DE2159363A1 - Antimicrobial nitrofurans - useful eg as feed additives - Google Patents

Abstract

Antimicrobial agents contain >=1 nitrofuran deriv. of formula (I): (where R1 is alkyl and R2 is H, alkyl, alkoxy, NO2 or halogen). (I) are antimicrobials (esp. antibacterials) with considerably higher activity and lower toxicity than similar cpds., and can be used in human and veterinary medicine for the treatment of internal and external infections. (I) also have growth-promoting and feed utilization-improving props., for which purpose they are pref. administered to animals in the fodder and/or the drinking water.

Description

Antimicrobial Agents The present invention relates to use of widely known nitrofuran derivatives as antimicrobial agents, in particular as antibacterial agents as well as feed additives.

It has already become known that certain indole nitrogen unsubstituted and 3- (5-nitro-2-furfurylidene) oxindoles acylated on the indole nitrogen have an antibacterial effect (cf. Belgian patent 570 478).

However, they show various disadvantages such as a relatively high toxicity.

It has been found that the largely known nitrofuran derivatives of the formula (I) in which R1 stands for an alkyl radical and R2 stands for hydrogen, an alkyl group, an alkoxy group, a nitro group or halogen, have strong antibacterial properties and properties that allow their use as feed additive.

Surprisingly, the nitrofuran derivatives of the formula I show a significantly higher efficacy and significantly lower toxicity than that from Nitrofuran derivatives known from the prior art (e.g. those of the Belgian patent specification 570 478). The active ingredients according to the invention thus represent an enrichment of technology represent.

The nitrofuran derivatives to be used according to the invention are through Formula I is precisely defined and in some cases already known (see Canadian Journal of Chemistry, Vol. 46, No. 13, 2189-2194).

In formula I, the alkyl radicals R1 and R2 are preferably alkyl radicals with 1 to 4, in particular with 1 or 2 carbon atoms. They are exemplary Methyl, ethyl, n.- and i.-propyl and n.-, i.- and t.-butyl radicals called. Quite R.sup.1 particularly preferably represents the methyl radical.

In formula I, the alkoxy group R² preferably represents an alkoxy group with 1 to 4, in particular with 1 or 2 carbon atoms. They are exemplary Methoxy, ethoxy, n.- and i.-propyloxy and n.-, i.- and t.-butyloxy radicals are called.

Halogen R2 means fluorine, chlorine, bromine and iodine, preferably fluorine, Chlorine and bromine, especially chlorine and bromine.

R2 particularly preferably represents hydrogen.

Examples of the active ingredients to be used according to the invention are named: 3- (5'-Nitro-2'-furfurylidene) -N-methyl-oxindole 3- (5'-Nitro-2'-furfurylidene) -N-ethyl-oxindole 3- (5'-Nitro-2'-furfurylidene) -N-isobutyl-oxindole 3- (5'-Nitro-2t-furfurylidene) -7-methyl-N-methyl-oxindole 3- (5'-nitro-2'-furfurylidene) -7-chloro-N-ethyl-oxindoi 3- (5'-nitro-2'-furfurylidene) -6-methyl-N-ethyl exindole 3- (5-nitro-2'-furfurylidene) -5-methyl-N-methyl-oxindole 3- (5'-nitro-2'-furfurylidene) -5-methyl-N-ethyl-oxindole Some of the active ingredients to be used according to the invention are new, but they can can be produced in a simple manner by known methods.

They are obtained, for example, if an oxindole of the formula (II) in which R1 and R2 have the meaning given, with 5-nitrofurfural of the formula (iii) condensed in glacial acetic acid or acetic anhydride as the solvent at temperatures from about 80 to about 150 ° C., preferably at temperatures between 100 and 140 ° C., in particular at the boiling point of the reaction mixture, the starting compounds of the formulas II and III preferably being used in molar amounts. The active ingredients of the formula I to be used according to the invention are isolated and purified by known methods, for example by suctioning off the precipitated crystals and, for example, by recrystallization

from methyl glycol.

The oxindoles to be used as starting compounds are known, or obtainable by known methods.

The active ingredients of formula I have strong antimicrobial in particular antibacterial and antifungal effects.

