Cyclic peptide antifungal agents and process for preparation thereof

Abstract: Provided are compounds of the formula (1): wherein R' is hydrogen, methyl or NH₂C(O)CH₂-; R'' is methyl or hydrogen; R is hydroxy or hydrogen; R₁ is hydroxy, hydrogen, or hydroxysulfonyloxy; R₇ is hydroxy, hydrogen, hydroxysulfonyloxy or phosphonooxy; R₂ is a novel acyl side chain. Also provided are novel formulations, methods of inhibiting fungal and parasitic activity, and a process for preparing dideoxy (R=H) forms of the compounds.

Description: Background of the Invention This invention relates to cyclic peptide antifungal agents. In particular, it relates to acyl derivatives of the echinocandin class of cyclic peptide antifungal agents; to methods for treating antifungal and parasitic infections, and to formulations useful in the methods. The compounds provided by this invention are semi-synthetic antifungal agents in that they are derived from the cyclic peptide antifungals which are produced by culturing various microorganisms. A number of cyclic peptide antifungals are known. Among these are echinocandin B (A30912A), aculeacin, mulundocandin, sporiofungin, L-671,329, FR901379, and S31794/F1. All such antifungals are structurally characterized by a cyclic hexapeptide core, or nucleus, the amino group of one of the cyclic amino acids bearing a fatty acid acyl group forming a side chain off the core or nucleus. For example, echinocandin B has a linoleoyl side chain while aculeacin has a palmitoyl side chain. These fatty acid side chains of the cyclic hexa- peptides can be removed by enzymatic deacylation to provide the free nucleus. (Formula (1), hereinafter, wherein R 2 is hydrogen.) Reacylation of the amino group of the nucleus provides semisynthetic antifungal compounds. For example, the echinocandin B nucleus provides a number of antifungal agents when reacylated with certain unnatural side chain moieties (see Debono , U.S. Pat. No. 4,293,489). Among such antifungal compounds is cilofungin which is represented by the formula (1) wherein R is methyl, R 1 is hydrogen and R 2 is p-(n-octyloxy)benzoyl. Enzymatic deacylation of the cyclic hexapeptides is carried out with deacylase produced by the organism Actinoplanes utahensis and related microorganisms as described by Abbott et al ., U.S. Pat. No. 4,293,482. The present invention provides acylated cyclic hexapeptides having unique side chain acyl groups which, inter alia impart enhanced antifungal and antiparasitic potency e.g. against pathogenic strains of Candida albicans . Also provided is a process for removing the aminal and benzylic hydroxy groups to result in a dideoxy compound of formula (1) (R = H). Summary of the Invention The compounds provided by this invention are represented by the following formula (1): wherein R' is hydrogen, methyl or NH 2 C(O)CH 2 -; R" and R"' are independently methyl or hydrogen; R and R y are independently hydroxy or hydrogen; R 1 is hydroxy, hydrogen or hydroxysulfonyloxy; R 7 is hydroxy, hydrogen, hydroxysulfonyloxy or phosphonooxy; and I) R 2 is a substituted benzoyl group represented by the formula wherein R 3 is quinolyl; or II) R 2 is an acyl group represented by the formula wherein Z is -C≡C-, -CH=CH-, or a carbon to carbon bond; A) R 4 is C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, C 3 -C 12 cycloalkoxy, naphthyl, pyridyl, thienyl, benzothienyl, quinolyl or phenyl; or B) R 4 is phenyl substituted by amino, C 1 -C 12 alkylthio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 substituted alkyl, C 2 -C 12 substituted alkenyl, C 2 -C 12 substituted alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, phenyl, substituted phenyl, phenyl substituted with a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m and n are integers of from 2 to 4, and p is 0 or 1; or C) R 4 is phenyl substituted with C 1 -C 6 alkoxy substituted by fluoro, bromo, chloro or iodo; or D) R 4 is a group represented by the formula -Y-R 6 wherein Y is -C≡C- or -C=C-; and R 6 is C 1 -C 12 alkyl, C 1 -C 12 substituted alkyl; C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, phenyl, C 3 -C 12 cycloalkenyl, naphthyl, benzothiazolyl, thienyl, phenyl substituted by amino, C 1 -C 12 alkylthio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, -O-(CH 2 ) p' -W-R 5 wherein p' is an integer of from 2 to 4; W is pyrrolidino, piperidino or piperazino, and R 5 is hydrogen, C 1 -C 12 alkyl, C 3 -C 12 cycloalkyl, benzyl or C 3 -C 12 cycloalkylmethyl; or C 1 -C 6 alkoxy substituted by fluoro, bromo, iodo or chloro; or R 6 is a phenyl substituted by a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m, n and p are as defined above; or R 2 is an acyl group represented by the formula wherein Z is -C≡C- or -CH=CH-; A) R 4 is hydrogen, C 2 -C 12 alkynyl, C 2 -C 12 substituted alkynyl, C 1 -C 12 alkoxy; or B) R 4 is C 1 -C 12 alkoxy substituted with C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, C 2 -C 12 alkynyl, amino, C 1 -C 4 alkylamino, di-(C 1 -C 4 alkyl)amino, C 1 -C 12 alkanoylamino, phenyl substituted with a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m,n and p are as defined; or C) R 4 is C 1 -C 12 alkoxy substituted with a group of the formula wherein R 8 is C 1 -C 6 alkoxy optionally substituted with phenyl; or D) R 4 is a group represented by the formula -O-(CH 2 ) p' -W-R 5 wherein p', W and R 5 are as defined; or IV) R 2 is a group having the formula wherein Y and R 6 are as defined above; or V) R 2 is naphthoyl substituted with R 4 wherein A) R 4 is C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, C 3 -C 12 cycloalkoxy, naphthyl, pyridyl, thienyl, benzothienyl, quinolyl or phenyl; or B) R 4 is phenyl substituted by amino, C 1 -C 12 alkylthio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 substituted alkyl, C 2 -C 12 substituted alkenyl, C 2 -C 12 substituted alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, phenyl, substituted phenyl, phenyl substituted with a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m, n and p are as defined; or C) R 4 is phenyl substituted with C 1 -C 6 alkoxy substituted by fluoro, bromo, chloro or iodo; or D) R 4 is a group represented by the formula -Y-R 6 wherein Y has the same meanings as defined above; and R 6 is C 1 -C 12 alkyl, C 1 -C 12 substituted alkyl; C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, phenyl, C 3 -C 12 cycloalkenyl, naphthyl, benzothiazolyl, thienyl, phenyl substituted by amino, C 1 -C 12 alkythio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, -O-(CH 2 ) p' -W-R 5 , or C 1 -C 6 alkoxy substituted by fluoro, bromo, iodo or chloro; or R 6 is a phenyl substituted by a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m, n and p are as defined above; and the pharmaceutically acceptable non-toxic salts thereof. Also provided are formulations and methods for inhibiting parasitic and fungal activity which employ the compounds of the invention, and a process for preparing the dideoxy form of the compounds. Detailed Description The term: "C 1 -C 12 alkyl" refers to the straight or branched chain alkyl hydrocarbon groups such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl groups; and the like. The term "C 2 -C 12 alkenyl" refers to groups such as vinyl, 1-propene-2-yl, 1-butene-4-yl, 1-pentene-5-yl, 1-butene-1-yl, and the like. The term "C 2 -C 12 alkynyl" refers to such groups as ethynyl, propynyl, pentynyl, butynyl and the like. The term "C 1 -C 12 alkylthio" refers to such groups as methylthio, ethylthio, t-butylthio, and the like. The term "C 1 -C 12 alkoxy" refers to the straight or branched chain oxyalkyl groups such as, e.g. methoxy, ethoxy, propoxy, butoxy, heptoxy, octyloxy, dodecyloxy, and the like. The term C 3 -C 12 cycloalkoxy" refers to such groups as cyclopropoxy, cyclobutoxy and the like. The term "C 3 -C 12 cycloalkenyl" refers to such groups as cyclopropenyl, cyclobutenyl, cyclopentenyl, and the like. The term "C 1 -C 12 substituted alkyl," "C 2 -C 12 substituted alkenyl", and "C 2 -C 12 substituted alkynyl", denotes the above substituted one or two times with halogen, hydroxy, protected hydroxy, amino, protected amino, C 1 -C 7 acyloxy, nitro, carboxy, protected carboxy, carbamoyl, carbamoyloxy, cyano, methylsulfonylamino, phenyl, substituted phenyl, or C 1 -C 12 alkoxy. The term "substituted phenyl" is represented by a phenyl group substituted with one, two, or three moieties chosen from halogen, hydroxy, protected hydroxy, cyano, nitro, C 1 -C 12 alkyl, C 1 -C 12 alkoxy, carboxy, protected carboxy, carboxymethyl, hydroxymethoyl, amino, aminomethyl trifluoromethyl or N-(methylsulfonylamino) The term "C 3 -C 12 cycloalkyl" refers to such groups as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl. The term "C 1 -C 4 alkylamino" refers to such groups as methylamino, ethylamino, n-butylamino and the like. The term "di-(C 1 -C 4 alkyl)amino" refers to such groups as dimethylamino, diethylamino, di-n-propylamino, di-n-butylamino, methylethylamino, methyl-n-butylamino, and like tertiary amino groups. The term "C 1 -C 12 alkanoylamino" refers to such groups as acylamino groups derived from the C 1 -C 12 carboxylic acids and are exemplified by formamido, acetylamino, propionylamino, butyrylamino, and the like, The term "C 3 -C 12 cycloalkylmethyl" refers to those C 3 -C 7 cycloalkyls described above further substituted by methyl. The terms "C 7 -C 10 bicycloalkyl" and "C 7 -C 14 tricycloalkyl" refer to such groups as bicyclo[2.2.1.]hept-2-yl, bicyclo[2.2.1.]hep-4-en-2-yl, bicyclo[3.3.1.]nona-3-yl, bicyclo[3.3.1.]nona-2-yl, bicyclo[3.2.1.]oct-2-yl, bicyclo[2.2.2.]oct-2-yl, bicyclo[2.2.2]oct-5-en-2-yl, adamantyl and the like. The term "dideoxy" refers to compounds of the formula (1) wherein R=H. The term "inhibiting", such as used in relation to the methods for inhibiting parasitic and fungal activity, is defined to mean its normal definition, i.e., to stop, retard or prophylactically hinder or prevent. The term "activity", as used in relation to parasitic and fungal activity, includes growth thereof and attending characteristics and results from the existence of the parasite or fungus. The term "contacting", as used in relation to the methods for inhibiting parasitic and fungal activity by contacting a compound of the invention with a parasite or fungus, is defined to mean its normal definition. However, the term does not imply any further limitations to the process, such as by mechanism of inhibition, and the methods are defined to encompass the spirit of the invention, which is to inhibit parasitic and fungal activity by the action of the compounds and their inherent anti-parasitic and anti-fungal properties, or in other words, the compounds, used in the method are the causative agent for such inhibition. Examples of acyl groups wherein R 2 is a group represented by the formula are diphenyl acetylenes (Z=-C≡C-), stilbenes (Z=-CH=CH-), and biphenyls (Z = a carbon to carbon bond). Among examples of such biphenyl groups, wherein Z is a carbon to carbon bond i.e. a phenyl to phenyl bond, are 4-[4-(butyloxy)phenyl]benzoyl, 4-[4-(cyclobutylmethoxy)-phenyl]benzoyl, 4-[4-cyclopentylmethoxy)phenyl]benzoyl, 4-[4-(cyclohexylethoxy)-phenyl]benzoyl, 4-[4-(n-hexyloxy)-phenyl]benzoyl, 4-phenylbenzoyl, 4-[4-(11-amino-undecyloxy)-phenyl]benzoyl, 4-[4-(11-formamidoundecyloxy)phenyl]benzoyl, 4-[4-(isopentyloxy)phenyl]benzoyl, and the like. Examples of diphenylacetylene and stilbene acyl groups, R 2 , wherein Z is an acetylenic bond or an ethylene bond are 4-styrylbenzoyl, 4-(4-methoxystyryl)benzoyl, 4-(4-butyloxystyryl)benzoyl, 4-(phenylethynyl)benzoyl, 4-(4-ethoxyphenylethynyl)benzoyl, 4- (4-cyclohexyloxyphenylethynyl)benzoyl, and the like. Examples of such acyl groups wherein R 4 is represented by the formula -Y-R 6 include 4-[4-(phenylethynyl)phenyl]benzoyl, 4-[4-(phenylethynyl)-phenoxy]benzoyl, 4-[4-(hexynyl)phenyl]benzoyl, 4-[4-(styryl)phenoxy]benzoyl, 4-[4-(4-benzylphenylethynyl)-phenyl]benzoyl, 4-[4-[4-4-methylpiperidino)ethoxy]phenylethynyl]phenyl]benzoyl and like acyl groups. Such acyl groups wherein R 4 is represented by the formula -O-(CH 2 ) p' -W-R 5 form salts of the basic amino groups of the piperidine and piperazine heterocyclic groups with both organic and inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid and phosphoric acid and with organic acids such as the sulfonic acids, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, acetic acid, chloroacetic acid, trifluoroacetic acid, benzoic acid, isophthalic acid, salicylic acid, citric acid, malic acid, succinic acid, malonic acid and like acids. The following tables contain further examples of the cyclic peptides represented by the formula (1). Table 1 contains examples of cyclic peptides wherein the acyl group R 2 is of the formula The following Table 2 illustrates the compound of the formula (1) wherein R 2 is represented by the formula The acyl cyclohexapeptides represented by formula (1) exhibit antiparasitic activity, for example, they are especially active against the infectious fungi Candida albicans and