WO1996009312A1

WO1996009312A1 - Antibiotic macrolides

Info

Publication number: WO1996009312A1
Application number: PCT/IB1995/000661
Authority: WO
Inventors: Burton H. Jaynes; Kristin M. Lundy
Original assignee: Pfizer Inc.
Priority date: 1994-09-22
Filing date: 1995-08-17
Publication date: 1996-03-28
Also published as: AU3121095A; BR9504119A; IL115312A0; CO4410328A1

Abstract

The present invention relates to derivatives of 16-membered ring macrolide antibiotics rosaramicin, repromicin, 5-mycaminosyltylonolide, desmycosin, lactenocin, O-demethyllactenocin, cirramycin A1, and 23-deoxymycaminosyltylonolide, which are useful against bacterial and mycoplasmic pathogens in animals. The present invention is also directed to pharmaceutical compositions comprising such derivatives and use of such derivatives in treating bacterial and mycoplasmic infections in animals. Pharmaceutically acceptable salts thereof are disclosed. In formulae (I) or (II) m is 2 or 3.

Description

ANTIBIOTIC ACROLIDES

Background of the Invention

This invention is concerned with new antibiotics. In particular, this invention relates to compounds which are derivatives of the macrolide antibiotics rosaramicin, repromicin, 5-mycaminosyltylonolide, desmycosin, lactenocin, O-demethyllactenocin, cirramycin A^ and 23-deoxymycaminosyttylonolide; to the pharmaceutically-acceptable acid addition salts of such derivatives; to methods of using such derivatives in the treatment of illnesses in animals caused by bacterial and mycoplasmic pathogens; and to pharmaceutical compositions useful therefor. The term "animals" includes mammals, fish and birds.

There are numerous agents known to combat bacterial infectious diseases in animals, but for many specific diseases the current agents of choice leave much to be desired, in some instances the agents may not persist long enough in the host and, therefore, require frequent dosing to maintain therapeutically effective blood and/or tissue levels. For meat producing animals (cattle, poultry, sheep and swine) this will require considerable labor intensive animal handling which is costly to the producer. In other cases, the agent may be poorly tolerated or even toxic to the host at therapeutically effective doses. Agents with increased potency, a longer half-life, an increased therapeutic index and a broader spectrum of antibacterial activity as well as agents with greater oral absorption would improve the scope of animal diseases that could be more effectively treated. Thus, the need for new antibacterial and anti- mycoplasmic agents with improved properties endures.

Diseases of particular concern are: bovine respiratory disease, the principal causative bacterial pathogens of which are Pasteurella haemolvtica. P. multocida and Haemophilus somnus: pasteurellosis in swine, goats, sheep and poultry (P. multocida): swine pleuropneumonia (Actinobacillus pleuropneumoniae): swine streptococcus infections (Streptococcus syjs); and for all of the above mentioned hosts, infections by Mycoplasma spp. Derivatives of tylosin and its related macrolides have been shown to be effective against infections in poultry, cattle and pigs caused by certain gram-positive and gram- negative bacteria: Kirst et al., U.S. Patent 4,920,103; Tao et al., U.S. Patent 4,921 ,947; Kirst et al., U.K. Patent Application GB 2135670A. Other antibiotic macrolides have been claimed in co-pending U. S. Applications: Serial No. 08/193,316 filed February 8, 1994 and Serial No. 08/145,456 filed October 29, 1993.

Disclosure of the Invention This invention is concerned with new antibiotics which are derivatives of the macrolides repromicin, rosaramicin, 5-mycaminosyrtylonolide, desmycosin, lactenocin, O-demethyllactenocin, cirramycin A,, and 23-deoxymycaminosyrtylonolide and to the acid addition salts of such derivatives. These new antibiotics have enhanced potency against bacterial pathogens over the parent compounds and are active against mycoplasmic pathogens.

The compounds of the present invention and their pharmaceutically-acceptable salts are of the formula (I) or (II)

or

and the pharmaceutically acceptable salts thereof wherein m is 2 or 3; Z¹ is H, OH or mycarosyloxy;

Q is selected from the group consisting of H, OH, fluoro, chloro, bromo, iodo, OX¹,

azetidin-1-yl, pyrrolidin-1-yl, piperidin-1-yl, 3,3-dimethylpiperidin-1-yl, hexahydro- azepin-1-yl,octahydroazocin-1-yl,octahydroindol-1-yl, 1 ,3,3a,4,7,7a-hexahydroisoindol- 2-yl, decahydroquinol-1-yl, decahydroisoquinol-2-yl, 1 ,2,3,4-tetrahydroisoquinol-2-yl, 1 ,2,3,6-tetrahydropyridin-l-yl, 4-alkylpiperazin-1-yl having 1 to 4 carbons in the alkyl portion, morpholino, 2,6-dimethy!morpholin-4-yl, thiomo holino, and -NR¹R², wherein R¹ and R² are independently selected from the group consisting of H, alkyl having 1 to 4 carbons, hydroxyalkyl having 2 to 4 carbons, cycloalkyl having 3 to 8 carbons, alkenyl having 3 or 4 carbons, alkoxyalkyl having 1 to 4 carbons in the alkoxy portion and 2 to 4 carbons in the alkyl portion and alkoxyalkoxyalkyl having 1 to 4 carbons in each of the alkoxy portions and 2 to

4 carbons in the alkyl portion; and X¹ is selected from the group consisting of optionally substituted alkyl having 1 to 4 carbons, optionally substituted cycloalkyl having 4 to 8 carbon atoms, and an optionally substituted aryl, aralkyl or heteroaryl group selected from the group consisting of phenyl, benzyl, pyridinyl, quinolinyl, isoquinolinyl, quinazolinyl, pyrimidinyl, imidazolyl, oxazolyl, thiazolyl, benzimidazolyl, indolyl, benzoxazolyl and benzthiazolyl; wherein the optionally substituted alkyl and optionally substituted cycloalkyl can be substituted with 1 or 2 substituents independently selected from the group consisting of hydroxy, amino, N-alkylamino having 1 to 4 carbons, N,N-dialkylamino having a total of 2 to 6 carbons and alkoxy having 1 to 4 carbons; and where the optionally substituted aryl, aralkyl and heteroaryl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of alkyl having 1 to 4 carbons, fluoro, chloro, bromo, acetyl, amino, nitro, cyano, trifluoromethyl, N-alkylamino having 1 to 4 carbons, N,N-dialkylamino having a total of 2 to 6 carbons, carboxyl, carboalkoxy having 1 to 4 carbons, carboxamido, sulfonamido, hydroxyalkyl having 1 to 4 carbons, aminoalkyl having 1 to 4 carbons, N-alkylaminoalkyl having 1 to 4 carbons in each of the alkyl portions, and N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 1 to 4 carbons in the alkyl portion;