Their effectiveness extends to gram-positive and gram-negative Bacteria, with the following bacterial families, bacterial genera and Species of bacteria may be mentioned: Enterobacteriaceae, e.g. Escherichia, in particular Escherichia coli, Klebsiella, in particular Klebsiella pneumoniae, Proteus, in particular Proteus vulgaris, Proteus mirabilis, Proteus morganii, Proteus rettgeri and Salmonella, in particular Salmonella typhi murium, Salmonella enteritidis; from the family of Pseudomonadeceae, e.g. Pseudomonas aeruginosa: from the family of the Micrococcaceae, e.g., Staphylococcus aureus, Staphylococcus epidermidis; from the family of the Streptococcaceae, z.3. Streptococcus pyogenes, Streptococcus faecalis (Enterococcus); from the family of the Mycoplasmataceae, e.g. Mycopolasma pneumoniae, Macoplasma arthritidis.

Fungi are yeasts, molds, dermatophytes and dimorphic fungi called.

Examples are: Candida, e.g. Candida albicans, Cryptococcus, Aspergillus, e.g. Aspergillus niger, Trichophyton, e.g. Trichophyton mentagrophytes, Penicillium comune, Microsporon, e.g.

Microsporon felinum. Furthermore, as pathogens are still exemplary Saprolegnia parasitica and Aeromonas liquefaciens are listed.

The excellent and broad antibacterial effectiveness of the nitrofuran derivatives of the formula I enables their use both in human and in veterinary medicine, with she but also for the prophylaxis of bacterial infections can be used to treat bacterial infections that have already occurred.

Indications for human medicine are internal and external infections such as infections of the oral cavity, vagina, pyoderma, abscesses, Wound enlargements and intestinal infections, especially intestinal infections, called.

For the veterinary field, external and internal infections represent e.g. pyoderma, abscesses, wound ulcers, intestinal infections, intrauterine Infections (especially with or after Retentio secundinarum) and mastitis of the Cattle are typical indications. In principle, everyone can use the new means higher animals, especially young or adult pets, see B. Poultry, like Chicks, pigeons, cats, dogs, rabbits, sheep, pigs, cows and cattle are treated will.

The present invention 'includes pharmaceutical preparations, which in addition to non-toxic, inert pharmaceutically suitable carriers one or contain several compounds of the formula I or those of one or more compounds of formula I exist as well as processes for the production of these preparations.

The present invention also includes pharmaceutical preparations in dosage units. This means that the preparations in the form of individual parts e.g. tablets, coated tablets, capsules, pills, suppositories and ampoules are present, whose active ingredient content corresponds to a fraction or a multiple of a single dose. The dosage units can be, for example, 1, 2, 3 or 4 single doses or 1/2, 1/3 or Contain 1/4 of a single dose. A single dose preferably contains the amount Active ingredient that is administered in one application and which is usually a corresponds to whole, half or a third or a quarter of a daily dose.

Among non-toxic, inert pharmaceutically acceptable carriers are solid, semi-solid or liquid thinners, fillers and formulation auxiliaries of any kind to understand.

Preferred pharmaceutical preparations are tablets, coated tablets, Capsules, pills, granules, solutions, suspensions and emulsions, pastes, ointments, Called gels, creams, lotions, powders and sprays.

Tablets, coated tablets, capsules, pills and granules can be the or contain the active ingredients in addition to the usual carriers; such as (a) fillers and extenders, e.g. starches, milk sugar, cane sugar, glucose, mannitol and silicic acid, (b) binders, e.g. carboxymethyl cellulose, alginates, gelatine, polyvinylpyrrolidone, (c) humectants, zeB. Glycerin, (d) disintegrants, e.g. agar-agar, calcium carbonate and sodium bicarbonate (e) dissolution retarders, e.g., paraffin; and (f) absorption accelerators, e.g. B. quaternary Ammonium compounds, (g) wetting agents, see B. Cetyl alcohol, glycerol monostearate, (h) Adsorbents, e.g., kaolin and bentonite, and (i) lubricants, e.g. B.

Talc, calcium and magnesium stearate and solid polyethylene glycols or mixtures of the substances listed under (a) - (i).

The tablets, coated tablets, capsules, pills and granules can be used with the customary coatings and shells, optionally containing opacifying agents be and also be composed so that they only or the active ingredient or preferably in a certain part of the intestinal tract, possibly delayed using e.g. polymer substances and waxes as embedding compounds can be.

The active ingredient (s) can optionally be combined with one or more of the above-mentioned carriers are also in microencapsulated form.

Ointments, snaps, creams and gels can be used in addition to the active ingredient or ingredients contain the usual carriers, e.g. B. animal and vegetable fats, waxes, Paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, Silicic acid, talc and zinc oxide or mixtures of these substances, powders and sprays can be used contain the usual carrier substances in addition to the active ingredient (s), e.g. lactose, Talc, silica, aluminum hydroxide, calcium silicate and polyamide powder or mixtures these substances. Sprays can also use the usual propellants, e.g. chlorofluorocarbons contain.