Candida parapsilosis . They also exhibit significant activity against Aspergillus fumigatus . They are active both in vitro and in vivo and accordingly are useful in combating systemic fungal infections. The compounds of the invention also inhibit the growth of certain organisms primarily responsible for opportunistic infections in immunosuppressed individuals. For example the compounds of the invention inhibit the growth of Pneumocystis carinii the causative organism of pneumocystis pneumonia in AIDS sufferers. The antifungal activity of the compounds of the invention is determined in vitro in standard agar dilution tests and disc-diffusion tests wherein minimum inhibitory concentrations of the test compounds obtained. Standard in vivo tests in mice are used to determine the effective dose of the test compounds in controlling systemic fungal infections. Tables 4A-E below contain the minimum inhibitory concentrations (MIC) in micrograms per milliliter (mcg/ml) for compounds of the invention against Candida albicans and Candida parapsilosis, and for certain compounds, the effective dose, ED 50 , in mice. In Tables 4A-E, R'=CH 3 , R"=CH 3 , R'''=CH 3 , R y =OH, R 7 =OH and R 1 =H, In Tables 4A-D, R=OH, while in Table E, R=H. In Table 4C, R 2 is of the formula where Z is a carbon-carbon bond and R 4 is as indicated. R 4 MIC (mcg/ml) ED 50 (mg/ml) C.alb. C.parap. -C≡C-C 4 H 9 0.039 2.5 1.20 -C≡C-C 6 H 5 0.039 0.625 0.60 -C 6 H 5 0.078 10 1.3 The non-dideoxy compounds of the invention (formula (1) are prepared with the amino nuclei of the cyclic hexapeptides which are represented by the formula when R 2 is hydrogen. These amino nuclei are obtained from the known natural products by the known enzymatic deacylation by which the fatty acid side chains of the natural compounds are removed. For example, echinocandin B which can be represented by the formula (1) wherein R'=R''=R'''= methyl, R is OH, R y is hydroxy, R 1 is H, R 7 is OH, and R 2 is linoleoyl, is deacylated to provide the echinocandin B nucleus (R 2 =H) with the deacylase produced by the organism Actinoplanes utahensis as described by U.S. Patent Nos. 4,293,482 and 4,304,716. The known natural cyclic hexapeptides which are N-deacylated to provide the amino nuclei starting materials include echinocandin B (also known as A-30912A), aculeacin (palmitoyl side chain), tetrahydoechinocandin B (stearoyl side chain), mulundocandin (branched C 15 side chain), L-671,329 (C 16 branched side chain), S 31794/F1 (tetradecanoyl side chain), sporiofungin (C 15 branched side chain) and FR901379 (palmitoyl side chain). The amino nuclei obtained by the N-deacylation are then acylated by employing known amino acylation procedures to provide the N-acyl cyclic hexapeptides represented by the formula (1) wherein R 2 represents the acyl groups defined hereinabove. The acylating moiety is preferably an active ester of the carboxylic acid RCOOH such as the 2,4,5-trichlorophenyl ester. The R 2 COOH precursor acids are prepared by the hydrolysis of the nitrile R 2 CN or the ester R 2 COOC 1 -C 4 alk. These nitrile and ester intermediates are prepared by known methods. The alkoxy aromatic (ie. phenyl and biphenyl) compounds of Tables 9-10 are prepared by one of the two following procedures: A. The hydroxyaromatic compound (1 equivalent) is dissolved in acetonitrile (200-300 ml) and a base, such as potassium t-butoxide or potassium carbonate,(1-equivalent), is added. An alkyl bromide, iodide, or p-toluenesulfonate (1 equivalent) is then added and the solution is refluxed for 6 hours. The solvent is evaporated in vacuo and the residue is dissolved in ether and 2N sodium hydroxide. The ether layer is dried over magnesium sulfate and evaporated to give the alkoxyaromatic product. B. The hydroxyaromatic compound (1 equivalent), alkyl alcohol (1 equivalent), and triphenylphosphine (1 equivalent) are dissolved in tetrahydrofuran (200-300 ml) and diethylazodicarboxylate (1 equivalent) is added dropwise over 10 minutes at room temperature. After 17 hours the solvent is removed in vacuo and the residue is dissolved in ether. This organic layer is extracted with 2N sodium hydroxide solution, dried over magnesium sulfate, and evaporated to give a product which is crystallized from ether/pentane or, if the product contains a tertiary amine, the hydrochloride salt is formed and crystallized from methanol/ethyl acetate. The alkynyl and alkenyl aromatic compounds contained in Tables 11-14 are prepared by the following procedure: An aromatic bromide, iodide, or trifluoromethane-sulfonate (1 equivalent) is dissolved in acetonitrile (600 ml/0.1 mole of aromatic reactant) under a nitrogen atmosphere. An alkyne or alkene (1 equivalent), triethylamine (2 equivalents), palladium dichloride (0.05 equivalents), triphenylphosphine (0.1 equivalents), and cuprous iodide (0.025 equivalents) are added and the solution is refluxed for 17 hours. The solvent is removed in vacuo and the residue is slurried in ether (300 ml). Solids are removed by filtration and the filtrate is washed with 1N hydrochloric acid solution. The organic layer is dried over magnesium sulfate and evaporated to yield the product. The aromatic boronic acids listed in Table 15 were prepared by the following procedure: An aromatic halide (1 equivalent) is cooled to -78°C in tetrahydrofuran solvent. Butyl lithium (1.2 equivalents) is added. After 15 min triisopropyl borate (2 equivalents) is added and after 10 min of stirring the cooling bath is removed. When the reaction has warmed to room temperature water is added to quench the reaction followed by 1N HCl. The organic layer is removed under reduced pressure leaving a solid precipitate which is collected by filtration. This solid is washed with hexane leaving the pure boronic acid. The terphenyl esters listed in Table 16 were made in the following manner: An aromatic boronic acid (1 equivalent), methyl 4-iodobenzoate (1 equivalent), and potassium carbonate (1.5 equivalents) were mixed in a nitrogen-purged toluene solution. Alternatively, the trichloro phenyl ester of iodobenzoate my be used. Added tetrakis(triphenylphosphine)palladium (0.03 equivalents) and refluxed for 7 hrs. The solution was decanted to remove the potassium carbonate and reduced in vacuo. The residue was triturated with acetonitrile and the product solid was collected by filtration. The aromatic nitriles or carboxylate esters described in Tables 9-16 can be converted to carboxylic acids by one of the two following hydrolysis procedures: A. An aromatic