T is

-N(Z⁴)((CH₂)_fl-N(Z⁸)(CO-X³-Z⁵)), or -N(Z⁴)((CH₂)_g-N(Z⁶)(SO₂-Z^s)); X² is aminoalkyl having 2 to 6 carbons, hydroxyalkyl having 2 to 4 carbons, N- alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion, N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, -CO-X'-Z⁵ or -SO_j-Z⁵;

X³ is O or NH; a is 1 or 2; b is 1 or 2; g is 2, 3 or 4; Z² is independently selected from the group consisting of hydrogen, (C₁-C₄)alkyl, optionally substituted alkyl having 2 to 6 carbons, optionally substituted cycloalkyl having 3 to 8 carbons, aminoalkyl having 2 to 6 carbons, hydroxyalkyl having 2 to 6 carbons, N-alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, N.N-dialkyiaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, benzyl, alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion, an aminoacyl group, a dipeptidyl group, -(CH₂)_β-morpholino, -(CH₂)_β-piperidino, -(CH₂)_β-pyrrolidino, -(CH₂)_β-azetidin-1-yl, and -(CH₂)_β-hexahydroazepin-1-yl; wherein e is 2, 3 or 4; the optionally substituted alkyl and optionally substituted cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of hydroxy, cyano, fluoro, trifluoromethyl, optionally substituted amino, optionally substituted N- alkylamino having 1 to 4 carbons, N,N-dialkylamino having a total of 2 to 6 carbons, N-(hydroxyalkyl)amino having 2 to 4 carbons, N,N- bis(hydroxyalkyl)amino wherein each alkyl portion has 2 to 4 carbons, alkoxy having 1 to 4 carbons, alkoxycarbαnyl having 1 to 4 carbons in the alkoxy portion, N,N-dialkylaminoalkoxy having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkoxy portion, alkoxyalkoxy having 1 to 4 carbons in each of the alkoxy portions, aikoxyalkoxyalkoxy having 1 to 4 carbons in each of the alkoxy portions,

wherein the optionally substituted amino and the optionally substituted N-alkylamino are each independently optionally substituted with an aminoacyl group or a dipeptidyl group; ] is 2, 3, or 4; R³ and R⁴ are independently selected from hydrogen and alkyl having 1 to 4 carbons; or R³ and R⁴ are taken together with the nitrogen to which they are attached and form a saturated or unsaturated ring having 4 to 6 carbon atoms, morpholino or piperazino; A is NH, S, N-(C C₄)alkyl, N-(aminoacyl group), or N-(dipeptidyl group);

B\ B², and B³ are each independently selected from the group consisting of hydrogen, (C₁-C₄)alkyl, an aminoacyl group and a dipeptidyl group; Y¹ is selected from the group consisting of C, CH, CH₂, N and

NH; n is 0, 1 or 2;

R^s is alkyl having 1 to 4 carbons or -CO₂-loweralkyl; R⁶ is hydrogen or alkyl having 1 to 4 carbons; R⁷ is selected from the group consisting of H, alkyl having 1 to

4 carbons, hydroxy, alkoxy having 1 to 3 carbons, amino, N- alkylamino having 1 to 4 carbons and N,N-dialkylamino having a total of 2 to 6 carbons; or R⁶ and R⁷ are taken together and form an oxo group; Z³ is -[(CH₂)_d-X⁴]_q-(CH₂)_r-N(Z⁷)₂ wherein d is 2, 3 or 4; q is 1 , 2 or 3; r is 2, 3 or

4; X⁴ is S or O; and Z⁷ for each occurrence is independently selected from the group consisting of an aminoacyl group, dipeptidyl group and the same group of substituents as is defined hereinbelow for Z⁴, Z⁵ and Z⁶; Z⁴, Z⁵ and Z⁶ are each independently selected from the group consisting of hydrogen, methyl, optionally substituted alkyl having 2 to 6 carbons, optionally substituted cycloalkyl having 3 to 8 carbons, optionally substituted phenyl, aminoalkyl having 2 to 6 carbons, hydroxyalkyl having 2 to 6 carbons, N- alkyiaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, benzyl, alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion, -(CH₂)_f-morpholino, -(CH₂),-piperidino, -(CH₂),-pyrrolidino, -(CH₂)_f-azetidin-1-yl, -(CH₂)_f-phthalimido and -(CH₂)_f-hexahydroazepin-1-yl and provided that Z⁵ is hydrogen only when X³ is NH; wherein f is 2, 3 or 4; the optionally substituted phenyl is optionally substituted with 1 or 2 substituents independently selected from the group consisting of alkyl having 1 to 4 carbons, fluoro, chloro, bromo, acetyl, amino, nitro, cyano, trifluoromethyl, N-alkylamino having 1 to 4 carbons, N,N-dialkyl-amino having a total of 2 to 6 carbons, -NH-CO-CH₃, carboxyl, carboalkoxy having 1 to 4 carbons, carboxamido, sulfonamido, hydroxyalkyl having 1 to 4 carbons, aminoalkyl having 1 to 4 carbons, N-alkylaminoalkyl having 1 to 4 carbons in each of the alkyl portions, and N,N- dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 1 to 4 carbons in the alkyl portion; wherein the optionally substituted alkyl and the optionally substituted cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of hydroxy, cyano, fluoro, trifluoromethyl, amino, N-alkylamino having 1 to 4 carbons, phthalimido, N.N-dialkylamino having a total of 2 to 6 carbons, N- (hydroxyalkyl)amino having 2 to 4 carbons, N,N-bis(hydroxyalkyl)amino wherein each alkyl portion has 2 to 4 carbons, alkoxy having 1 to 4 carbons, alkoxycarbonyl having 1 to 4 carbons in the alkoxy portion,

N,N-dialkylaminoalkoxy having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkoxy portion, alkoxyalkoxy having 1 to 4 carbons in each of the alkoxy portions, alkoxyalkoxyalkoxy having 1 to 4 carbons in each of the alkoxy portions,

-C- _R9

R⁸ and R^β are independently selected from hydrogen and alkyl having 1 to 4 carbons; or R⁸ and R⁹ are taken together with the nitrogen to which they are attached and form a saturated or unsaturated ring having 4 to 6 carbon atoms, morpholino or piperazino;

E is NH, S, or N-^-CJalkyl; Y² is selected from the group consisting of C, CH, CH₂, N and

NH; t is 0, 1 or 2;

R¹⁰ is alkyl having 1 to 4 carbons or -CO₂-loweralkyl;

R¹¹ is hydrogen or alkyl having 1 to 4 carbons; R¹² is selected from the group consisting of H, alkyl having 1 to

