Abstract: Antibiotic A41030, a complex of 7 individual factors, is produced by submerged, aerobic fermentation of new Streptomyces virginiae NRRL 12525, and Streptomyces virginiae NRRL 15156. The antiobiotic factors are separated and possess antibacterial activity against Staphylococcus and Streptococcus species which are penicillin resistant. In addition, the antibiotic factors have shown inhibition of Streptococcus pneumonia Park I. The complex and the individual factors enhance feed efficiency in ruminant animals, and are growth promoters in chickens and swine, and are especially valuable in milk production in dairy cattle.

Abstract: 20-Dihydro-20-deoxy-23-de(mycinosyloxy)tylosin (20-deoxo-DMOT), specified 2'-acyl ester derivatives, and their acid addition salts are useful intermediates and antibacterial agents. Methods of preparing 20-deoxo-DMOT and 5-O-mycaminosyltylactone by fermentation of Streptomyces fradiae ATCC 31733 are included.

Abstract: A-21978C cyclic peptides of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, an amino-protecting group , 8-methyldecanoyl, 10-methylundecanoyl, 10-methyldodecanoyl, the specific C.sub.10 -alkanoyl group of A-21978C factor C.sub.0 and the specific C.sub.12 -alkanoyl groups of A-21978C factors C.sub.4 and C.sub.5 ; R.sup.1 and R.sup.2 are, independently, hydrogen or an amino-protecting group, and salts thereof, are prepared by enzymatic deacylation of an antibiotic selected from A-21978C complex, A-21978C factors C.sub.0, C.sub.1, C.sub.2, C.sub.3, C.sub.4 and C.sub.5 and blocked A-21978C complex and factors C.sub.0, C.sub.1, C.sub.2, C.sub.3, C.sub.4 and C.sub.5, using an enzyme produced by the Actinoplanaceae, preferably by Actinoplanes utahensis. The A-21978C cyclic peptides and salts thereof are useful intermediates to prepare new semi-synthetic antibacterial agents.

Abstract: Improved bioconverting strain of Streptomyces thermotolerans useful in preparing tylosin esters and new antibacterial macrocin or lactenocin ester derivatives of the formula: ##STR1## wherein R is formyl or hydroxymethyl; R.sup.1 is hydrogen, acetyl or propionyl; R.sup.2 is hydrogen or ##STR2## and R.sup.3 is hydrogen, acetyl, propionyl, n-butyryl or isovaleryl; provided that one of R.sup.1 or R.sup.3 must be other than hydrogen.

Abstract: Method of preparing compounds of formula 1: ##STR1## by oxidative deamination of a glycopeptide antibiotic of formula 2: ##STR2## the antibiotic being selected from A35512 factors A, B, C, E and H, A35512B pseudoaglycone, actaplanin factors A, B.sub.1, B.sub.2, B.sub.3, C.sub.1a, C.sub.2a, C.sub.3, D.sub.1, D.sub.2, E.sub.1, G, K, L, M, N and O, actaplanin pseudoaglycone, A41030 factors A, B, C, D, E, F and G, A47934, ristocetin A and ristocetin A pseudoaglycone, novel compounds and compositions and methods of increasing feed-utilization efficiency in animals are provided.

Abstract: 1-Oxa-beta-lactam antibiotics of the formula ##STR1## are broad spectrum antibiotics especially useful in the treatment of infections attributable to the gram-negative microorganisms such as Pseudomonas or are intermediates to such antibiotics.

Abstract: An improved method of preparing 23-monoester derivatives of 5-O-mycaminosyl tylonolide (OMT) and demycinosyltylosin (DMT) is provided. This method comprises esterifying the antibiotic with an acylating agent in the presence of an external base, such as pyridine or 2,4,6-collidine, until acylation of the 23-hydroxyl group is substantially complete, and separating the 23-monoester derivative. 23-Monoester derivatives of OMT and DMT are useful antibiotics and/or intermediates to antibiotics.

Abstract: 2'"-O-demethylmacrocin (DOMM) which has the formula: ##STR1## 20-dihydro-DOMM, 2'"-O-demethyllactenocin (DOML), 20-dihydro-DOML, specified acyl ester derivatives, and their acid addition salts are useful antibacterial agents.

Abstract: A-21978C cyclic peptides of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, an amino-protecting group, 8-methyldecanoyl, 10-methylundecanoyl, 10-methyldodecanoyl, the specific C.sub.10 -alkanoyl group of A-21978C factor C.sub.0 and the specific C.sub.12 -alkanoyl groups of A-21978C factors C.sub.4 and C.sub.5 ; R.sup.1 and R.sup.2 are, independently, hydrogen or an amino-protecting group, and salts thereof, are prepared by enzymatic deacylation of an antibiotic selected from A-21978C complex, A-21978C factors C.sub.0, C.sub.1, C.sub.2, C.sub.3, C.sub.4 amd C.sub.5 and blocked A-21978C complex and factors C.sub.0, C.sub.1, C.sub.2, C.sub.3, C.sub.4 and C.sub.5, using an enzyme produced by the Actinoplanaceae, preferably by Actinoplanes utahensis. The A-21978C cyclic peptides and salts thereof are useful intermediates to prepare new semi-synthetic antibacterial agents.

Abstract: Antibiotic A53868 factor A, which is N.sup.2 -glycyl-N-(2-methylene-2-phosphonoethyl)leucinamide, and the formula: ##STR1## and the salts thereof, which are useful as antibiotics or as intermediates to antibiotics; methods of preparing A53868 factor A by fermentation of Streptomyces luridus; and the microorganism S. luridus NRRL 15101.

