HRP20010918A2 - Endoparasiticidal compositions - Google Patents

Abstract

The invention relates to the use of piperazines for potentiating the endoparasiticidal action of cyclic depsipeptides in endoparasiticidal agents. Said depsipeptides are comprised of amino acids and hydroxycarboxylic acids serving as ring structural elements and having 24 ring atoms. The invention also relates to agents of this type and to the use of piperazines and cyclic depsipeptides, said depsipeptides being comprised of amino acids and hydroxycarboxylic acids serving as ring structural elements and having 24 ring atoms, in order to produce endoparasiticidal agents.

Description

The present invention relates to the use of piperazine to increase the endoparasiticidal effect of cyclic depsipeptides in endoparasiticidal agents.

Piperazines and their activity against endoparasites are generally known. (Melhorn et al., Diagnostik und Therapie der Parasitosen des Menschen, second edition, Gustav Fischer Verlag, (1995), Melhorn et al., Diagnostik und Therapie der Parasitosen von Haus-, Nutz- und Heimtieren, second edition, Gustav Fischer Verlag , (1993).)

The cyclic depsipeptide PF 1022 and its activity against endoparasites is described in EP-OS 382 173.

Further cyclic depsipeptides and their endoparasitic activity are the subject of EP-OS 0 626 375, EP-OS 0 626 376 and WO 93/25543.

The subject of the present invention is the use of piperazine to increase the endoparasiticidal effect of cyclic depsipeptides consisting of amino acids and hydroxycarboxylic acids as ring building units and 24 ring atoms.

The subject of the present invention is furthermore endoparasitic preparations containing piperazines together with cyclic depsipeptides consisting of amino acids and hydroxycarboxylic acids as ring building units and 24 ring atoms.

The subject of the present invention is furthermore the application of piperazine together with cyclic depsipeptides consisting of amino acids and hydroxycarboxylic acids as ring building units and 24 ring atoms for the preparation of endoparasiticides.

Cyclic depsipeptides with 24 ring atoms include compounds of the general formula (I)

[image]

where

R1, R2, R11 and R12 independently represent C1-8-alkyl, C1-8-haloalkyl, C3-6-cycloalkyl, aralkyl, aryl,

R3, R5, R7, R9 independently of each other represent hydrogen or straight-chain or branched C1-8-alkyl, which can optionally be substituted with hydroxyl, C1-4-alkoxy, carboxy,

[image]

carboxamide,

[image]

imidazolyl, indolyl, guanidino, -SH or C1-4-alkylthio, and furthermore aryl or aralkyl which may be substituted with halogen, hydroxyl, C1-4-alkyl, C1-4- alkoxy,

R4, R6, R8, R10 independently of each other represent hydrogen, straight-chain C1-5-alkyl, C2-6-alkenyl, C3-7-cycloalkyl, each of which can optionally be substituted with hydroxyl, C1-4-alkoxy, carboxyl, carboxamide, imidazolyl, indolyl, guanidino, -SH or C1-4-alkylthio, as well as aryl or aralkyl which may be substituted with halogen, hydroxyl, C1-4-alkyl, C1-4-alkoxy,

and their optical isomers and racemates.

First of all, compounds of formula (I) are introduced, in which

R1, R2, R11 and R12 independently represent methyl, ethyl, propyl, isopropyl, n-, s-, t-butyl or phenyl, which are optionally substituted with halogen, C1-4-alkyl, OH, C1-4-alkoxy , as well as benzyl or phenylethyl, each of which may optionally be substituted by the residues indicated in the case of phenyl and

R3 to R10 have the above meaning.

Compounds of formula (I) are particularly advantageous, in which

R1, R2, R11 and R12 independently represent methyl, ethyl, propyl, isopropyl, n-, s-, t-butyl,

R3, R5, R7, R9 represent hydrogen, straight-chain or branched C1-8-alkyl, preferably methyl, ethyl, propyl, i-propyl, or n-, s-, t-butyl which can optionally be substituted with C1-4- Alkoxy, preferably methoxy, ethoxy, imidazolyl, indolyl or C1-4-alkylthio, preferably with methylthio, ethylthio, further represent phenyl, benzyl or phenethyl, which can optionally be substituted by halogen, preferably chlorine, and

R4, R6, R8, R10 mutually independently represent hydrogen, methyl, ethyl, n-propyl, n-butyl, vinyl, cyclohexyl, which can optionally be substituted with methoxy, ethoxy, imidazolyl, indolyl, methylthio, ethylthio, and represent isopropyl, s-butyl and further represent optionally halogen-substituted phenyl, benzyl or phenylethyl.