4 carbons, hydroxy, alkoxy having 1 to 3 carbons, amino, N- alkylamino having 1 to 4 carbons and N,N-dialkylamino having a total of 2 to 6 carbons; or R¹¹ and R¹² are taken together and form an oxo group; and, for each occurrence of the aminoacyl group and dipeptidyl group, the aminoacyl group and the aminoacyl groups of the dipeptidyl group are independently selected from the group consisting of the D- or L- form, when applicable, of alanyl, arginyl, asparagyl, aspartyl acid, cysteinyl, cystyl, glutamyl acid, glutamyl, glycyl, histidyl, hydroxylysyl, hydroxyprolyl, isoleucyl, leucyl, lysyl, methionyl, phenylalanyl, prolyl, seryl, threonyl, tryptophyl, tyrosyl, valyl, β-alanyl, β-lysyl, N,N-dimethylglycyl, σ.σ-dimethylglycyl, σ- aminobutyryl, 4-hydroxyphenylglycyl, phenylglycyl, σ, -diaminobutyryl, ornithyl, homoseryl, bicyl, N,N-diethyl-β-alanyl, N,N-dimethyl- -aminobutyryl and sarcosyl, provided that N,N-dimethylglycyl, bicyl, N,N-diethyl-β-alanyl or N,N-dimethyl- - aminobutyryl can only be the terminal aminoacyl when in a dipeptidyl group.

The term "loweralkyl" denotes an alkyl having 1 to 4 carbons. The term "alkyl" is meant to encompass both straight chain and branched alky Is.

Those skilled in the art will recognize that some of the compounds of the present invention possess stereochemical centers. In those cases where stereochemical centers are present it is understood that all of the stereoisomers are within the scope of this application. The amino acyl groups are derivatives of the corresponding amino acids and are well known in the art. The following D- or L- amino acids, where applicable, are used to derive the amino acyl groups of this invention: aianine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, histidine, hydroxylysine, hydroxyproline, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophane, tyrosine, valine, β-alanine, β-lysine, N,N- dimethylglycine, σ.σ-dimethylglycine, σ-aminobutyric acid, 4-hydroxyphenylglycine, phenylglycine, σ.σ-diaminobutyric acid, ornithine, homoserine, bicine, N,N-diethyl-β- alanine, N,N-dimethyl- -aminobutyric acid, and sarcosine.

The dipeptidyl groups comprise derivatives of any possible combination of two of the amino acids listed hereinabove which have been coupled by conventional peptide synthesis methods well known to those skilled in the art.

A preferred group of compounds are those compounds having the formula (I) or the pharmaceutically acceptable salts thereof wherein m and T are as defined above for formula (I); Z¹ is hydrogen; and Q is hydrogen or OH. A more preferred group of compounds are those compounds having the formula

(I) or the pharmaceutically acceptable salts thereof wherein m and T are as defined above for formula (I); Z¹ is hydrogen; and Q is hydrogen. Another more preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q is hydrogen; T is -NfZ'Z³), -N(Z )(SO₂-Z⁵), -N(Z*)(CO-X^s-Z⁸) or -N(Z⁴)((CH₂)_g-N(Z^β)(SO₂-Z⁵)). Still another more preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q is hydrogen; T is -N(Z*)(SO₂-Z⁵), where Z⁴ is N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion and Z⁵ is alkyl having 2 to 6 carbons, -(CH₂)_f-phthalimido where f is 2, 3 or 4, or phenyl substituted with -NH-CO-CH₃.

An even more preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q is hydrogen; T is -N(Z⁴)(CO-X³-Z⁵) where Z⁴ is N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, X³ is O and Z⁵ is alkyl having 2 to 6 carbons or N-alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion.

Another even more preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q is hydrogen; T is -N(Z⁴)(CO-X³-Z⁵), where Z⁴ is N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, X³ is NH and Z⁵ is alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion.

Still another even more preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q is hydrogen; T is -N(Z )((CH₂)_g-N(Z⁵)(SO₂-Z⁵)), where Z⁴ is hydroxyalkyl having 2 to 6 carbons, g is 3, Z⁶ is hydrogen and Z⁵ is alkyl having 2 to 6 carbons.

Yet still another even more preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q is hydrogen; T is -N(Z²Z³) where Z² is hydrogen or (C₁-C₄)alkyl and Z³ is as defined above for formula (I).

A most preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q is hydrogen; T is -N^Z³) where Z² is hydrogen or (C C₄)alkyl and Z³ is -[(CH₂)_d-X⁴]_q-(CH₂)_r-N(Z⁷)₂ where X⁴ is O; d and r are each 2; Z⁷ is hydrogen; and q is 1.

Another most preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q

is hydrogen; T is . where a, b and X² are as defined above for formula

(I)-

Further, the most preferred group of compounds are those compounds of the formula (I) or the pharmaceutically acceptable salts thereof wherein Z¹ is hydrogen; Q y — "*««>* is hydrogen; T is -N N-χ² _> where a and b are each 1 or 2 and X² is aminoalkyl

having 2 to 6 carbons, N-alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, or N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion. Of the immediately foregoing most preferred group of compounds, the more preferred compounds are those compounds wherein a and b are each 1 and X² is aminoalkyl having 2 to 6 carbons.

The compounds of the present invention, having the formula (I) or (II), as defined above, are readily and generally prepared by reductive amination reactions of the appropriate macrolide, rosaramicin, repromicin, 5-mycaminosyltylonolide, desmycosin, lactenocin, O-demethyllactenosin, cirramycin A,, or 23- deoxymycaminosyltylonolide, with an amine, optionally followed by conversion to the acid addition salt as shown in the methods of the Examples hereinbelow, in methods analogous thereto and by the methods described immediately below.

Derivatization of the parent macrolide at the C-23 position is carried out according to the method well known to those skilled in the art and as described in J. Antibiotics, 40(6), pp. 823-842, 1987, the contents of which are incorporated herein by reference.

The starting macrolide rosaramicin is produced and isolated according to the method described by Wagman et al. in Journal of Antibiotics, Vol. XXV, No. 11 , pp.641- 6/09312 PCΪ7IB95/00661

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646, November 1972. Repromicin is synthesized from rosaramicin using the method taught by Ganguly et al. in U.S. Patent 3,975,372. Desmycosin, lactenocin, O-demethyllactenocin and 23-deoxymycaminosyltylonolide are produced and isolated according to the method described in Journal of Antibiotics, 35(12), pp. 1675-1682, 1982. Cirramycin A,, is produced and isolated according to the method described in Journal of Antibiotics, 22, p. 61 , 1969. The contents of the above references are incorporated herein by reference. All other starting materials and reagents required for the synthesis of the compounds of the present invention are readily available commercially or can be prepared according methods known in the literature. Some of the compounds described in this invention require the formation of ureas and sulfonamides from a starting amine. Ureas are formed using standard conditions, such as reaction of the amine in an inert solvent (e.g., toluene or CH₂CI₂) with an isocyanate. An external base such as triethylamine may be used. Some isocyanates are commercially available or can be prepared by the reaction of a primary amine with phosgene or an equivalent (e.g., triphosgene). Other methods for isocyanate formation are suitable as well, such as Hofmann, Curtius, Lossen, and Schmidt rearrangements from carboxylic acid derivatives. Sulfonamides are most readily formed by reaction of an amine with a sulfonyl chloride, usually done in an inert solvent such as DMF with a base such as sodium carbonate.

