-mercapto-4,6-diaminopyrimidine, 2-fluorenyl group 4-aminopyrimidine and/or 2,4-diamino-6-mercaptopyrimidine. The aminopyrimidine modified gold nanoparticle according to claim 1 or 2, wherein the average particle diameter of the particles ranges from 1.0 to 10.0 nm, and the molar ratio of the aminopyrimidine molecule to the gold element in the nanoparticle It is 0.1:1 ~0.9:1. 4. A method of preparing aminopyrimidine modified gold nanoparticles according to any one of claims 1 to 3, the steps of which comprise:  (1) dissolving and mixing chloroauric acid and aminopyrimidine to form a mixed solution;  (2) reducing agent such as sodium borohydride or sodium ascorbate to reduce chloroauric acid in the above mixed solution to form aminopyrimidine-modified gold nanoparticles;  (3) Purification of aminopyrimidine-modified gold nanoparticles. The preparation method according to claim 4, wherein the molar ratio of the chloroauric acid to the aminopyrimidine molecule in the mixed solution is 1:1 to 1:10; the molar ratio of the chloroauric acid to the reducing agent It is 1:1~1:10. The preparation method according to claim 4 or 5, wherein the chloroauric acid, the aminopyrimidine and the reducing agent are dissolved in a polar solvent or a non-polar solvent, preferably, the polar solvent is selected. From water, disulfoxide, decyl alcohol, ethanol and/or tetrahydrofuran, the non-polar solvent is selected from the group consisting of toluene and/or diphenylbenzene. The preparation method according to any one of claims 4 to 6, wherein the mixed solution contains an organic acid or an inorganic acid, preferably, acetic acid, propionic acid or hydrochloric acid; further preferably, an acid The volume content in the mixed solution is from 0.5% to 10%. The preparation method according to any one of claims 4 to 7, wherein the mixed solution contains a nonionic surfactant; preferably, the nonionic surfactant contained is Triton X-100, Tween and polyethylene glycol; further preferably, the volume content of the nonionic surfactant in the mixed solution is from 1% to 10%. The preparation method according to any one of claims 4 to 8, wherein the non-polar solvent further comprises a phase transfer catalyst, and the phase transfer catalyst is preferably tetra-n-octyl ammonium bromide. Tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, phase transfer catalyst The molar concentration in the non-polar solvent is from 1 to 10 mM. The preparation method according to any one of claims 4 to 9, wherein the reducing time of the reducing agent for reducing chloroauric acid is 0.5 hours or more, and the reaction temperature is below room temperature, preferably from room temperature to zero degrees Celsius. Between the room temperature and zero degrees Celsius; further preferably, the reaction time is 0.5 to 3 hours. An antibacterial agent comprising the aminopyrimidine-modified gold nanoparticle according to any one of claims 1 to 3. The antibacterial agent according to claim 11, wherein the antibacterial agent is selected from the group consisting of one or more anti-Gram-negative bacteria drugs, anti-Gram-positive bacteria drugs and/or anti-drug resistant drugs. a pharmaceutical clinical isolate drug; preferably, the Gram-negative bacteria comprise Escherichia coli, Pseudomonas aeruginosa, Shigella dysenteria, Salmonella typhi, Proteus and Cholera, the Gram-positive bacteria comprising epidermal grapes Coccus, pneumococci, diphtheria and tetanus, the multidrug resistant clinical isolate comprises multidrug resistant E. coli and Pseudomonas aeruginosa. 13. The use of the gold nanoparticles according to any one of claims 1 to 3 for the preparation of an antibacterial agent; preferably, the antibacterial agent is selected from the group consisting of one or more anti-gram-negative bacteria drugs, resistant to Gram Positive drug and/or anti-multidrug resistant clinical isolate; further preferably, the Gram-negative bacteria comprise Escherichia coli, Pseudomonas aeruginosa, Shigella, Salmonella typhi, Proteus and Cholera, the Gram-positive bacteria comprising Staphylococcus epidermidis, Pneumococci, Diphtheria and Tetanus, the multi-drug resistant clinical isolate comprising multi-drug resistant E. coli and patina Cytobacteria. 14. A method of treating a disease caused by a bacterium and a disease, disorder or condition associated therewith, characterized in that the method comprises administering a therapeutically effective amount after bacterial infection in a mammal The aminopyrimidine modified gold nanoparticle of any one of claims 1 to 3 or the antibacterial agent of claims 11-12. 15. The method of claim 14 wherein the aminopyrimidine modified gold nanoparticles are administered in a form dissolved in water or a 5% dextrose solution;  Preferably, it is administered intravenously, intramuscularly, subcutaneously, intradermally, intraperitoneally or orally.