Furthermore, the compound PF 1022 of the following formula listed in EP-OS 382 173 can be considered a 24-membered ring depsipeptide:

[image]

Furthermore, the compounds described in PCT application WO 93/19053 are called depsipeptides.

In particular, compounds of the following formula from PCT application WO 93/19053 can be mentioned:

[image]

where

Z represents morpholinyl, nitro, amino, mono- or dimethylamino, and preferably morpholinyl.

Furthermore, compounds of the following formula may be mentioned:

[image]

where

R1a, R2a, R3a, R4a independently of each other represent hydrogen, C1-10-alkyl or aryl, preferably phenyl, which can optionally be substituted with hydroxyl, C1-10-alkoxy or halogen.

Compounds of formula (I) can be prepared by cyclization of the open-chain octadepsipeptide of formula (II)

[image]

where

R1 to R12 have the aforementioned meaning,

in the presence of some diluent and in the presence of some coupling reagent.

Suitable coupling reagents are all compounds which are suitable for amide bond formation (cf., e.g., Houben-Weyl, Methoden der organischen Chemie, Vol. 15/2; Bodanszkv et al., Peptide Synthesis, Second Edition (Wiley/Sons, New York 1976).

The following reagents and methods are particularly advantageous: active ester method with pentafluorophenol (Pfp), N-hydroxy-succinimide, 1-hydroxybenzotriazole, coupling with carbodiimides, such as dicyclohexylcarbodiimide or N'-(3-dimethylaminopropyl)-N-ethyl- carbodiimide (Ebc), and the method of mixed anhydrides or coupling with phosphonium reagents, such as benzotriazol-1-yl-oxy-tris(dimethyl-aminophosphonium-hexafluorophosphate (BOP), bis(2-oxo-3-oxazolidinyl)-phosphine chloride (BOP- Cl), or with phosphonic acid esters, such as cyanophosphonic acid diethyl ester (DEPC) and diphenylphosphoryl azide (DPPA).

The coupling with bis(2-oxo-3-oxazolidinyl-phosphonic acid chloride (BOP-Cl)) and N'-(3-dimethylamino-propyl)-N-ethylcarbodiimide (EDC) in the presence of 1-hydroxy-benzotriazole ( HOBt).

The conversion is carried out at temperatures from 0-150 °C, preferably at 20 to 100 °C, preferably at room temperature.

Suitable diluents are all inert organic solvents. They include primarily aliphatic and aromatic, optionally halogenated hydrocarbons, such as pentane, hexane, heptane, cyclohexane, petroleum ether, gasoline, ligroin, benzene, toluene, methylene chloride, ethylene chloride, chloroform, carbon tetrachloride, chlorobenzene and o-dichlorobenzene, further ethers such as diethyl and dibutyl ether, glycol, dimethyl ether and diglycol dimethyl ether, tetrahydrofuran and dioxane, further ketones such as acetone, methyl ethyl ketone, methyl isopropyl ketone and methyl isobutyl ketone, further esters such as methyl acetate and ethyl acetate, further nitriles, e.g. acetonitrile and propionitrile, benzonitrile, dinitrile glutaric acid, further amides, for example dimethylformamide, dimethylacetamide and N-methylpyrrolidone, and also dimethylsulfoxide, tetramethylenesulfone and hexamethylphosphoric acid triamide.

Compounds of formula (II) and coupling reagents are added in a mutual ratio of 1:1 to 1:5. An approximately equimolar ratio is preferred.

After the conversion, the diluent is removed by distillation and the compounds of formula (I) are purified in the usual way, for example by chromatography.

Open-chain octadepsipeptide of formula (II)

[image]

in which the radicals have the previously described meaning, are obtained by hydrogenolysis of compounds of formula (III)

[image]

where

A represents benzyl, a

R1 to R12 have the above meaning

in the presence of some diluent and some catalyst.

Compounds of formula (III)

[image]

in which the residues have the above meaning, are obtained by hydrolysis of compounds of formula (IV)

[image]

in which the radicals A and R1 to R12 have the above meaning, and B represents t-butoxy.

Compounds of formula (IV) and their stereoisomers are obtained by condensation of tetradepsipeptides of formula (V)

[image]

where

A represents benzyl i

Z represents OH, a

R1, R2, R3, R4, R5 and R10 have the above meaning,

and tetradepsipeptide of formula (VI)

[image]

where

D represents hydrogen and

B represents tert-butoxy, a

R6, R7, R8, R9, R11 and R12 have the above meaning,

in the presence of diluent and coupling reagent.

Tetradepsipeptides of formula (V) are obtained by saponification of tetradepsipeptides of formula (VII)

[image]

where

A represents benzyl i

B represents tert-butoxy, a

R1, R2, R3, R4, R5 and R10 have the above meaning,

in the presence of diluent and protonating acid.