The compounds of this invention wherein T is where a, b and X²

are as defined above for formulae (I) and (II), are synthesized according to the following procedure. The C-20 aldehyde of a series of 16-membered macrolides is coupled with a variety of amines by reductive amination to form secondary and tertiary amines at C-20. For example, repromicin, an amine (usually about 1.5 equivalents), and acetic acid are stirred in a reaction-inert solvent such as methylene chloride for about 30 to 60 mins. After cooling to about 0°C, powdered sodium sulfate (about 10 eq) and sodium triacetoxyborohydride, about 1.1 equivalents, are added and the reaction solution is stirred at ambient temperature for about 1 to 12 hours. The desired C-20 amino macrolide derivative is then isolated by standard techniques well known to those skilled in the art, such as extraction, column chromatography or crystallization. 96/09312 PCMB95/00661

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The antibacterial activity of the compounds of the present invention against bacterial pathogens is demonstrated by the compound's ability to inhibit growth of

Pasteurella multocida and/or Pasteurella haemolvtica. The following procedures are typical assays. Assay I is utilized to test for activity against Pasteurella multocida and Assay II is utilized to test for activity against Pasteurella haemolvtica.

Assay I (P. multocida) This assay is based on the liquid dilution method in microliter format. A single colony of P. multocida (strain 59A067) is inoculated into 5 ml of brain heart infusion (BHI) broth. The test compounds are prepared by solubiiizing 1 mg of the compound in 125 //I of dimethylsulfoxide (DMSO). Dilutions of the test compound are prepared using uninoculated BHI broth. The concentrations of the test compound used range from 200 /g/ml to 0.098 /g/ml by two-fold serial dilutions. The P. multocida inoculated BHI is diluted with uninoculated BHI broth to make a 10⁴ cell suspension per 200 //I. The BHI cell suspensions are mixed with respective serial dilutions of the test compound, and incubated at 37°C for 18 hours. The minimum inhibitory concentration (MIC) is equal to the concentration of the compound exhibiting 100% inhibition of growth of P. multocida as determined by comparison with an uninoculated control.

Assay II (P. haemolvtica) This assay is based on the agar dilution method using a Steers Replicator. Two to five colonies isolated from an agar plate are inoculated into BHI broth and incubated overnight at 37°C with shaking (200 rpm). The next morning, 300 /I of the fully grown P. haemolvtica preculture is inoculated into 3 ml of fresh BHI broth and is incubated at 37° C with shaking (200 rpm). The appropriate amounts of the test compounds are dissolved in ethanol and a series of two-fold serial dilutions are prepared. Two ml of the respective serial dilution is mixed with 18 ml of molten BHI agar and solidified. When the inoculated P. haemolvtica culture reaches 0.5 McFarland standard density, about 5 μ\ of the P. haemolvtica culture is inoculated onto BHI agar plates containing the various concentrations of the test compound using a Steers Replicator and incubated for 18 hours at 37°C. Initial concentrations of the test compound range from 100-200 //g/ml. The MIC is equal to the concentration of the test compound exhibiting 100% inhibition of growth of P. haemolvtica as determined by comparison with an uninoculated control. The in vivo activity of the compounds of formula (I) or (II) can be determined by conventional animal protection studies well known to those skilled in the art, usually carried out in mice.

Mice are allotted to cages (10 per cage) upon their arrival, and allowed to acclimate for a minimum of 48 hours before being used. Animals are inoculated with 0.5 ml of a 3 x 10³ CFU/ml bacterial suspension (P. multocida strain 59A006) intraperitoneally. Each experiment has at least 3 non-medicated control groups including one infected with 0.1X challenge dose and two infected with 1X challenge dose; a 10X challenge data group may also be used. Generally, all mice in a given study can be challenged within 30-90 minutes, especially if a repeating syringe (such as a Cornwall^® syringe) is used to administer the challenge. Thirty minutes after challenging has begun, the first compound treatment is given. It may be necessary for a second person to begin compound dosing if all of the animals have not been challenged at the end of 30 minutes. The routes of administration are subcutaneous or per os. Subcutaneous doses are administered into the loose skin in the back of the neck whereas oral doses are given by means of a feeding needle. In both cases, a volume of 0.2 ml is used per mouse. Compounds are administered 30 minutes, 4 hours, and 24 hours after challenge. A control compound of known efficacy administered by the same route is included in each test. Animals are observed daily, and the number of survivors in each group is recorded. The P. multocida model monitoring continues for 96 hours (four days) post challenge.

The PD_jjo is a calculated dose at which the compound tested protects 50% of a group of mice from mortality due to the bacterial infection which would be lethal in the absence of drug treatment. To implement the methods of this invention, an effective dose of a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof is administered to a susceptible or infected animal by parenteral (i.v., i.m. or s.c), oral or topical route. The effective dose will vary with the severity of the disease, and the age, weight and condition of the animal. However, the daily dose will usually range from about 0.25 to about 150 mg/kg, preferably from about 0.25 to about 25 mg/kg.

A suitable vehicle for administering the dose parenterally is a solution of the compound in sterile water, or a solution of the compound in a solvent comprising at least 50% water and a pharmaceutically acceptable cosolvent or cosolvents such as methanol, ethanol, isopropyl alcohol, propyiene glycol, glycerol, carbonate esters like diethyl carbonate, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and 1 -methyl-2-pyrτolidinone. Suspensions are also suitable vehicles for administering the compounds of this invention. The suspending medium can be, for example, aqueous carboxymethyl cellulose, inert oils such as peanut oil, highly refined mineral oils and aqueous polyvinylpyrrolidone. Suitable physiologically acceptable adjuvants may be necessary to maintain the compound in suspension. These adjuvants may be chosen from among thickeners such as carboxymethyl cellulose, polyvinylpyrrolidone, gelatin, and the alginates. Surfactants are also useful as suspending agents. These surfactants include: lethicin, alkylphenol polyethylene oxide adducts, naphthalenesulfonates, alkylbenzenesulfonates and polyoxyethylene sorbitan esters. Agents affecting surface tension can also help in making useful suspensions. Such agents include silicone anti-foams, sorbitol, and sugars. For intravenous use the total concentration of solutes should be controlled to render the preparation isotonic. Thus, in a further aspect, the invention provides pharmaceutical compositions comprising a compound of the formula (I) or (II), or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or diluent.