nitrile is dissolved in ethanol and an excess of 50% sodium hydroxide solution and refluxed for 2 hours. Water is added until a solid precipitates. The precipitate is collected by filtration, added to dioxane and 6N hydrochloric acid solution and refluxed for 17 hours. Water is added and the carboxylic acid product crystallizes and is collected by filtration and dried under vacuum. B. A carboxylate methyl ester is dissolved in methanol, excess 2N sodium hydroxide solution is added and the solution is refluxed for 5 hours. The solution is made acidic with excess hydrochloric acid and water is added until a precipitate forms. The carboxylic acid is collected by filtration and dried under vacuum. The carboxylic acids are converted to 2,4,5-trichlorophenyl esters shown in Tables 18, 20 and 22-25 by the following general procedure: The aromatic acid (1 equivalent), 2,4,5-trichlorophenol (1 equivalent), and N,N'-dicyclohexylcarbodiimide (1 equivalent) are dissolved in methylene chloride. The mixture is stirred for 17 hours after which it is filtered. The filtrate is evaporated to dryness and the residue is dissolved in ether, filtered, and pentane is added until crystallization begins. The crystalline product is collected by filtration and dried under vacuum. The dideoxy compounds of formula (1) are prepared by removing the benzylic and aminal hydroxy groups. The process includes subjecting a non-dideoxy compound of formula (1) (wherein R 2 may be hydrogen or acyl) to a strong acid such as trichloroacetic acid, trifluoroacetic acid or borontrifluoride etherate with trifluoroacetic acid being preferred, and a reducing agent, such as sodium cyanoborohydride or triethylsilane, with triethylsilane being preferred. The reaction takes place at temperatures of between -5 and 70°C, and in a suitable solvent such as methylene chloride, chloroform or acetic acid, with dichloromethane being preferred. The acid should be present in an amount of 2 to 60 moles per mole of substrate, and the reducing agent should be present in an amount of 2 to 60 moles per mole of substrate. This process affords selective removal of the aminal and benzylic hydroxy groups. The compounds represented by the formula (1) have improved properties over the previously known N-acyl hexapeptide antifungals. For example, in general the compounds exhibit oral bioavailability, a property which is important for any systemic antifungal agent. Also, numerous N-acyl compounds of the formula (1) have enhanced antifungal activity and enhanced water solubility. Among the N-acyl hexapeptides represented by the formula (1) certain are preferred embodiments of the invention. The compounds wherein R 2 is a diphenyl acyl group wherein Z is a carbon to carbon bond and R 4 is -Y-R 6 and R 6 is C 1 -C 12 alkyl phenyl or substituted phenyl and Y is an acetylenic bond. Examples of preferred compounds of the above mentioned group include compounds wherein R 4 is 4-[4-(phenylethynyl)-phenyl]benzoyl and 4-[4-(n-butylethynyl)phenyl]benzoyl. Preferred cyclohexylpeptide compounds are represented by the formula 1 wherein R'=R''= methyl, R 1 is hydrogen and R 2 is a preferred acyl group as defined hereinabove. Table 26 is a list of the most preferred R 2 substituents, wherein R=R 7 =R y =OH; R'=R''= R'''=CH 3 ; and R 1 =H. The N-acylhexapeptides provided by this invention are useful in the treatment of fungal infections both systemic infections and skin infections. Accordingly this invention also provides a method for treating fungal infections in man and animals which comprises administering to said host an antifungally effective non-toxic amount of an N-acyl-cyclohexapeptide represented by the formula 1. A preferred antifungal method comprises administering an N-acylhexapeptide compound where, in formula 1, R'=R''= methyl, R 1 is hydrogen and R 2 is a preferred acyl group as defined hereinabove. The antifungal compound can be administered parenterally, e.g. i.m., i.p. or s.c., nasally, orally or can be applied topically for skin infections. The dose administered of course will vary depending on such factors as the nature and severity of the infection, the age and general health of the host and the tolerance of a particular host to the particular antifungal agent. The particular dose regimen likewise may vary according to such factors and may be given in a single daily dose or in multiple doses during the day. The regimen may last from about 2-3 days up to about 2-3 weeks or longer. This invention also provides pharmaceutical formulations useful for administering the antifungal compounds of the invention. These formulations comprise an N-acylhexapeptide represented by the formula 1 or a pharmaceutically acceptable, non-toxic salt thereof and a pharmaceutically acceptable carrier. For parenteral administration the formulation comprises a compound of the formula 1 and a physiologically acceptable diluent such as deionized water, physiological saline, 5% dextrose and other commonly used diluents. The formulation may contain a solubilizing agent such as a polyethylene glycol or polypropylene glycol or other known solubilizing agent. Such formulations may be made up in sterile vials containing the antifungal and excipient in a dry powder or lyophilized powder form. Prior to use, the physiologically acceptable diluent is added and the solution withdrawn via syringe for administration to the patient. For oral administration, the antifungal compound is filled into gelatin capsules or formed into tablets. Such tablets also contain a binding agent, a dispersant or other suitable excipients suitable for preparing a proper size tablet for the dosage and particular antifungal compound of the formula 1. For pediatric or geriatric use the antifungal compound may be formulated into a flavored liquid suspension, solution or emulsion. A preferred oral carrier system is lineolic acid, cremophor RH-60 and water and preferably in the amount (by volume) of 8% lineolic acid, 5% cremophor RH-60, and 87% sterile water. The compound is added to the system in an amount of 2.5 to 40 mg/ml. For topical use the antifungal compound can be formulated with a dry powder for application to the skin surface or it may be formulated in a liquid formulation comprising a solubilizing aqueous liquid or non-aqueous liquid, e.g., an alcohol or glycol. Such formulations are useful forms for use in the antifungal method provided herein. The N-acylcyclohexapeptides provided herein may be formulated as described above in unit dosage formulations comprising