Tetradepsipeptides of formula (VI)

[image]

where

D represents hydrogen and

B represents tert-butoxy, and the other residues have the above meaning,

were obtained by hydrogenolysis of tetradepsipeptide of formula (VII)

[image]

where

A represents benzyl i

B represents tert-butoxy, a

R1, R2, R3, R4, R5 and R10 have the above meaning,

in the presence of some diluent and some catalyst.

Tetradepsipeptides of formula (VII) are obtained by condensation of didepsipeptides of formula (VIII)

[image]

where

A represents benzyl i

Z represents OH, a

R1, R3 and R10 have the above meaning,

and didepsipeptide of formula (IX)

[image]

where

D represents hydrogen and

B represents tert-butoxy, a

R2, R4 and R5 have the above meaning,

in the presence of a coupling reagent.

The depsipeptides known from WO 93/19 053 or from EP-OS 382 173 can be obtained according to the methods described there.

Piperazines include all compounds of formula (X)

[image]

where

R13 and R14 mutually independently represent the same or different substituents from the group consisting of hydrogen, always in a given case substituted alkyl, cycloalkyl, aryl, heteroaryl, and -CONR15R16 or -CSNR15R16, in which R15 and R16 independently represent the same or different substituents from the group consisting of hydrogen, in a given case substituted alkyl or cycloalkyl.

Compounds of formula (X) in which

R13 and R14 mutually independently represent the same or different substituents from the group consisting of hydrogen, in a given case substituted C1-C6-alkyl, C3-C8-cycloalkyl, and -CONR15R16 or -CSNR15R16, in which R15 and R16 independently represent the same or different substituents from the group consisting of hydrogen, in a given case substituted C1-C6-alkyl or C3-C8-cycloalkyl.

Compounds of formula (X) in which

R13 and R14 mutually independently represent the same or different substituents from the group consisting of hydrogen, in a given case substituted C1-C4-alkyl, C6-cycloalkyl, and -CONR15R16 or -CSNR15R16, in which R15 and R16 independently represent the same or different substituents from groups consisting of hydrogen, in a given case substituted C1-C4-alkyl or C6-cycloalkyl.

Compounds of formula (X) in which

R13 and R14 independently represent the same or different substituents from the group consisting of hydrogen, C1-C4-alkyl, C1-C4-haloalkyl with 1 to 9 same or different halogen atoms from the series F, Cl or Br, C6-cycloalkyl, as well as -CONR15R16 or -CSNR15R16, in which

R15 and R16 independently represent the same or different substituents from the group consisting of hydrogen, C1-C4-alkyl or C6-cycloalkyl.

For example, but without limitation, the following compounds can be listed:

piperazine, diethylcarbamazine, N,N'-dimethylpiperazine, N-methylpiperazine, N,N'-diethylpiperazine, N-ethylpiperazine, N-ethyl-N'-methylpiperazine, N,N'-dipropylpiperazine, N-propylpiperazine, N-ethyl- N'-propylpiperazine, N-methyl-N'-propylpiperazine, N-cyclohexylpiperazine, N,N'-dicyclohexyl-piperazine,

[image]

whereby piperazine and diethylcarbamazine can be particularly prominent.

Piperazines are generally known organic compounds and are commercially available or can be prepared by known methods. (Melhorn et al. Diagnostik und Therapie der Parasitiosen des Menschen, second edition, Gustav Fischer (1995), Melhorn et al. Diagnostik und Therapie des Parasitosen von Haus-, Nutz- und Heimtieren, second edition, Gustav Fischer (1993)).

Preparations according to the invention are suitable for the control of pathogenic endoparasites that occur in humans and in the case of keeping and breeding animals, agricultural animals, farmed animals, zoo animals, laboratory animals, experimental animals and pets, and have favorable toxicity in warm-blooded animals.

They are effective against all or individual developmental stages of the pest and also against resistant and normally susceptible species. Suppression of pathogenic endoparasites should reduce disease, mortality and yield reduction (eg in the production of meat, milk, wool, leather, eggs, honey, etc.), so that the use of active substances makes it possible to maintain animals more economically and simply. Pathogenic endoparasites include cestodes, trematodes, nematodes, acanthocephals, primarily:

From the order Pseudophyllidea, for example: Diphillobothrium spp., Spirometra spp., Schistocephalus spp., Ligula spp., Bothridium spp., Diphlogonoporus spp..