Solutions and emulsions can be used in addition to the active substance or substances common carriers, such as solvents, solubilizers and emulsifiers, e.g. water, Ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, Propylene glycol, 1,5-butylene glycol, dimethylformamide, oils, especially cottonseed oil, Peanut oil, corn oil, olive oil, castor oil and sesame oil, glycerine, glycerine formal, Tetrahydro furfuryl alcohol, polyethylene glycols and fatty acid esters des Sorbitans or mixtures of these substances.

In addition to the active ingredient (s), suspensions can include the usual carriers, such as liquid diluents, e.g.

Water, ethyl alcohol, propylene glycol, suspending agents e.g.

ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth or mixtures of these substances.

The stated forms of formulation can also contain colorants and preservatives as well as additives that improve smell and taste, e.g. peppermint oil and eucalyptus oil and sweeteners such as saccharin.

The therapeutically active compounds are intended to be in those listed above pharmaceutical preparations preferably in a concentration of about 0.1 to 99.5, preferably from about 0.5 to 95 percent by weight of the total mixture be.

The pharmaceutical preparations listed above can except Compounds of the formula I also contain other active pharmaceutical ingredients.

The manufacture of the pharmaceutical preparations listed above takes place in the usual way by known methods, such as by mixing the or the Active ingredients with the carrier or carriers and, if appropriate, subsequent transfer the mixture into the desired form, e.g. in tablets, with the help of a tableting machine.

The present invention also includes the use of the compounds of the formula I and of pharmaceutical preparations that contain one or more compounds of formula I, in human and veterinary medicine for prevention, improvement and / or healing of the diseases listed above.

The active ingredients or the pharmaceutical preparations can be used locally, administered orally and intraperitoneally, preferably orally and locally.

In general it has been used in both buman and veterinary medicine Proven to be advantageous, the active ingredient (s) when administered orally in amounts of about 1 to about 200, preferably 20 to 100, in particular 30 to 80 mg / kg of body weight every 24 hours, if necessary in the form of several, preferably 2 individual doses to achieve this to administer the desired results. A single gift contains the one or the other Active ingredients, preferably in amounts of about 0.5 to about 100, preferably 10 to 50, in particular 15 to 40 mg / kg body weight.

Similar dosages can be used for intraperitoneal treatment come into use. In mastitis therapy in cattle, e.g. 10 to about 1000, preferably 20 to 500, in particular 40 to 150 mg of active ingredient per udder quarter applied.

For a local application, preparations come into question, such as 0.01 to about 10, preferably 0.05 to 5, in particular 0.2 to 2 percent by weight Contain active ingredient.

However, it may be necessary to deviate from the dosages mentioned and depending on the type and body weight the to treating object the nature and severity of the disease, the nature of the preparation and the application of the drug and the period or interval within to which the administration takes place. So in some cases it may be sufficient get by with less than the above amount of active ingredient, while in others Cases the amount of active ingredient listed above must be exceeded. The definition the required optimal dosage and type of application of the active ingredients can easily be done by any skilled person on the basis of their specialist knowledge.

The compounds of formula I can also be used as feed additive to promote growth and improve feed evaluation in animal husbandry, especially when rearing young cattle, such as calves, piglets, chicks, turkeys and in the keeping of beef cattle, such as B. cattle, pigs, etc. can be used.

The application of the active ingredient or ingredients is preferably carried out for this purpose over the food and / or drinking water.

The active ingredients can also be used in feed concentrates, as well as in vitamin and / or preparations containing mineral salts can be used.

The new compounds are added to the feed or the drinking water in one Concentration of about 0.1 to about 1000, preferably 1 to 200, in particular 20 added up to 100 ppm.

Mixing with the feed, possibly in the form of a premix (e.g. active ingredient and wheat meal) or the feed concentrates and the rest Feed preparations are made according to the usual methods.

The strong antimicrobial activity of the compounds according to the invention of the formula I can be seen from the following in vitro and in vivo tests: 1. In vitro experiments (Tables t to 3): The test of the minimum inhibitory concentrations (MIC) of the gram-positive and gram-negative bacteria took place in the small medium (meat extract, Peptone, dextrose, pH 7.1) at an incubation temperature of 3700 and an incubation time of 24 hours, whereby the number of germs was 104 germs per ml of nutrient medium.