This invention also provides methods of treating a bacterial infection or a mycoplasmic infection in an animal in need thereof, which method comprises administering to said animal a bacterial or mycoplasmic treating amount of a compound of the formula (I) or (II), or a pharmaceutically acceptable salt thereof.

The present invention is illustrated by the following examples, but is not limited to the details thereof. High Performance Liquid Chromatography (HPLC) retention times of the products of this invention are determined on a Zorbax RX^β, 5 micron C8 column (4.6 mm ID x 15 cm length) from Dupont (available from Mac-Mod Analytical Inc., 127 Commons Court, Chadds Ford, PA 19317 1-800-441-7508). A 45:55 (vol:vol) mixture of acetonitrile to aqueous 50 millimolar ammonium acetate is used as the eluant. The column temperature is maintained at 40°C and the flow rate is 1.0 ml per minute. Samples are dissolved in the eluant (2 mg/ml) and are injected (70 I) into a Hewlett- Packard 1090 high performance liquid chromatography instrument; peaks corresponding to the sample input are detected by ultraviolet spectroscopy at either 254 or 280 nm. EXAMPLE 1 (Method A) 20-ι4-(2-Aminoethyl)piperazin-1-vπ-20-deoxo-repromicin Repromicin (150 mg, 0.265 mmol) was added to a stirred solution of 2-f-BOC- aminoethyl-1 -piperazine (2 eq, 126 mg) in 3 ml methylene chloride at about 0°C. Acetic acid (0.076 ml, 5 eq) was added and the reaction mixture was stirred for about 1 hr at about 0°C. Powdered sodium sulfate (376 mg, 10 eq) was added followed by 1.1 eq of sodium triacetoxyborohydride (62 mg) after about 10 min. The reaction was stirred for about 2 hr while warming slowly to ambient temperature and then filtered through a pad of Celrte^® with vacuum to remove solids. The organic solution was partitioned between methylene chloride and saturated sodium bicarbonate solution. Organics were washed with brine, dried over

filtered and concentrated under reduced pressure. The BOC protected-amine products were purified by flash column chromatography using 5% MeOH in CH₂CI₂ with 0.5% NH₄OH to afford 190 mg (92%) of 20-[4-(2-f-BOC-aminoethy1)piperazin-1-yl]-20-deoxo-repromicin.

Alternatively, a mixture of mono-BOC-protected 2-aminoethyl-1-piperazines, prepared with one equivalent of either BOC-ON or di-f-butyl dicarbonate in methylene chloride, was used in the reductive amination described above with an excess of repromicin to afford a mixture of the BOC-protected macrolide products. This mixture is more easily separated than either the protected triamine starting materials or the mixture of deprotected macrolide products following the reaction with TFA, as described below.

The BOC-protected macrolide derivative was then deprotected by the following procedure. Trifluoroacetic acid (5 ml) was added to an approximately 0°C solution of the macrolide (1.8 g, 2.3 mmoles) in 25 ml methylene chloride. The solution was allowed to warm to ambient temperature while stirring overnight. The reaction solution was concentrated under reduced pressure and then partitioned between methylene chloride and an aqueous solution at pH 6. The solutions were separated with the desired product remaining in the aqueous phase. The aqueous phase was then basified with saturated aqueous sodium bicarbonate solution to pH 7.5, 8.5, and 10 and extracted after each basification. Each of the organic solutions was washed with brine and concentrated under reduced pressure. Extractions from solutions at pH 7.5 and above provided nearly clean product which could be purified further, if desired, by flash chromatography (95:5:0.5 CH₂CI₂:MeOH:NH₄OH). In this way 1.2 g of the title compound was prepared as the free base (78 %). MS LSIMS: 679; HPLC RT: 5.30 mins.

EXAMPLE 2 (Method B)

20-f4-(2-Dimethylaminoethyl)piperazin-1-yl1-20-deoxo-repromicin

20-[4-(2-Aminoethyl)piperazin-1-yl]-20-deoxo-repromicin was prepared as described above in Example 1. The macrolide (200 mg, 0.294 mmol) was dissolved in

5 ml CH₃CN and then added to a stirring buffered aqueous formaldehyde solution (NaOAc3H₂O, 241 mg, 2.95 mmol, 10 eq; HOAc, 0.168 ml, 2.95 mmol, 10 eq; aqueous

CH₂O, 0.662 ml, 8.84 mmol, 30 eq; and 4 ml H₂O). The solution was stirred at ambient temperature for about 1 hr, cooled to about 0°C, and sodium cyanoborohydride (55 mg, 0.884 mmol, 3.0 eq) was added in two portions. After stirring for about 2.5 hr at room temperature the solution was concentrated in vacuo and then azeotroped twice with water before partitioning between CH₂CI₂ and a saturated aqueous sodium bicarbonate solution. The organic solution was washed with brine, dried over

filtered and then concentrated under reduced pressure. The white foamy solid was purified by flash chromatography with 10% MeOH in CH₂CI₂ with 0.5% NH₄OH to provide 142 mg (69%) of 20-[4-(2-dimethylaminoethyl)piperazin-1-yl]-20-deoxo- repromicin. MS LSIMS: 707; HPLC RT: 7.08 mins.

Example 3 20-^r2-(Aminoethoxy)ethylamino1-20-deoxorepromicin Starting with 1.13 g of repromicin (2 mmol), 1.42 g of 2,2'-oxybis(ethylamine) dihydrochloride (8 mmol), 0.57 mL of acetic acid (10 mmol), and 424 mg of sodium triacetoxyborohydride (2 mmol), the title compound was prepared using the method described in Preparation 1. To work up, the reaction mixture was filtered, the filtrate was diluted with CH₂CI₂, washed with aqueous saturated NaHCO₃, and dried over Na_jSO^ Filtration, evaporation, and chromatography over silica gel (10% MeOH in CH₂CI₂ with 0.5% NH₄OH, increased to 15% MeOH) provided 356 mg of product (27%). MS LSIMS 654. Example 4 (Method C) 20-fN-3-(Dimethylamino)propyl-N-(ethylsulfonvπamino1-20-deoxorepromicin To a solution of 500 mg (0.77 mmol) of 20-[3-(dimethylamino)propylamino]-20- deoxorepromicin (prepared in Preparation 1) in DMF (3 mL) at 0°C was added 244 mg (2.3 mmol) of sodium carbonate. After having been stirred for about 10 min, ethanesulfonyl chloride (0.08 mL, 0.8 mmol) was added dropwise and the mixture was stirred for about 3 hr in an ice bath and then stored overnight in a freezer (-5°C). DMF was removed by vacuum distillation and the residue was partitioned between CH₂CI₂ and saturated aqueous NaHCO₃. The aqueous layer was separated and extracted twice with CH₂CI₂; the combined organic layers then were dried over NaSO₄. Filtration and concentration provided a foam which was purified by flash chromatography (5 to 10% MeOH/CH₂CI₂ with 0.1% NH₄OH) to provide 234 mg of title compound (41%). MS LSIMS 744. Example 5