From the Cyclophyllidea order, e.g.: Mesocestoide spp., Anoplocephala spp., Paranoplocephala spp., Moniezia spp., Thysanosomosa spp., Thysaniezia spp., Avitellina spp., Stilesia spp., Cittotaenia spp., Andrya spp., Bertiella spp. , Taenia spp., Echinococcus spp., Hydatigera spp., Davainea spp., Raillietina spp., Hymenolepis spp., Echinolepis spp., Echinocotyle spp., Diorchis spp., Dipylidium spp., Joyeuxiella spp., Diplopylidium spp.

From the subspecies Monogenea, eg: Gyrodactylus spp., Dactylogyrus spp., Polystoma spp..

From the subspecies Digenea, e.g.: Diplostomum spp., Posthodiplostomum spp., Schistoma spp., Trichobilharzia spp., Ornithobilharzia spp., Austrobilharzia spp., Gogantobilharzia spp., Leucochloridum spp., Brachylaima spp., Echinostoma spp., Echinoparphium spp. . spp., Notocotylus spp., Catatropis spp., Plagiorchis spp., Prostoghonimus spp., Dicrocelium spp., Eurytrema spp., Troglotrema spp., Paragonimus spp., Collyriclum spp., Nanophyetus spp., Opishorchis spp., Clonorchis spp. , Metorchis spp., Heterophyes spp., Metagonimus spp..

From the Enoplida species, e.g.: Trichuris spp., Capillaria spp., Trichomosoides spp., Trichinella spp..

From the species Rhabditia, eg: Micronema spp., Strongyloides spp..

From the species Strongylida, e.g.: Stronylus spp., Triodontophorus spp., Oesophagodontus spp., Trichonema spp., Gyalocephalus spp., Cylindropharynx spp., Poteriostomum spp., Cyclococercus spp., Cylicostephanus spp., Oesophagostomum spp., Chabertia spp. , Stephanurus spp., Ancylostoma spp., Uncinaria spp., Bunostomum spp.,

Globocephalus spp., Syngamus spp., Cyathostomum spp., Metastrongylus spp., Dictyocaulus spp., Nuellerius spp., Protostringylus spp., Neostrongylus spp., Cystocaulus spp., Pneumostrongylus spp., Spicocaulus spp., Elaphostrongylus spp., Parelaphostrongylus spp. ., Crenosoma spp., Paracrenosoma spp., Angiostrongylus spp., Aelurostrongylus spp., Filaroides spp., Parafilaroides spp., Trichostrongylus spp., Haemonochus spp., Ostertagis spp., Marshallagia spp., Cooperia spp., Nematodirus spp., Hyostrogylus spp., Obeliscoides spp., Amidostomum spp., Ollulanus spp., Cylicocyclus spp., Crateostonum spp., Cylicodontophorus spp..

From the order Oxyurida, for example: Oxyuris spp., Enterobius spp., Passsalarus spp., Syphacia spp., Ascpiculuris spp., Heterakis spp..

From the order Ascaridia, for example: Ascaris spp., Toxascaris spp., Toxocara spp., Parascaris spp., Anisakis spp., Ascaridia spp..

From the Spirurida order, e.g.: Gnathostoma spp., Physaloptera spp., Thelazia spp., Gongylonema spp., Habronema spp., Parabronema spp., Draschia spp., Dracunculus spp..

From the order Filariida, e.g.: Stephanofilaria spp., Parafilaria spp., Setaria spp., Los spp., Dirofilaria spp., Litomosoide spp., Brugia spp., Wuchereria spp., Onchocerca spp..

From the order Gogantorhynchida, for example: Filicollis spp., Moniliformis spp., Macaracanthorhynchus spp., Prostenorchis spp..

Agricultural and breeding animals include mammals such as cattle, horses, sheep, pigs, goats, camels, water buffalo, donkeys, rabbits, fallow deer, roe deer, furbearers such as minks, chinchillas, raccoons, birds such as chickens, geese, turkeys, ducks, ostriches, freshwater and marine fish such as trout, carp, eels, reptiles, insects such as bees and silkworms.

Laboratory and experimental animals include mice, rats, guinea pigs, golden hamsters, dogs and cats.

Pets include dogs and cats.

It can be used prophylactically as well as therapeutically.

The application of the mixture of active substances takes place directly or in the form of suitable preparations enterally, parenterally, dermally, nasally, by environmental treatment or with the help of modeled articles containing the active compound, such as strips, plates, ribbons, collars, ear pendants, limb tourniquets , markers.

Enteral administration of mixtures of active compounds is carried out orally, for example, in the form of powders, tablets, capsules, pastes, drinks, granules, solutions for oral administration, suspensions and emulsions, "boli", medical food or drinking water. Dermal application is carried out for example in the form of soaking, spraying or pouring and dripping. Parenteral administration is carried out, for example, in the form of injections (intramuscular, subcutaneous, intravenous, intraperitoneal) or by implantation.