The MIC values for mycoplasma were determined in the PPLO medium (Beef heart for infusions 50 g, peptones 10 g, NaCl 5 g and dextrose and horse serum additive) at one Incubation temperature of 3700 and an incubation time of 48 to 72 hours determined, The number of germs ingested was 107 germs / ml.

For yeasts and fungi, the MIC values were determined in 1% dextrose meat water - Broth, or in Sabourand broth (pH 6.5) at an incubation temperature of 28 0C and an incubation time of 72 to 96 hours determined, with the germination 105 and 103 germs per ml, respectively.

Table 1 Minimum inhibitory concentrations (MIC) (γ / ml nutrient medium) of 3- (5'-nitro-2'-furfurylidene) -N-methyl-oxindole Germ number of MIC γ / ml Tribes Proteus mirabilis 5 1.56-12.5 vulgaris 5 0.8 rettgeri 5 0.02-1.56 morgani 5 0.2-0.8 Escherichia coli 10 0.2-0.8 Salmonella (various 10 0.2-3.12 Species) Pseudomonas aeru- ginosa 11 0.4-12.5 Pasteurella mul- tocida 5 0.05-0.2 Klebsiella pneumatic moniae 4 0.1-0.8 Bordetella bron- chiseptica 1 12.5 Alcaliegenes faecalis 1 6.25 Sarcinen 2 0.1-0.2 Neisseria 4 0.1-1.56 Corynebacterium 0.02-0.4 pyogenes 3 Streptoc. faecalis 5 0.02-6.25 Continuation of table 1: Germ number of MIC γ / ml Tribes Streptococci 4 0.05-0.4 (different spec cies) Staphylococcus 18 0.05-0.4 aureus Mycoplasma 4 0.02-50 (different Species) Candida albicans 2 4-20 Table 2 Minimum inhibitory concentration (MIC) (γ / ml nutrient medium) of 3- (5'-nitro-2'-furfurylidene) -N-methyl-oxindole Type of germ Number of the number of sensitive strains Strains at .... γ / ml nutrient medium 0.02-0.2 0.4-0.8 1.56-625 12.5-> Proteus mirabilis 5 4 1 "vulgaris 5 5 "rettgeri 5 1 3 1 "morgani 5 2 3 Klebsiella 4 2 1 1 Sarcines 2 2 Streptococcus faecalis 5 4 1 Streptococci 4 2 2 Staphylococci 18 16 2 Corynebacteria 2 1 1 Table 3 Minimum inhibitory concentrations (in γ / ml nutrient medium) of some further compounds of the formula I: Number of germs R2 '= H R2' = 6-CH3 R2 '= 7-Cl R2' = H the Strains R1 '= i.-C4H9 R1' = C2H5 R1 '= C2H5 R1' = C2H5 Staphylococcus aureus 3 0.8 0.1-0.3 0.1-0.3 0.1-0.2 Sarcinen 2 1.6-50 3.2-6.2 3.1-12.5 0.8 Streptococcus (different Species) 3 1.6-50 0.6-50 3.1-12.5 0.02-25 Corynebacterium pyogenes 2 50 25-50 3, @ 0.4-12.5 Escherichia coli 2 200 50 50 1.6-12.5 Klebsiella pneumoniae 1 200 50 12.5 0.8 Neisserien (ver different species) 4 0.1-25 0.8-3.1 0.08-2.4 0.2-0.8 Mycoplasma (different Species) 8 0.25-25 <0.8- <0.8-50 <0.8-12.5 100 2. In vivo experiments a.) Three test persons were painted 3 (5t -nitro-21-furfurylidene) N-methyl-oxindole, incorporated into a paste that adheres to the mucous membrane and contained 2% active ingredient, into the oral cavity.

After a contact time of 30 minutes, the paste was removed and the oral cavity flora checked microbiologically on the blood plate. In two cases, germs could at all can no longer be detected, in one case the number of germs was greatly reduced.

b.) In cows suffering from mastitis, 3- (5'-nitro-2'-furfurylidene) -N-methyl-oxindole was used once in a dose of 500 mg per udder quarter as an intracisternal suspension applied. The bacteriological control after 24 hours showed that the germs were greatly reduced, in some cases completely eliminated1 Further controls after 36 and 48 hours showed the same result.

3. Effectiveness of the compounds of the formula I as feed additives In the feeding trial, day-old male chicks were given mixed feed and water ad libitum The control and test groups each consisted of 20 animals. The average weight gain of the chicks in% was determined.