(Method D) 20-f1-(3-dimethylaminopropyl)-3-isopropyl1ureido-20-deoxorepromicin To a solution of 326 mg (0.50 mmol) of 20-[3-(dimethylamino)propylamino]-20- deoxorepromicin (Preparation 1) in 5 mL CH₂CI₂ at room temperature was added neat isopropyl isocyanate (0.05 mL, 0.50 mmol). TLC indicated the reaction to be complete after about 30 min. The reaction solution was evaporated and chromatographed (10% MeOH/CH₂CI₂ with 0.4% NH₄OH) to provide 224 mg (61%) of the title compound. MS LSIMS 737.

Example 6 20-f1-(3-dimethylaminopropyll-3-(2-methylamino)ethyl1ureido-20-deoxorepromicin

To a solution of N-methylethylenediamine (3.00 g, 40.5 mmol) in 50 mL of

CH₂CI₂ at about 5°C was added dropwise a solution of BOC-ON (9.97 g, 40.5 mmol) in 15 mL of CH₂CI₂. The yellow solution was maintained at about 0-5°C for about 1.5 hr and then washed 3x with aqueous 1N HCI. The combined aqueous layers were extracted with ether, brought to pH 14 with 6M NaOH, and extracted 3x with CH₂CI₂.

The combined organic layers were dried over Na^O^ filtered, evaporated, and chromatographed (10 to 15% MeOH/CH₂CI₂ with 0.5% NH₄OH) to provide 2.66 g (38%) of a primary amine. Later fractions contained 1.00 g of the regioisomeric BOC- protected secondary amine.

(Method E)

To a solution of the BOC-protected primary amine (0.42 g, 2.4 mmol) in 10 mL toluene was added a solution of triphosgene (240 mg, 0.8 mmol) in 10 mL toluene at room temperature. Triethylamine (0.33 mL, 4.8 mmol) was added and the solution was heated to about 95°C for about 6 hr. After cooling to room temperature, the mixture was filtered through Celite and to the filtrate was added 400 mg (0.61 mmol) 20- [3-

(dimethylamino)propylamino]-20-deoxorepromicin (Preparation 1). After about 2 days at room temperature, the reaction was worked up and purified as in Method D to yield

52 mg (10%) of a BOC-protected analog, which was deprotected with TFA as described in Preparation 2 to give 40 mg (91%) of the title compound. MS LSIMS 752.

Examples 7-10 The following compounds having the general formula shown below were synthesized analogously to the designated preparation method.

Preparation 1 20-r3-(Dimethylamino)propylamino1-20-deoxorepromicin To 5 g (8.85 mmol) of repromicin in 75 mL of CH₂CI₂ was added 3- (dimethylamino)propylamine (1.17 mL, 9.29 mmol), acetic acid (2.53 mL, 44.25 mmol) and powdered anhydrous sodium sulfate (12.57 g, 88.5 mmol). The mixture was allowed to stir for about 1 hour at room temperature and then was heated to reflux for about 2.5 hours. The mixture was cooled to about 0°C, treated with sodium triacetoxyborohydride (3.66 g, 9.29 mmol) and stirred at about 0°C for 1 hour when TLC analysis (89:10:2 - CHCI₃:MeOH:NH₄OH) indicated complete consumption of starting material. The reaction mixture was filtered to remove solids and the filtrate was washed with water to remove the desired product. The pH of the aqueous layer was adjusted to 9 and extracted with CH₂CI₂. After drying with Nβ_jSO,,, the solvent was removed under vacuum to give the desired material as a white foam.

Preparation 2 20-rN-(3-Aminopropylι-N-(2-hvdroxyethyl)aminol-20-deoxorepromicin

To a solution of N-(2-hydroxyethyl)-1 ,3-propanediamine (5.00 g, 42.3 mmol) in 50 mL of CH₂CI₂ at about 0°C was added BOC-ON (10.42 g, 42.3 mmol). Stirring was continued at about 0°C for about 2 hr at which time TLC indicated the reaction to be complete. The reaction mixture was concentrated to a yellow syrup and flash chromatographed over silica gel (10 to 20% MeOH/CH₂CI₂ with 0.2% NH₄OH). Appropriate fractions were pooled and evaporated to yield 7.66 g of mono-BOC intermediate (83% yield).

To a solution of this intermediate (2.89 g, 13.3 mmol) and repromicin (5.00 g, 8.8 mmol) in 100 mL of ethyl acetate at about 70°C was added formic acid (0.38 mL, 10.0 mmol). The cloudy reaction mixture was stirred at about 70°C for about 10 hr and then room temperature overnight. The mixture was diluted with ethyl acetate and washed with aqueous saturated NaHCO₃ and brine. The organic layer was dried over MgSO₄, filtered, evaporated, and chromatographed over silica gel (7% MeOH/CH₂CI₂ with 0.1% NH₄OH) to provide some clean and mixed fractions. Clean fractions were collected to provide 1.82 g (27%) of a BOC-protected analog. To a solution of this intermediate (1.82 g, 2.37 mmol) in 5 mL CH₂CI₂ at about 0°C was added 2.5 mL of trifluoroacetic acid. After stirring overnight, the solution was warmed to room temperature and another 1 mL of TFA was added. After about 15 min, solvent was removed by in vacuo. The residue was adjusted to pH 8.5 by careful addition of aqueous saturated NaHCO₃, which was then extracted three times with CH₂CI₂. The combined organic layers were dried over Na₂SO , filtered, and concentrated to afford 1.75 g of title compound as a yellow foam. The product was used as is for further reactions.