Suitable preparations are:

- solutions as injection solutions, oral solutions, concentrates for oral administration after dilution, solutions for skin application or for body openings, soaking preparations, gels;

- emulsions and suspensions for oral and dermal use and for injections; semi-solid preparations;

- formulations in which the mixture of the active compound is incorporated into a fat-based base or an oil-in-water or water-in-oil emulsion;

- solid preparations such as powders, premixes or concentrates, granules, lozenges, tablets, "bolis", capsules; aerosols and inhalants, modeled articles with a mixture of the active compound.

Injection solutions are administered intravenously, intramuscularly or subcutaneously.

Injection solutions are prepared by dissolving the active compound mixture in a suitable solvent with the possible addition of appropriate additives such as auxiliary solvents, acids, bases, buffer salts, antioxidants, preservatives. The solutions are sterile filtered and stored in bottles.

Solvents include: physiologically acceptable solvents such as water, alcohols such as ethanol, butanol, benzyl alcohol, glycerol, propylene glycol, polyethylene glycol, N-methylpyrrolidone, as well as their mixtures.

The active compound mixture may optionally be dissolved in physiologically acceptable vegetable or synthetic oils suitable for injection.

Auxiliary solvents can be: solvents that promote dissolution of the active compound mixture in the main solvent or prevent precipitation. Examples are polyvinylpyrrolidone, polyoxyethylated castor oil, polyoxyethylated sorbitan ester.

Preservatives are: benzyl alcohol, trichlorobutanol, p-hydroxy-benzoic acid ester, n-butanol.

Oral solutions are applied directly. Concentrates are administered orally after previous dissolution to the prescribed concentration. Oral solutions and concentrates previously described, in the case of injectable solutions, must be suitable for administration under sterile conditions.

Solutions for skin application are applied by dripping, coating, rubbing, spraying or spraying. These solutions are prepared as previously described for injection solutions.

It may be convenient to add thickeners during preparation. Thickeners are: inorganic Thickeners such as bentonites, silicic acid colloids, aluminum monostearate, organic Thickeners such as cellulose derivatives, polyvinyl alcohols and their copolymers, acrylates and methacrylates.

Gels are applied or coated on the skin or introduced into body cavities. Gels are prepared by reconstituting the solutions, which are prepared as described for the injection solutions, with enough thickener to obtain a clear mass of the consistency of fat. As Thickeners, the above-mentioned Thickeners are added.

Top-on formulations are applied by pouring or spraying onto limited areas of the skin, whereby the active compound penetrates the skin and acts systemically.

Pour-on formulations are prepared by dissolving, suspending or emulsifying a mixture of the active compound in suitable, skin-tolerable solvents or solvent mixtures. Optionally, the following auxiliary substances are added, such as dyes, agents for increasing resorption, antioxidants, light protection agents, adhesives.

Solvents can be: water, alkanols, glycols, polyethylene glycols, polypropylene glycols, glycerol, aromatic alcohols such as benzyl alcohol, phenylethanol, phenoxyethanol, esters such as ethyl acetate, butyl acetate, benzyl benzoate, ethers such as alkylene glycol, alkyl ethers such as dipropylene glycol monomethyl ether, diethylene glycol monobutyl ether , ketones such as acetone, methyl ethyl ketone, aromatic and/or aliphatic hydrocarbons, vegetable and synthetic oils, DMF, dimethylacetamide, N-methylpyrrolidone, 2,2-dimethyl-4-oxy-methylene-1,3-dioxolane.

Dyes are all colored reagents that can be dissolved or suspended, and are allowed for use in animals.

Agents for increasing resorption are, for example, DMSO, lubricants such as isopropyl myristate, dipropylene glycol pelargonate, silicone oils, fatty acid esters, triglycerides, fatty alcohols.

Antioxidants are sulfites or metabisulfites such as potassium metabisulfite, ascorbic acid, butylhydroxytoluene, butylhydroxyanisole, tocopherol.

A means of protection against light is, for example, novantisolic acid.

Adhesives are, for example, cellulose derivatives, starch derivatives, polyacrylates, natural polymers such as alginates, gelatin.

Emulsions can be administered orally, dermally or as injections.

Emulsions are either water-in-oil or oil-in-water.

They are prepared by dissolving a mixture of the active compound in hydrophobic or hydrophilic phases, and are homogenized with the solvent of the second phase, with the addition of a suitable emulsifier and optional auxiliaries such as dyes, agents for increasing resorption, antioxidants, agents for protecting against light, substances for increasing viscosity.