for injection between about 50 mg and about 500 mg per vial. For oral use gelatin capsules or tablets comprising between about 100 mg and about 500 mg per capsule or tablet can be provided. Preferred formulations of the invention comprises the active ingredient presented by the formula 1 wherein R'=R''= methyl, R 1 is hydrogen and R 2 is 4-[4-(phenylethynyl)-phenyl]benzoyl in gelatin capsules or as active ingredient the antifungal represented by the formula 1 wherein R'=R''= methyl, R 1 is hydrogen and R 2 is 4-[4-[2-(4-cyclohexyl-piperidino)ethoxy]phenyl]benzoyl or the hydrochloride salt form thereof in tablet or gelatin capsules. Further preferred formulations are those in which a preferred compound, as described above, is employed. In yet a further aspect of the present invention there is provided a method for treating patients suffering from Pneumocystis pneumonia. The method can be used prophylactically to prevent the onset of the infection which is caused by the organism Pneumocystis carinii. The N-acylcyclicpeptide can be administered parenterally, e.g. via intramuscular (i.m), intravenous (iv.) or intraperitoneal (i.p.) injection, or orally or by inhalation directly into the airways of the lungs. Preferably the cyclic peptide is administered via inhalation of an aerosol spray formulation of the compound. An effective amount of a cyclic peptide will be between about 3 mg/kg of patient body weight to about 100 mg/kg. The amount administered may be in a single daily dose or multiple doses e.g. two, three or four times daily throughout the treatment regimen. The amount of the individual doses, the route of delivery, the frequency of dosing and the term of therapy will vary according to such factors as the intensity and extent of infection, the age and general health of the patient, the response of the patient to therapy and how well the patient tolerates the drug. It is known that PCP infections in AIDS patients are highly refractory owing to the nature of the infection. For example, in severe, advanced infections the lumenal surface of the air passages becomes clogged with infectious matter and extensive parasite development occurs in lung tissue. A patient with an advanced infection will accordingly require higher doses for longer periods of time. In contrast, immune deficient patients who are not severely infected and who are susceptible to PCP can be treated with lower and less frequent prophylactic doses. The activity of the cyclicpeptide represented by the formula 1 is demonstrated in immunosuppressed rats. The tests were carried out in general as follows. One week after initiation of immunosuppression rats were inoculated intratracheally with parasites and maintained on immunosuppression for the remainder of the study. Prophylactic treatments began one day after parasite inoculation and therapeutic treatments began 3 or 4 weeks later after moderate PCP developed. Eight or ten animals were assigned to the following groups: those receiving test compound; non-treated Pneumocystis infected control animals; animals treated with trimethoprim-sulfamethoxazole (TMP-SMX); or non-treated, non-infected control animals. The efficacy of different treatments was evaluated by monitoring animal weights and survival during the studies and by determining the severity of PCP at necropsy. Stained impression smears of the lungs and stained lung homogenates were evaluated to determine the intensity of P . carinii infection. The immune deficient rats employed in the tests were prepared as follows. Female Lewis rats weighing from 120-140 g each were immune suppressed with methyl prednisolone acetate at a dose of 4 mg/100 g for the first week, 3 mg/100 g for the second week and continuing weekly thereafter at 2 mg/100 g. All rats, except for the non-infected control rats, were inoculated intratracheally with 0.1 ml to 0.2 ml of Dulbecco's Modified Eagle Media containing between >10 5 and 10 6 P . carinii (trophozoites, precysts and cysts) harvested from the lungs of heavily infected donor animals (infection scores of 6) and maintained as cryopreserved (liquid nitrogen) inocula. Rats were maintained on immune suppression and PCP was allowed to develop for 3 or 4 weeks before initiation of therapy with test compounds. Body weights were recorded weekly and rats were allocated into treatment groups such that each group had a similar distribution of percent weight loss among animals. Rats were treated with test compounds for 2 or 3 weeks and then were necropsied. For prophylaxis studies, administration of test compound was initiated one day after intratracheal inoculation of parasites and was continued until the rats were necropsied. Following the evaluation period for test compounds, the rats were necropsied and test results evaluated by Giemsa-stained, silver-methenamine stained impression smears and/or by silver-methenamine stained lung homogenate (see below). Necropsy was carried out as follows. The test rats were anesthetized with a mixture of ketamine hydrochloride and xylazine and then exsanguinated via the right atrium. Internal organs in the abdominal and thoracic cavities were examined for gross lesions. A small portion of lung tissue from the left lobe of each rat was used to make the impression smears described below. Giemsa-stained impression smears were evaluated to determine the total number of parasites (trophozoites, precysts, and cysts). Impression smears from rats in groups whose treatments exhibited some anti- Pneumocystis activity (as judged by infection scores from Giemsa-stained slides) and from rats in the control groups were also stained with methamine silver, a stain specific for the cyst wall of the organism. Impression smears were randomized, numbered, and then evaluated. The infection scores used were as follows: Score Basis O No parasites found 1 1 to 5 parasites/10 oil fields 2 ca 1 parasite/field 3 2-10 parasites/field 4 >10 but <100 parasites/field 5 >100 but <1,000 parasites/field A score of 6 was reserved for those infections with impression smears containing >1,000 organisms/field (too numerous to count). Giemsa-stained slides were examined microscopically using a final magnification of 1008X. Methenamine silver-stained slides were examined with a final magnification of 400X. Cysts in rat lung tissue were quantified as follows. A small portion of lung tissue from the left lobe of each rat was used to make impression smears as described above. The remainder of each lung was weighed, placed in a tube containing