Claims

CLAIMSWe claim:

1. A compound of formula (I) or (II)

or

Q-

azetidin-1-yl, pyrτolidin-1-yl, piperidin-1-yl, 3,3-dimethylpiperidin-1-yl, hexahydro- azepin-1-yl,octahydroazocin-1-yl,octahydroindol-1-yl,1 ,3,3a,4,7,7a-hexahydroisoindol-

2-yl, decahydroquinoM-yl, decahydroisoquinol-2-yl, 1 ,2,3,4-tetrahydroisoquinol-2-yl,

1 ,2,3,6-tetrahydropyridin-l-yl, 4-alkylpiperazin-1 -yl having 1 to 4 carbons in the alkyl portion, morpholino, 2,6-dimethylmorpholin-4-yl, thiomo holino, and -NR¹R², wherein R¹ and R² are independently selected from the group consisting of H, alkyl having 1 to 4 carbons, hydroxyalkyl having 2 to 4 carbons, cycloalkyl having 3 to 8 carbons, alkenyl having 3 or 4 carbons, alkoxyalkyl having 1 to 4 carbons in the alkoxy portion and 2 to 4 carbons in the alkyl portion and alkoxyalkoxyalkyl having 1 to 4 carbons in each of the alkoxy portions and 2 to 4 carbons in the alkyl portion; and

X¹ is selected from the group consisting of optionally substituted alkyl having 1 to 4 carbons, optionally substituted cycloalkyl having 4 to 8 carbon atoms, and an optionally substituted aryl, aralkyl or heteroaryl group selected from the group consisting of phenyl, benzyl, pyridinyl, quinolinyl, isoquinolinyl, quinazolinyl, pyrimidinyl, imidazolyl, oxazolyl, thiazolyl, benzimidazolyl, indolyl, benzoxazolyl and benzthiazolyl; wherein the optionally substituted alkyl and optionally substituted cycloalkyl can be substituted with 1 or 2 substituents independently selected from the group consisting of hydroxy, amino, N-alkylamino having 1 to 4 carbons, N,N-dialkylamino having a total of 2 to 6 carbons and alkoxy having 1 to 4 carbons; and where the optionally substituted aryl, aralkyl and heteroaryl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of alkyl having 1 to 4 carbons, fluoro, chloro, bromo, acetyl, amino, nitro, cyano, trifluoromethyl, N-alkylamino having 1 to 4 carbons, N,N-dialkylamino having a total of 2 to 6 carbons, carboxyl, carboalkoxy having 1 to 4 carbons, carboxamido, sulfonamido, hydroxyalkyl having 1 to 4 carbons, aminoalkyl having 1 to 4 carbons, N-alkylaminoalkyl having 1 to 4 carbons in each of the alkyl portions, and N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 1 to 4 carbons in the alkyl portion;

-N(Z⁴)((CH₂)_fl-N(Z^β)(CO-X³-Z⁵)), or -N(Z⁴)((CH₂)_fl-N(Z^β)(SO₂-Z⁵));

X² is aminoalkyl having 2 to 6 carbons, hydroxyalkyl having 2 to 4 carbons, N- alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion, N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, -CO-X^Z⁵ or -SO_j-Z⁵; X³ is O or NH; a is 1 or 2; b is 1 or 2; g is 2, 3 or 4;

Z² is independently selected from the group consisting of hydrogen, (C,-C₄)alkyl, optionally substituted alkyl having 2 to 6 carbons, optionally substituted cycloalkyl having 3 to 8 carbons, aminoalkyl having 2 to 6 carbons, hydroxyalkyl having 2 to 6 carbons, N-alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, N,N-dialkyiaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, benzyl, alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion, an aminoacyl group, a dipeptidyl group,

-(CH₂)_β-moφholino, -(CH₂)_β-piperidino, -(CH₂)_β-pyrrolidino, -(CH₂)_β-azetidin-1-yl, and -(CH₂)_β-hexahydroazepin-1-yl; wherein e is 2, 3 or 4; the optionally substituted alkyl and optionally substituted cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of hydroxy, cyano, fluoro, trifluoromethyl, optionally substituted amino, optionally substituted N- alkylamino having 1 to 4 carbons, N.N-dialkylamino having a total of 2 to 6 carbons, N-(hydroxyalkyl)amino having 2 to 4 carbons, N,N- bis(hydroxyalkyl)amino wherein each alkyl portion has 2 to 4 carbons, alkoxy having 1 to 4 carbons, alkoxycarbonyl having 1 to 4 carbons in the alkoxy portion, N,N-dialkylaminoalkoxy having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkoxy portion, alkoxyalkoxy having 1 to 4 carbons in each of the alkoxy portions, alkoxyalkoxyaikoxy having 1 to 4 carbons in each of the alkoxy portions,

wherein the optionally substituted amino and the optionally substituted N-alkylamino are each independently optionally substituted with an aminoacyl group or a dipeptidyl group;

15 j is 2, 3, or 4;

R³ and R⁴ are independently selected from hydrogen and alkyl having 1 to 4 carbons; or R³ and R⁴ are taken together with the nitrogen to which they are attached and form a saturated or unsaturated ring having 4

20 to 6 carbon atoms, morpholino or piperazino;

A is NH, S, N-(C₁-C₄)alkyl, N-(aminoacyl group), or N-(dipeptidyl group); B¹, B², and B³ are each independently selected from the group consisting of hydrogen, (C₁-C₄)alkyl, an aminoacyl group and a dipeptidyl group;

Y¹ is selected from the group consisting of C, CH, CH₂, N and NH; n is 0, 1 or 2;

R⁵ is alkyl having 1 to 4 carbons or -CO₂-loweralkyl; R⁶ is hydrogen or alkyl having 1 to 4 carbons; R⁷ is selected from the group consisting of H, alkyl having 1 to 4 carbons, hydroxy, alkoxy having 1 to 3 carbons, amino, N- alkylamino having 1 to 4 carbons and N,N-dialkylamino having a total of 2 to 6 carbons; or R⁶ and R⁷ are taken together and form an oxo group; Z³ is -[(CH₂)_d-X ]_q-(CH₂)_r-N(Z⁷)₂ wherein d is 2, 3 or 4; q is 1 , 2 or 3; r is 2, 3 or 4; X⁴ is S or O; and Z⁷ for each occurrence is independently selected from the group consisting of an aminoacyl group, dipeptidyl group and the same group of substituents as is defined hereinbelow for Z⁴, Z⁵ and Z⁶; Z⁴, Z⁵ and Z⁶ are each independently selected from the group consisting of hydrogen, methyl, optionally substituted alkyl having 2 to 6 carbons, optionally substituted cycloalkyl having 3 to 8 carbons, optionally substituted phenyl, aminoalkyl having 2 to 6 carbons, hydroxyalkyl having 2 to 6 carbons, N- alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, N.N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, benzyl, alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion, -(CH₂)_f-morpholino, -(CH₂)_f-piperidino, -(CH₂)_f-pyrτolidino, -(CH₂)_f-azetidin-1-yl, -(CH₂)_f-phthalimido and -(CH₂),-hexahydroazepin-1-yl and provided that Z⁵ is hydrogen only when X³ is NH; wherein f is 2, 3 or 4; the optionally substituted phenyl is optionally substituted with 1 or 2 substituents independently selected from the group consisting of alkyl having 1 to 4 carbons, fluoro, chloro, bromo, acetyl, amino, nitro, cyano, trifluoromethyl, N-alkylamino having 1 to 4 carbons, N,N-dialkyl-amino having a total of 2 to 6 carbons, -NH-CO-CH₃, carboxyl, carboalkoxy having 1 to 4 carbons, carboxamido, sulfonamido, hydroxyalkyl having 1 to 4 carbons, aminoalkyl having 1 to 4 carbons, N-alkylaminoalkyl having 1 to 4 carbons in each of the alkyl portions, and N,N- dialkylaminoalkyi having a total of 2 to 6 carbons in the dialkylamino portion and 1 to 4 carbons in the alkyl portion; wherein the optionally substituted alkyl and the optionally substituted cycloalkyl groups are optionally substituted with 1 or 2 substituents independently selected from the group consisting of hydroxy, cyano, fluoro, trifluoromethyl, amino, N-alkylamino having 1 to 4 carbons, phthalimido, N,N-dialkylamino having a total of 2 to 6 carbons, N- (hydroxyalkyl)amino having 2 to 4 carbons, N,N-bis(hydroxyalkyl)amino wherein each alkyl portion has 2 to 4 carbons, alkoxy having 1 to 4 carbons, alkoxycarbonyl having 1 to 4 carbons in the alkoxy portion, N,N-dialkylaminoalkoxy having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkoxy portion, alkoxyalkoxy having 1 to 4 carbons in each of the alkoxy portions, alkoxyalkoxyaikoxy having 1 to 4 carbons in each of the alkoxy portions,