The hydrophobic phase (oils) can include: paraffin oils, silicone oils, natural vegetable oils such as sesame, almond, castor oil, synthetic triglycerides such as caprylic/caproic biglyceride, mixtures of triglycerides with vegetable fatty acids of chain length C8-12 or other specially selected natural fatty acids, partial glyceride mixtures of saturated or unsaturated fatty acids that may possibly have a hydroxyl group, mono- and diglycerides of C8/C10 fatty acids.

Fatty acid esters such as ethyl stearate, di-n-butyriatate, hexyl laurate, dipropylene glycol pelargonate, esters of medium-chain branched fatty acids with saturated fatty alcohols of chain length C16-C18, isopropyl myristate, isopropyl palmitate, esters of caprylic/caproic acid with saturated fatty alcohols of chain length C12-C18, isopropylstearate, oleyl oleate, decyl oleate, ethyl oleate, ethyl lactate, wax fatty acid esters such as duck fat, dibutyl phthalate, diisopropyl adipate, related ester mixtures, and others.

Fatty alcohols such as isotridecyl alcohol, 2-octyldodecanol, cetylstearyl alcohol, oleyl alcohol.

Fatty acids such as oleic acid and its mixtures.

The following can be mentioned as hydrophilic phases: Water, alcohols such as propylene glycol, glycerol, sorbitol and their mixtures.

Emulsifiers can be:

- nonionic surfactants, eg polyoxyethylated castor oil, polyoxyethylated sorbitan monooleate, sorbitan monostearate, glycerol monostearate, polyoxyethylstearate, alkylphenol polyglycolether;

- ampholytic surfactants such as di-Na-N-lauryl-p-iminodipropionate or lecithin;

- anionic surfactants such as Na-laurylsulfate, fatty alcohol ether sulfates, mono/dialkylpolyglycol ether-orthophosphoric acid ester-monoethanolamine salt;

- cationic surfactants such as cetyltrimethylammonium chloride.

Additional auxiliary substances should include: substances that increase the viscosity and stabilize the emulsion such as carboxymethylcellulose, methylcellulose and other celluloses and starch derivatives, polyacrylates, alginates, gelatin, gum arabic, polyvinylpyrrolidone, polyvinyl alcohol, copolymers of methyl vinyl ether and maleic anhydride, polyethylene glycols, waxes , colloidal silicic acid or mixtures of the aforementioned substances.

Suspensions can be administered orally, dermally or as injections. They are prepared by suspending the active substance in a carrier liquid, optionally with the addition of further auxiliary substances such as crosslinkers, dyes, agents to increase resorption, preservatives, antioxidants, and light protection agents.

Carrier liquids can be all homogeneous solvents and solvent mixtures.

Crosslinkers (dispersing agent) can be the surfactants mentioned above.

Further excipients may be those listed above.

Semi-solid preparations can be administered orally or dermally. They differ from the suspensions and emulsions described above only by their higher viscosity.

For the preparation of solid preparations, the active compound is mixed with suitable carriers, optionally with the addition of excipients, and converted into the desired form.

Carriers can be any physiologically acceptable solid inert substances. Inorganic and organic substances can be used. Inorganic substances are, for example, sodium chloride, carbonates such as calcium carbonate, hydrogen carbonates, aluminum oxide, silicic acids, diatomaceous earth, precipitated or colloidal silicon dioxide, phosphates.

Organic substances are, for example, sugar, cellulose, food substances and beverages such as milk powder, animal flour, cereal flour and raw cereal meals, starches.

Auxiliary substances are preservatives, antioxidants and dyes, which were previously mentioned.

Suitable additional auxiliaries are lubricants and glidants such as magnesium stearate, stearic acid, talc, bentonites, disintegrants such as starches or cross-linked polyvinylpyrrolidone, binders such as starches, gelatin or linear polyvinylpyrrolidone, and dry binders such as microcrystalline cellulose.

Mixtures of the active compound in the preparations may also be present as mixtures with other synergists or with other active compounds acting against pathogenic endoparasites. Such active compounds are, for example, L-2,3,5,6-tetrahydro-6-phenyl-imidazothiazole, benzimidazole carbamates, pyrantel.

Ready-to-use preparations contain mixtures of the active compound in concentrations of 10 ppm - 20% by mass, preferably from 0.1 - 10% by mass.

Preparations that are diluted before use contain mixtures of the active compound in concentrations of 0.5 - 90 wt.%, preferably from 5 to 50 wt.%.

In general, the advantage of prescribing the mixture according to the invention from approximately 10 to approximately 100 mg of the mixture of the active compound per kg of body weight per day, to achieve efficient results, has been proven. 10 to 50 mg of the active compound mixture per kg of body weight is preferred.