Hanks balanced salt solution (HBSS) (40X the lung weight) and homogenized using a Brinkman model tissue homogenizer. Two µl samples of the homogenized lung samples (1:4 dilution in HBSS) were placed in wells of teflon-coated, 12-well slides, stained with methenamine silver, and the number of cysts were scored as described above for the impression smears. The activity and efficacy of a preferred N-acylcyclohexapeptide in the test animals is presented below. The compound of the formula 1 wherein R'=R''= methyl, R 1 is hydrogen and R 2 is 4[(4-phenylethynyl)phenyl]benzoyl when administered as an aerosol solution at a concentration of 5 mg/ml for one hour, twice weekly for 5 weeks resulted in 90% reduction in P. carinii cysts in the lungs. When given orally at 10 mg/kg, bid for 3 weeks, the number of cysts in the lungs was reduced by >99% when compared with infected vehicle controls. When the preferred N-acylcyclicpeptides were administered orally and by intraperitoneal injection the compound was effective in clearing P . carinii cysts from the lungs of heavily infected rats. For example, when the compound was administered at 10 or 40 mg/kg, bid for 4, 8 or 12 days, the number of identifiable cysts in the lungs of heavily infected rats was reduced by >99%. Similar efficacy was observed when the compound was administered i.p. at 1 mg/kg. When tested orally for prophylactic activity, the preferred compound exhibited >99% cyst reduction in one of two studies when infected animals were dosed at 1 mg/kg and when given higher doses of 5 or 4 mg/kg. The following examples of compounds of the invention and the manner of their preparation further describe the present invention. N-Acylation of Cyclohexpeptide Nuclei The preparation of the derivatives of the A30912A nucleus was accomplished by the following general procedure, with Table 27 listing these derivatives. The A30912A nucleus and the 2,4,5-trichlorophenol ester are dissolved in dimethylformamide (25-50 ml) and stirred for 17-65 hours at room temperature. The solvent is removed in vacuo and the residue is slurried in ether and collected by filtration. The solid product is washed with methylene chloride and then dissolved in either methanol or acetonitrile/water (1:1 v/v). This solution is injected on a waters 600E semi-preparative chromatography system using a Rainin Dynamax-60A C 18 reverse-phase column. The column is eluted beginning with 20-40% aqueous acetonitrile and 0.5% monobasic ammonium phosphate (w/v) (monitored by UV at 230 nm and at a flow rate of 20 ml/min) until the unreacted A30912A nucleus is eluted and then deleting the buffer and eluting the product peak in aqueous acetonitrile. The fraction containing the product is evaporated in vacuo or lyophilized to provide the pure compound. The product may be analyzed by the same HPLC instrument using a Waters C 18 Micro Bondapak column and eluting with 40% aqueous acetonitrile containing 0.5% monobasic ammonium phosphate (w/v) at a 2 ml/min flow rate and monitoring the UV at 230 nm. The products may also be analyzed by fast atom bombardment mass spectrometry (FABMS). (In the compounds used, R'=R''=R'''=CH 3 , R=OH, R y =OH, R 1 =H, R 7 =OH, and R 2 is as defined). Compounds such as those listed in Table 27 could be further modified at the phenolic hydroxy to provide R 7 = -OPO 3 HNa as shown in Table 28. The procedure is as follows: The lipopeptide (1 equivalent) and tetrabenzylpyrophosphate (2 equivalents) were dissolved in dimethylformamide which had been dried over 13X molecular sieves. Lithium hydroxide monohydrate (5 equivalents) was added and the stirred solution was monitored by HPLC. After 0.5 hr and 1 hr more lithium hydroxide (5 equivalents) was added. Between 1 and 2 hrs. the reaction was quenched with glacial acetic acid, the solvent removed under vacuum, and the residue purified over a semi-preparative C18 reverse-phase column using an aqueous acetonitrile eluent. The purified product was dissolved in (1/1) acetic acid/water with sodium acetate (1 equivalent) and 10% Pd/C catalyst. The solution was placed under an atmosphere of hydrogen gas and stirred for 1 hr. After filtering to remove the catalyst, the solution was lyophilized to provide the pure final product. The purity was assessed by analytical HPLC and the product was analyzed by fast atom bombardment mass spectrometry (FABMS). Preparation of dideoxy cyclohexapeptide The preparation of the dideoxy compounds may be accomplished by the following procedure. To a suspension of a non-dideoxy cyclohexapeptide (formula (I) where R=OH and R 2 is hydrogen or acyl), in dichloromethane is added the reducing agent triethylsilane in dichloromethane. The solution is stirred and the volatile components are removed under reduced pressure and the residue triturated with diethyl ether. The compound is purified using HPLC, and the product lyophilized. Example Dideoxycilofungin To a suspension of cilofungin (10.00 g, 9.71 mmol) in dichloromethane (100 ml) was added a solution of triethylsilane (96 ml, 602 mmol) in dichloromethane (50 ml). Trifluoroacetic acid (46.4 ml, 602 mmol) was added as a solution in dichloromethane (50 ml) over 15 minutes. The solution was stirred at room temperature for two hours. The volatile reaction components were removed under reduced pressure and the residue triturated with diethyl ether. The compound was purified by reversed phase HPLC by means of a "Prep LC/System 500" unit (Waters Associates, Inc., Milford, Mass.) using a Prep Pak 500/C 18 Column (Waters Associates, Inc.) as the stationary phase. The column eluted with a gradient mobile phase using CH 3 CN/H 2 O (10:90 to 20:80 v/v) at 500 psi. The product containing fractions were pooled, evaporated under reduced pressure, and lyophilized from p-dioxane to yield dideoxycilofungin (6.66 g, 68.7%). FAB-MS: m/z calc. for C 49 H 72 N 7 O 15 , 998.5086; found, 998.512; UVλ(EtOH)nm(ε) 202.60(61012), 256.20(18569). A compound of the formula the preparation of which is discussed just prior to Table 27, can also be further modified at the phenolic hydroxy to provide R 7 =-OPO 3 HNa, as indicated in the two paragraphs prior to Table 28. The compound produced is as follows: The product was analyzed by FABMS (using Lit) to give a peak at 1226.4853 (calculated for C 58 H 74 N 7 O 20 PLi=1226.4886). Also, when analyzed by HPLC using a C18 reverse-phase column and eluting with 55% aqueous acetonitrile with 0.5% acetic acid at 2 ml/min and monitoring by UV at 280 nm, the compound had a retention time of 1.72 min.