-C- <_R9

-_*C\

R⁸ and R⁹ are independently selected from hydrogen and alkyl having 1 to 4 carbons; or R⁸ and R⁹ are taken together with the nitrogen to which they are attached and form a saturated or unsaturated ring having 4 to 6 carbon atoms, morpholino or piperazino;

E is NH, S, or N-(C,-C₄)alkyl;

Y² is selected from the group consisting of C, CH, CH₂, N and NH; t is 0, 1 or 2;

R¹⁰ is alkyl having 1 to 4 carbons or -CO₂-loweralkyl;

R¹¹ is hydrogen or alkyl having 1 to 4 carbons;

R¹² is selected from the group consisting of H, alkyl having 1 to 4 carbons, hydroxy, alkoxy having 1 to 3 carbons, amino, N- alkylamino having 1 to 4 carbons and N,N-dialkylamino having a total of 2 to 6 carbons; or R¹¹ and R¹² are taken together and form an oxo group; and, for each occurrence of the aminoacyl group and dipeptidyl group, the aminoacyl group and the aminoacyl groups of the dipeptidyl group are independently selected from the group consisting of the D- or L- form, when applicable, of alanyl, arginyl, asparagyl, aspartyl acid, cysteinyl, cystyl, glutamyl acid, glutamyl, glycyl, histidyl, hydroxylysyl, hydroxyprolyl, isoleucyl, leucyl, lysyl, methionyl, phenylalanyl, prolyl, seryl, threonyl, tryptophyl, tyrosyl, valyl, β-alanyl, β-lysyl, N,N-dimethylglycyl, σ,σ-dimethylglycyl, a- aminobutyryl, 4-hydroxyphenylglycyl, phenylglycyl, σ, -diaminobutyryl, omithyl, homoseryl, bicyl, N,N-diethyl-β-alanyl, N,N-dimethyl- -aminobutyryl and sarcosyl, provided that N,N-dimethylglycyl, bicyl, N,N-diethyl-β-alanyl or N,N-dimethyl- - aminobutyryl can only be the terminal aminoacyl when in a dipeptidyl group. PCMB95/00661

-30-

2. A compound or a pharmaceutically acceptable salt thereof according to claim 1 having the formula (I) wherein Z¹ is hydrogen and Q is hydrogen or OH.

3. A compound or a pharmaceutically acceptable salt thereof according to claim 2 wherein Q is hydrogen.

4. A compound or a pharmaceutically acceptable salt thereof according to claim 3 wherein T is -N(Z²Z³), -N(Z )(SO₂-Z⁵), -N(Z )(CO-X³-Z⁵) or -N(Z⁴)((CH₂)_fl-N(Z^β)(SO₂-Z⁵)).

5. A compound or a pharmaceutically acceptable salt thereof according to claim 4 wherein T is -N(Z )(SO₂-Z⁵), where Z⁴ is N.N-dialkyiaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion and Z⁵ is alkyl having 2 to 6 carbons, -(CH₂),-phthalimido or phenyl substituted with -NH-CO-CH₃.

6. A compound or a pharmaceutically acceptable salt thereof according to claim 4 wherein T is -N(Z⁴)(CO-X³-Z⁵) where Z⁴ is N.N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, X³ is O and Z⁵ is alkyl having 2 to 6 carbons or N-alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion.

7. A compound or a pharmaceutically acceptable salt thereof according to claim 4 wherein T is -N(Z⁴)(CO-X³-Z⁵), where Z⁴ is N,N-dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion, X³ is NH and Z⁵ is alkoxyalkyl having 2 to 4 carbons in the alkyl portion and 1 to 4 carbons in the alkoxy portion.

8. A compound or a pharmaceutically acceptable salt thereof according to claim 4 wherein T is -N(Z )((CH₂)_β-N(Z⁸)(SO₂-Z⁵)), where Z⁴ is hydroxyalkyl having 2 to 6 carbons, g is 3, Z⁸ is hydrogen and Z⁵ is alkyl having 2 to 6 carbons.

9. A compound or a pharmaceutically acceptable salt thereof according to claim 4 wherein T is -N(Z²Z³) where Z² is hydrogen or (C₁-C₄)alkyl.

10. A compound or a pharmaceutically acceptable salt thereof according to claim 9 wherein Z³ is -[(CH₂)_d-X ]_q-(CH₂)_r-N(Z⁷)₂ where X⁴ is O; d and r are each 2; Z⁷ is hydrogen; and q is 1.

11. A compound or a pharmaceutically acceptable salt thereof according to

claim 3 wherein T is ■

12. A compound or a pharmaceutically acceptable salt thereof according to claim 11 wherein X² is aminoalkyl having 2 to 6 carbons, N-alkylaminoalkyl having 1 to 4 carbons in the alkylamino portion and 2 to 4 carbons in the alkyl portion, or N,N- dialkylaminoalkyl having a total of 2 to 6 carbons in the dialkylamino portion and 2 to 4 carbons in the alkyl portion.

13. A compound or a pharmaceutically acceptable salt thereof according to claim 12 wherein a and b are each 1 and X² is aminoalkyl having 2 to 6 carbons.

14. A pharmaceutical composition comprising a compound of claim 1 or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent.

15. A method of treating a bacterial infection in an animal in need thereof which comprises administering to said animal a bacterial treating amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof.

16. A method of treating a mycoplasmic infection in an animal in need thereof which comprises administering to said animal a mycoplasmic treating amount of claim 1 or a pharmaceutically acceptable salt thereof.