In the means, the mass ratio of piperazine to depsipeptide is generally maintained from 50:1 to 1000:1, preferably 100:1 to 1000:1, especially 250:1 to 1000:1, preferably 250:1 and 1000:1.

In biological examples, it is a compound of the formula

[image]

described in WO 93/19053, introduced as "depsipeptide I".

Biological tests were carried out according to known procedures (Plant et al. Pesticide Science, 1996, 48, p. 351 ff.).

Biological examples

Table 1

Synergistic effect of piperazine and depsipeptide I against Trichinella spiralis in vitro

[image] 0= no effect; 1 = weak performance; 2 = good performance

Table 2

Synergistic effect of piperazine and depsipeptide I against mouse nematodes

[image] 0 = reduction of intruders < 50%; 1 = reduction of intruders 50-75%; 2 = reduction of intruders 75-90%; 3 = full effect, pest reduction >90%

Examples of preparation

Examples of preparation of cyclic depsipeptides with 24 ring atoms:

1. Preparation of compounds of formula (I).

BOP-Cl (0.124 mmol) was added at 0°C to a solution of the compound of formula II (0.104 mmol) and Hunig's base (0.258 mmol) in dichloromethane (100 ml) and the mixture was stirred at room temperature for 24 hours. After this time, the same amounts of BOP-Cl and base were added and stirred for a further 24 hours. The solution was washed twice with saturated sodium bicarbonate solution, dried over sodium sulfate and concentrated. The residue was purified through a chromatographic column with cyclohexane/ethyl acetate 2:1 as solvent.

Compounds of formula (I) were obtained, in which the substituents have the following meanings (Table 3):

Table 3[image]

Examples of preparation of compounds of formula (II)

A solution of the open-chain octadepsipeptide of formula (III) (1,222 mmol) in ethanol (50 ml) was hydrated in the presence of Pd(OH)2/C (20 %; 200 mg) until complete hydrogen uptake (about 2 h). After filtering the catalyst, a pure compound of formula (II) was obtained, which was further converted without additional purification.

According to this regulation, compounds of formula (II) were obtained, in which the substituents have the meaning according to Table 4.

Table 4

[image]

Me = methyl

Et = ethyl s-Bu = s-butyl Bn = benzyl

Preparation of compounds of formula (III)

Gaseous HCl was bubbled through a solution of tert-butyl ester of formula (IV) (1.609 mmol) in dichloromethane (40 ml) at 0 °C for 1.5 h. The mixture was then heated to room temperature and stirred for 12 h. The solution was concentrated using a rotavapor and dried under high vacuum. The remainder was converted without further purification.

Compounds of formula (III) were obtained analogously, in which the substituents have the following meaning (Table 5):

Table 5[image]

Preparation of compounds of formula (IV)

A solution of ethyldiisopropylamine (0.912 mmol) and BOP-Cl (0.438 mmol) was added at 0°C to a solution of tetradepsipeptides of formula (VI) and (V) (2.52 mmol each) in dichloromethane (15 ml). The mixture was stirred at 0°C for 1 h, and at room temperature for 1.5 h, diluted with 20 ml of dichloromethane, washed twice with a little water, dried over Na2SO4 and concentrated. The residue was purified on silica gel with cyclohexane/t-BuOMe = 2:1 as eluent.

Preparation of compounds of formula (V)

Gaseous HCl was introduced at 0°C for 2 h into a solution of tetradepsipeptide of formula (VII) (2,848 mmol) in dichloromethane (50 ml). The mixture was then stirred at room temperature for 8 h, concentrated and dried under high vacuum. The residue was used further without additional purification.

Preparation of compounds of formula (VI)

A solution of tetradepsipeptide of formula (VII) (9.53 mmol) in ethanol (37 ml) was treated with Pd(OH)2/C (20 %) (0.6 g) and hydrated at room temperature and normal pressure for about 3 hours. The reaction mixture was filtered, concentrated and the residue was separated on silica gel with the eluent t-BuOMe/cyclohexane/ethanol = 1:1:0.5.

Preparation of compounds of formula (VII)

A solution of depsipeptide IX (22.9 mmol) and depsipeptide VIIIa (27.5 mmol) in dichloromethane (80 ml) cooled to 0 °C was treated with diisopropylethylamine (57.3 mmol) and BOP-Cl (29.8 mmol), stirred at 0 °C for 1 h and at room temperature for 1 h. After filtering the precipitate, the solution was diluted with dichloromethane, washed three times with a little water, dried over sodium sulfate and concentrated. The residue was separated on silica gel with the eluent cyclohexane/ethyl acetate = 15:1.