Claims: A compound of the formula (1): wherein R' is hydrogen, methyl or NH 2 C(O)CH 2 -; R" and R"' are independently methyl or hydrogen; R and R y are independently hydroxy or hydrogen; R 1 is hydroxy, hydrogen or hydroxysulfonyloxy; R 7 is hydroxy, hydrogen, hydroxysulfonyloxy or phosphonooxy; and I) R 2 is a substituted benzoyl group represented by the formula wherein R 3 is quinolyl; or (II) R 2 is an acyl group represented by the formula wherein Z is -C≡C-, -CH=CH-, or a carbon to carbon bond; (A) R 4 is C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, C 3 -C 12 cycloalkoxy, naphthyl, pyridyl, thienyl, benzothienyl, quinolyl or phenyl; or (B) R 4 is phenyl substituted by amino, C 1 -C 12 alkylthio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 substituted alkyl, C 2 -C 12 substituted alkenyl, C 2 -C 12 substituted alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, phenyl, substituted phenyl, phenyl substituted with a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m and n are integers of from 2 to 4, and p is 0 or 1; or C) R 4 is phenyl substituted with C 1 -C 6 alkoxy substituted by fluoro, bromo, chloro or iodo; or D) R 4 is a group represented by the formula -Y-R 6 wherein Y is -C≡C- or -C=C-; and R 6 is C 1 -C 12 alkyl, C 1 -C 12 substituted alkyl; C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, phenyl, C 3 -C 12 cycloalkenyl, naphthyl, benzothiazolyl, thienyl, phenyl substituted by amino, C 1 -C 12 alkylthio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, -O-(CH 2 ) p' -W-R 5 wherein p' is an integer of from 2 to 4; W is pyrrolidino, piperidino or piperazino, and R 5 is hydrogen, C 1 -C 12 alkyl, C 3 -C 12 cycloalkyl, benzyl or C 3 -C 12 cycloalkylmethyl; or C 1 -C 6 alkoxy substituted by fluoro, bromo, iodo or chloro; or R 6 is a phenyl substituted by a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m, n and p are as defined above; or R 2 is an acyl group represented by the formula wherein Z is -C≡C- or -CH=CH-; A) R 4 is hydrogen, C 2 -C 12 alkynyl, C 2 -C 12 substituted alkynyl, C 1 -C 12 alkoxy; or B) R 4 is C 1 -C 12 alkoxy substituted with C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, C 2 -C 12 alkynyl, amino, C 1 -C 4 alkylamino, di-(C 1 -C 4 alkyl)amino, C 1 -C 12 alkanoylamino, phenyl substituted with a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m,n and p are as defined; or C) R 4 is C 1 -C 12 alkoxy substituted with a group of the formula wherein R 3 is C 1 -C 6 alkoxy optionally substituted with phenyl; or D) R 4 is a group represented by the formula -O-(CH 2 ) p' -W-R 5 wherein p', W and R 5 are as defmed; or IV) R 2 is a group having the formula wherein Y and R 6 are as defined above; or V) R 2 is naphthoyl substituted with R 4 wherein A) R 4 is C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, C 3 -C 12 cycloalkoxy, naphthyl, pyridyl, thienyl, benzothienyl, quinolyl or phenyl; or B) R 4 is phenyl substituted by amino, C 1 -C 12 alkylthio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 substituted alkyl, C 2 -C 12 substituted alkenyl, C 2 -C 12 substituted alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, phenyl, substituted phenyl, phenyl substituted with a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m, n and p are as defined; or C) R 4 is phenyl substituted with C 1 -C 6 alkoxy substituted by fluoro, bromo, chloro or iodo; or D) R 4 is a group represented by the formula -Y-R 6 wherein Y has the same meanings as defined above; and R 6 is C 1 -C 12 alkyl, C 1 -C 12 substituted alkyl; C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, phenyl, C 3 -C 12 cycloalkenyl, naphthyl, benzothiazolyl, thienyl, phenyl substituted by amino, C 1 -C 12 alkythio, halogen, C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, C 1 -C 12 alkoxy, trifluoromethyl, -O-(CH 2 ) p' -W-R 5 , or C 1 -C 6 alkoxy substituted by fluoro, bromo, iodo or chloro; or R 6 is a phenyl substituted by a polyoxa-alkyl group represented by the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) wherein m, n and p are as defined above; and the pharmaceutically acceptable non-toxic salts thereof. A compound according to claim 1 wherein R 1 is hydroxy or hydrogen and R 7 is hydroxy or hydrogen. A compound according to claim 1 or claim 2 wherein R', R" and R'" are methyl, R 1 is hydrogen, and R 7 and R y are OH. A compound according to any one of claims 1 to 3 wherein R 2 is of the formula wherein Z is a carbon to carbon bond; and R 4 is C 3 -C 7 cycloalkoxy; or R 4 is phenyl substituted by C 1 -C 12 alkoxy or phenyl substituted with a polyoxa-alkyl group of the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl); or R 4 is a group of the formula -Y-R 6 , wherein Y is -C≡C- or -C=C- and R 6 is C 1 -C 6 alkyl, phenyl, or phenyl substituted with a polyoxa-alkyl group of the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl). A compound according to any one of claims 1 to 3 wherein R 2 is of the formula wherein Z is -C≡C-; and R 4 is phenyl substituted by C 1 -C 12 alkoxy or phenyl substituted with a polyoxa-alkyl group of the formula -O-(CH 2 ) m -[O-(CH 2 ) n ] p -O-(C 1 -C 12 alkyl) or R 4 is a group of the formula -O-(CH 2 ) p' -W-R 5 wherein W is a piperidine group. A compound according to any one of claims 1 to 3 wherein R is hydrogen. A compound according to any one of claims 1 to 3 wherein R 2 is 4-[4-(phenylethynyl)phenyl]benzoyl or 4-[4-(n-butylethynyl)phenyl]beraoyl. A compound of the formula (1): wherein R' is hydrogen, methyl or NH 2 C(O)CH 2 -; R" and R"' are independently methyl or hydrogen; R and R y are independently hydroxy or hydrogen; R 1 is hydroxy, hydrogen, or hydroxysulfonyloxy; R 7 is hydroxy, hydrogen, hydroxysulfonyloxy or phosphonooxy; and I) R 2 is