Abstract: Zinc salts are used to effect the regio-selective acylation and alkylation of the 1-amino group of 4-O-substituted-2-deoxystreptamine-containing aminoglycosides. The 1-N-substituted derivatives of apramycin, 3'-hydroxyapramycin, certain .alpha. or .beta.-(lower alkyl)aprosaminides and certain .alpha. or .beta.-(substituted lower alkyl)-aprosaminides are new. The 1-N-substituted-4-O-substituted-2-deoxystreptamine aminoglycosides produced by the process of this invention are antibacterial agents.

Abstract: C-20- and C-23-Modified macrolide derivatives of demycinosyltylocin (DMT), 5-O-mycaminosyltylonolide (OMT) 23-de(mycinosyloxy)tylosin, 23-deoxy-OMT, 20-dihydro-20-deoxy-DMT and 20-dihydro-20-deoxy-OMT are useful antibiotics or intermediates to antibiotics.

Abstract: Antibiotic A53868 factor A, which is N.sup.2 -glycyl-N-(2-methylene-2-phosphonoethyl)leucinamide, and the formula: ##STR1## and the salts thereof, which are useful as antibiotics or as intermediates to antibiotics; methods of preparing A53868 factor A by fermentation of Streptomyces luridus; and the microorganism S. luridus NRRL 15101.

Abstract: C-23-Modified derivatives of 5-O-mycaminosyl-tylonolide (OMT) of the formula: ##STR1## wherein R is chloro, fluoro, --S--R.sup.4, azido, --NHR.sup.5, pyridinium, or --OSO.sub.2 CF.sub.3 ;R.sup.1 is hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl or optionally substituted benzoyl, phenylacetyl, phenylpropionyl, phenoxyacetyl or phenylthioacetyl;R.sup.2 and R.sup.3 are hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl or optionally substituted benzoyl, phenylacetyl or phenylpropionyl;R.sup.4 is hydrogen, optionally substituted C.sub.1 -C.sub.6 -alkyl, cyclohexyl, C.sub.1 -C.sub.5 alkanoyl, optionally substituted phenyl or benzyl, or an optionally substituted heteroaryl group selected from imidazolyl, pyrazolyl, pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, triazinyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, thienyl and furanyl; andR.sup.5 is hydrogen or an acyl group selected from optionally substituted C.sub.1 -C.sub.

Abstract: C-23-Modified derivatives of demycinosyltylosin (DMT) of the formula: ##STR1## wherein R is iodo, bromo, chloro, fluoro, --S--R.sup.4, azido, --NHR.sup.5, pyridinium or --OSO.sub.2 CF.sub.3 ;R.sup.1 is hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl or optionally substituted benzoyl, phenylacetyl, phenylpropionyl, phenoxyacetyl or phenylthioacetyl;R.sup.2 is hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl or optionally substituted benzoyl, phenylacetyl or phenylpropionyl;R.sup.3 is hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl or optionally substituted benzoyl, phenylacetyl or phenoxyacetyl;R.sup.4 is hydrogen, optionally substituted C.sub.1 -C.sub.6 -alkyl, cyclohexyl, C.sub.1 -C.sub.

Abstract: C-20-Modified derivatives of the macrolide antibiotics tylosin, desmycosin, macrocin, lactenocin, 2"'-O-demethylmacrocin and 2"-O-demethyllactenocin inhibit pathogenic bacteria, especially gram-positive bacteria, Pasteurella species, and Mycoplasma species and pharmaceutical compositions thereof.

Abstract: A new microorganism, Streptomyces fradiae NRRL 12201, which produces mycarosyltylactone (5-O-mycarosyl-20-dihydro-20,23-dideoxytylonolide) and a process for preparing tylactone (20-dihydro-20,23-dideoxytylonolide) and mycarosyltylactone by submerged aerobic fermentation of this microorganism, or a mycarosyltylactone-producing mutant or recombinant thereof, are provided.

Abstract: 20-Amino derivatives of tylosin and desmycosin are active against bacteria and Mycoplasma.

Abstract: 4"- and 3-Ester derivatives of 23-demycinosyltylosin (DMT) and 23-de(mycinosyloxy)tylosin (DMOT) of the formula: ##STR1## wherein R is hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl or optionally substituted benzoyl, phenylacetyl or phenoxyacetyl; R.sup.1 is hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl or optionally substituted benzoyl, phenylacetyl, or phenylpropionyl; R.sup.2 is hydrogen, optionally substituted C.sub.1 -C.sub.5 -alkanoyl, or optionally substituted benzoyl, phenylacetyl, phenylpropionyl, phenoxyacetyl or phenylthioacetyl; R.sup.3 is hydrogen or R.sup.4 O--; and R.sup.4 is hydrogen or a specified acyl group provided that one of R or R.sup.2 must be other than hydrogen and that, when R.sup.1 is hydrogen, R.sup.3 is hydrogen or --OH and R.sup.2 is acetyl, R cannot be hydrogen, acetyl, n-butyryl or isovaleryl and, when R and R.sup.1 are hydrogen and R.sup.3 is hydrogen or --OH, R.sup.

Abstract: Zinc salts are used to effect the regio-selective acylation and alkylation of the 1-amino group of 4-O-substituted-2-deoxystreptamine-containing aminoglycosides. The 1-N-substituted derivatives of apramycin, 3'-hydroxyapramycin, certain .alpha. or .beta.-(lower alkyl)aprosaminides and certain .alpha. or .beta.-(substituted lower alkyl)-aprosaminides are new. The 1-N-substituted-4-O-substituted-2-deoxystreptamine aminoglycosides produced by the process of this invention are antibacterial agents.