Claims (10)

1. Application of piperazine to increase the endoparasiticidal effect of cyclic depsipeptides, characterized by the fact that they consist of amino acids and hydroxycarboxylic acids as ring building units and with 24 ring atoms. 2. Endoparasiticides, characterized by the fact that they contain piperazines together with cyclic depsipeptides consisting of amino acids and hydroxycarboxylic acids as ring building units and of 24 ring atoms. 3. Application of piperazine, characterized by the fact that it is together with cyclic depsipeptides consisting of amino acids and hydroxycarboxylic acids as ring units and of 24 ring atoms for the preparation of endoparasiticidal agents. 4. Application of piperazine according to claim 1, indicated by the fact that cyclic depsipeptides correspond to formula (I) [image] where R1, R2, R11 and R12 independently represent C1-8-alkyl, C1-8-haloalkyl, C3-6-cycloalkyl, aralkyl, aryl, R3, R5, R7, R9 independently of each other represent hydrogen or straight-chain or branched C1-8-alkyl, which can optionally be substituted with hydroxyl, C1-4-alkoxy, carboxy, [image] carboxamide, [image] imidazolyl, indolyl, guanidino, -SH or C1-4-alkylthio, and furthermore aryl or aralkyl which may be substituted with halogen, hydroxyl, C1-4-alkyl, C1-4- alkoxy, R4, R6, R8, R10 independently of each other represent hydrogen, straight-chain C1-5-alkyl, C2-6-alkenyl, C3-7-cycloalkyl, which can optionally be substituted with hydroxyl, C1-4-alkoxy, carboxyl, carboxamide, imidazolyl . as well as their optical isomers and racemates. 5. Use according to claim 4, characterized in that cyclic depsipeptides correspond to formula (I), in which R1, R2, R11 and R12 independently represent methyl, ethyl, propyl, isopropyl, n-, s-, t-butyl or phenyl, which are optionally substituted with halogen, C1-4-alkyl, OH, C1-4-alkoxy , as well as benzyl or phenylethyl, each of which may optionally be substituted by the residues indicated in the case of phenyl and R3 to R10 have the above meaning. 6. Application according to claim 4, characterized in that cyclic depsipeptides correspond to formula (I), in which R1, R2, R11 and R12 independently represent methyl, ethyl, propyl, isopropyl, n-, s-, t-butyl, R3, R5, R7, R9 represent hydrogen, straight-chain or branched C1-8-alkyl, preferably methyl, ethyl, propyl, i-propyl, or n-, s-, t-butyl which can optionally be substituted with C1-4- Alkoxy, preferably methoxy, ethoxy, imidazolyl, indolyl or C1-4-alkylthio, preferably with methylthio, ethylthio, further represent phenyl, benzyl or phenethyl, which can optionally be substituted by halogen, preferably chlorine, and R4, R6, R8, R10 mutually independently represent hydrogen, methyl, ethyl, n-propyl, n-butyl, vinyl, cyclohexyl, which can optionally be substituted with methoxy, ethoxy, imidazolyl, indolyl, methylthio, ethylthio, and represent isopropyl, s-butyl and further represent optionally halogen-substituted phenyl, benzyl or phenylethyl. 7. Use according to claims 1 or 4 to 6, characterized in that piperazines correspond to formula (X), [image] where R13 and R14 mutually independently represent the same or different substituents from the group consisting of hydrogen, always in a given case substituted alkyl, cycloalkyl, aryl, heteroaryl, and -CONR15R16 or -CSNR15R16, in which R15 and R16 independently represent the same or different substituents from the group consisting of hydrogen, in a given case substituted alkyl or cycloalkyl. 8. Use according to claims 1 or 4 to 6, characterized in that the piperazines correspond to the formula (X), in which R13 and R14 mutually independently represent the same or different substituents from the group consisting of hydrogen, in a given case substituted C1-C6-alkyl, C3-C8-cycloalkyl, and -CONR15R16 or -CSNR15R16, in which R15 and R16 independently of each other represent the same or different substituents from the group formed by hydrogen, in a given case substituted C1-C6-alkyl or C3-C8-cycloalkyl. 9. Use according to claims 1 or 4 to 6, characterized in that the piperazines correspond to the formula (X), in which R13 and R14 mutually independently represent the same or different substituents from the group consisting of hydrogen, in a given case substituted C1-C4-alkyl, C6-cycloalkyl, and -CONR15R16 or -CSNR15R16, in which R15 and R16 independently of each other represent the same or different substituents from the group consisting of hydrogen, in a given case substituted C1-C4-alkyl or C6-cycloalkyl. 10. Agent according to claim 2, characterized in that the cyclic depsipeptides correspond to one of the definitions given in claims 4 to 6 and/or that the piperazines correspond to the definitions given in claims 7 to 9.