a group of the formula and pharmaceutically acceptable salts thereof. A compound according to claim 8 wherein R', R" and R"' are methyl, R 1 is hydrogen and R 7 and R y are hydroxy. A compound of the formula (1): wherein R' is hydrogen, methyl or NH 2 C(O)CH 2 -; R" is methyl or hydrogen; R is hydroxy or hydrogen; R 1 is hydroxy, hydrogen, or hydroxysulfonyloxy; R 7 is hydroxy, hydrogen, hydroxysulfonyloxy or phosphonooxy; R 2 is an acyl group represented by the formula wherein Z is -C≡C-, -CH=CH-, or a carbon to carbon bond; R 4 is C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, phenyl, phenyl substituted by amino, C 1 -C 12 alkythio, halogen, C 1 -C 12 alkyl, C 1 -C 12 alkoxy, trifluoromethyl, phenyl, or C 1 -C 6 alkoxy substituted by fluoro, bromo, chloro or iodo; or R 4 is C 3 -C 12 cycloalkoxy; or R 4 is a group represented by the formula -Y-R 6 wherein Y is -C≡C- or -CH=CH- and R 6 is C 1 -C 12 alkyl, C 1 -C 12 alkyl substituted by phenyl; C 3- C 12 cycloalkyl, phenyl, C 3- C 12 cycloalkenyl, naphthyl, benzthiazol-2-yl, or phenyl substituted by amino, C 1 -C 12 alkythio, halogen, C 1 -C 12 alkyl, C 1 -C 12 alkenyl. C 1 -C 12 alkoxy, trifluoromethyl, -O-(CH 2 ) p' -W-R 5 wherein p' is an integer of from 2 to 4; W is pyrrolidino, piperidino or piperazino, and R 5 is hydrogen, C 1 -C 12 alkyl, C 3 -C 12 cycloalkyl, benzyl or C 3 -C 12 cycloalkylmethyl; or C 1 -C 6 alkoxy substituted by fluoro, bromo, iodo or chloro; or R 2 is an acyl group represented by the formula wherein Z is -C≡C- or -CH=CH-; R 4 is hydrogen: R 4 is C 1 -C 12 alkoxy, C 1 -C 12 alkoxy substituted by C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, amino, C 1 -C 4 alkylamino, di-(C 1 -C 4 alkyl)amino, C 1 -C 12 alkanoylamino or a group of the formula wherein R 8 is C 1 -C 6 alkoxy optionally substituted with phenyl; or R 4 is a group represented by the formula -O-(CH 2 ) p' -W-R 5 or R 2 is a group selected from wherein Y and R 6 are as defined above; or R 2 is naphthoyl substituted with R 4 wherein R 4 is C 3 -C 12 cycloalkyl, C 7 -C 10 bicycloalkyl, C 7 -C 14 tricycloalkyl, phenyl, phenyl substituted by amino, C 1 -C 12 alkythio, halogen, C 1 -C 12 alkyl, C 1 -C 12 alkoxy, trifluoromethyl, phenyl, or C 1 -C 6 alkoxy substituted by fluoro, bromo, chloro or iodo; or R 4 is C 3 -C 12 cycloalkoxy; or R 4 is a group represented by the formula -Y-R 6 wherein Y has the same meanings as defined above and R 6 is C 1 -C 12 alkyl, C 1 -C 12 alkyl substituted by phenyl; C 3 -C 12 cycloalkyl, phenyl, C 3 -C 12 cycloalkenyl, naphthyl, benzthiazol-2-yl, or phenyl substituted by amino, C 1 -C 12 alkylthio, halogen, C 1 -C 12 alkyl, C 1 -C 12 alkenyl, C 1 -C 12 alkoxy, trifluoromethyl, -O-(CH 2 ) p' -W-R 5 , or C 1 -C 6 alkoxy substituted by fluoro, bromo, iodo or chloro; and the pharmaceutically acceptable non-toxic salts thereof. A compound according to claim 10 wherein R 1 is not hydroxysulfonyloxy and R 7 is not hydroxysulfonyloxy or phosphonooxy. A compound of the formula A compound of the formula A compound of the formula wherein R is -O(CH 2 ) 3 CH 3 , -O(CH 2 ) 4 CH 3 , -O(CH 2 ) 5 CH 3 , -O(CH 2 ) 2 O(CH 2 ) 3 CH 3 or -O(CH 2 ) 2 OC(CH 3 ) 3 . A compound according to claim 14 wherein R is -O(CH 2 ) 4 CH 3 . A compound according to any of claims 1-15 for use in inhibiting parasitic activity. A compound according to any one of claims 1-15 for use in inhibiting fungal activity. A compound according to any of claims 1-15 for use in inhibiting the growth of organisms responsible for opportunistic infections in immunosuppressed individuals. A compound according to any of claims 1-15 for use in inhibiting the growth of Pneumocystis carinii . A pharmaceutical formulation comprising a compound according to any of claims 1-15 and a suitable pharmaceutical carrier. A process for the preparation of a compound of the formula (1): wherein R' is hydrogen, methyl or NH 2 C(O)CH 2 -; R" and R"' is methyl or hydrogen; R is hydrogen; R y is hydroxy or hydrogen; R 1 is hydroxy, or hydrogen; R 7 is hydroxy, or hydrogen; and R 2 is hydrogen or acyl; comprising the step of subjecting a compound of formula (1) wherein R=OH, to a strong acid in the presence of a reducing agent, in a suitable solvent. A process for producing an N-acyl cyclic hexapeptide which process comprises acylating an amino nucleus of Echinocandin B with an active ester of a carboxylic acid represented by the formula wherein R is -O(CH 2 ) 3 CH 3 , -O(CH 2 ) 4 CH 3 , -O(CH 2 ) 5 CH 3 , -O(CH 2 ) 2 O(CH 2 ) 3 CH 3 or -O(CH 2 ) 2 OC(CH 3 ) 3 . A process for preparing a compound of the formula wherein R is -O(CH 2 ) 3 CH 3 , -O(CH 2 ) 4 CH 3 , -O(CH 2 ) 5 CH 3 , -O(CH 2 ) 2 O(CH 2 ) 3 CH 3 or -O(CH 2 ) 2 OC(CH 3 ) 3 which process comprises acylating an amino nucleus of Echinocandin B with an active ester of a carboxylic acid represented by the formula A process according to claim 22 or claim 23 wherein R is -O(CH 2 ) 4 CH 3 . A process according to any one of claims 22-24 wherein the active ester is a 2,4,5-trichlorophenyl ester. A process according to any one of claims 22-25 wherein the amine nucleus of Echinocandin B is obtained by N-deacylation of a naturally occurring cyclic hexapeptide. A process according to claims 26 wherein the naturally occurring cyclic hexapeptide is echinocandin B, tetrahydroechinocandin B, mulundocandin, L-671 329, S 31794/FI, sporiofungin or FR 901379.

Inventors: BURKHARDT FREDERICK JOSEPH, DEBONO MANUEL, NISSEN JEFFREY SCOTT, TURNER JR WILLIAM WILSON, BURKHARDT, FREDERICK JOSEPH, DEBONO, MANUEL, NISSEN, JEFFREY SCOTT, TURNER JR., WILLIAM WILSON
Applicants: LILLY CO ELI, ELI LILLY AND COMPANY
Application year: 1993
Main classification: C07K7
IPC codes: C07K1, A61K38, C07K7, A61P31, A01N43, C07K14, C07F9