Average weight gain in% Test groups after 14 days after 4 weeks Control group: 100.0 100.0 Feeding without Feed additives Test group: Feeding with forage that a.) 20 ppm 106.1 111.0 b.) 50 ppm 115.2 115.7 3- (5'-nitro-2'-furfurylidene) - N-methyl-oxindole contained.

Examples of the production of antimicrobial agents according to the invention (Formulation examples) 1. 0.1% ointment for local treatment, 0.1 g of active ingredient of formula I are rubbed with 5 g of viscous paraffin oil. Then will so much ointment base made of paraffin oil and polyethylene was added that a total of 100 g of ointment are created.

2.1% cream for local treatment 1 g active ingredient of formula 1, 20 g sorbitan monostearate, 15 g polyoxyethylene sorbitan monostearate, 30 g whale rat, 100 g sodium cetyl sulfate, 135 g 2-octyldodec, anol (99-100% fat content) and 10 g benzyl alcohol are mixed, mixed with enough water that 1 kg of mixture is produced and good stirred.

3. 10% suspension juice for oral application to a mixture of 10 g of active ingredient of the formula I, 0.05 g of sodium saccharin and 2 g of colloidal silica soyiel vegetable oil is given that a total of 100 ml of suspension juice is produced.

4. Tablets for oral application containing 20 mg of active ingredient 0.2 g of the active ingredient of the formula I with 1 g of lactose and 0.3 g of corn starch with 0.1 g granulated corn starch paste.

The mixture is passed through a sieve with a mesh size of approx. 4 to 6 mm and dried. This dried mixture is passed through a sieve with 0.8 to 1 mm Mesh size homogenized and then with 0.15 g starch and 0.02 g magnesium stearate mixed. The mixture thus obtained is compressed into 10 tablets.

The preparation of the compounds which can be used according to the invention is said to be illustrated by the following production examples: Example 1: 3- (5'-Nitro-2'-furfurylidene) -N-methyl-oxindole 14.1 g (0.1 mol of 5-nitrofurfural and 14.7 g (0.1 mol) of N-methyloxindole are in 50 ml of acetic anhydride heated under reflux for one hour. On cooling, the 3- (5'-nitro-2 ' furfurylidene) -N-methyl-oxindole in the form of red-violet crystals, which are suctioned off and recrystallized from methyl glycol.

Yield: 19 g (70 ffi of theory) melting point 215-2170 ° C. (after previous Sintering).

In a manner analogous to Example 1, the examples obtained are compounds Mp (00) 2 3- (5'-nitro-2'-furfurylidene) -N- 164 - 166 ethyl-oxindole 3 3- (5'-nitro-2'-furfurylidene) -N- 166-168 isobutyl-oxindole 4 3- (5'-nitro-2'-furfurylidene) -7-212-213 methyl-N-methyl-oxindole 5 3- (5'-nitro-2'-furfurylidene) -7- 173 chloro-N-ethyl-oxindol 6 3- (5'-nitro-2'-furfurylidene) -6- 19? methyl-N-ethyl-oxindole 7 3- (5'-nitro-2'-furfurylidene) -5- t 214-216 * methyl-N-ie thyl-oxindole 8 3- (5'-nitro-2'-furfurylidene) -5-175-178 * methyl-N-ethyl-oxindole *) after previous sintering The oxindoles required as starting compounds are partly known, or can be obtained by known processes.

Claims (6)

Patent claims: 1. Antimicrobial agent, characterized by a content of at least one nitrofuran derivative of the formula in which R1 stands for an alkyl radical and R2 stands for hydrogen, an alkyl group, an alkoxy group, a nitro group or halogen. 2. A method of making an antimicrobial agent, thereby characterized in that nitrofuran derivatives according to the formula in claim 1 with inert, mixed with non-toxic, pharmaceutically suitable carriers. 3. Animal feed, animal feed concentrates and preparations containing vitamins and / or mineral salts, characterized by a content of at least one nitrofuran derivative of the formula in which R1 stands for an alkyl radical and R2 stands for hydrogen, an alkyl group, an alkoxy group, a nitro group or halogen. 4. Use of nitrofuran derivatives according to the formula in claim 4 in animal husbandry. 5. Antimicrobial agent in dosage units, characterized in that that it contains a nitrofuran derivative according to the formula in claim 1 or of one such a nitrofuran derivative exists. 6. Antimicrobial agent In the form of tablets, pills, coated tablets and capsules, characterized in that it is a nitrofuran derivative according to the formula in claim 1 contains or consists of such a nitrofuran derivative.