Abstract: The present invention relates to a method for selectively enhancing the production of factors A.sub.2 and/or A.sub.3 of antibiotic A/16686 either to isolate these single components or to enrich the complex in one or both the above components, which comprises adding an appropriate precursor of the desired antibiotic factor to an A/16686 producing culture during fermentation.

Abstract: The object of this invention are de-mannosylated teicoplanin derivatives which can be obtained in good yield by microbiological transformation with cultures of Nocardia orientalis NRRL 2450 or Streptomyces candidus NRRL 3218.

Abstract: The present invention relates to new teicoplanin-like antibiotics differing from the parent compound in the length of the acyl group.The compounds of the invention are obtained according to a microbiological process and possess an antimicrobiol activity mainly against gram positive bacteria.

Abstract: The oject of this invention are de-mannosylated teicoplanin derivatives which can be obtained in good yield by microbiological transformation with cultures of Nocardia orientalis NRRL 2450 or Streptomyces candiodus NRRL 3218.

Abstract: The object of this invention is to provide a method for selectively increasing the ratio of the single T-A2 major components in the T-A2 complex. More particularly, the object of this invention is a process for obtaining teicoplanin A.sub.2 selectively enriched in any of its major components, T-A2-1, T-A2-2, T-A2-3, T-A2-4 and T-A2-5 which consists in adding to the culture medium of Actinoplanes teichomyceticus nov. sp. ATCC 31121 or a mutant thereof which produces T-A2 complex through the same metabolic pathway, a selectively effective amount of an appropriate precursor.

Abstract: The antibiotic gardimycin and process for producing said antibiotic by fermentation of strains belonging to the genus Actinoplanes.

Abstract: A biologically pure culture of Streptomyces mediterranei mutant strain 18, ATCC.

Abstract: Novel rifamycin compounds, designated P, Q, R and U, produced by the fermentation of mutant strains of Streptomyces mediterranei.

Abstract: This invention is directed to rifamycin compounds which are produced by fermentation of Nocardia mediterranea ATCC 31064, ATCC 31065 or ATCC 31066 in an aqueous nutrient medium under aerobic conditions. These rifamycins are referred to as rifamycin P, rifamycin Q, rifamycin R and rifamycin U.

Abstract: The compound 5-[(1-hydroxy-1-methyl)ethyl]-1-methyl-2-nitroimidazole is valuable in combatting Trichomonas vaginalis infections in mammals.

Abstract: The antibiotic gardimycin and process for producing said antibiotic by fermentation of strains belonging to the genus Actinoplanes.

Abstract: Hydrazones of 3-formylrifamycin SV of the general formula ##STR1## wherein R.sub.1 is selected from the group hydrogen; alkyl; phenyl; and benzyl; R.sub.2 is selected from the group alkyl; alkenyl; phenyl; and substituted phenyl; with the proviso that when R.sub.1 is hydrogen or alkyl having 1 to 4 carbons, R.sub.2 may not be phenyl; and the 16, 17; 18, 19; 28, 29-hexahydro and 27-demethoxy-27-hydroxy derivatives thereof.

Abstract: 2-Nitroimidazole derivatives of the general formula ##SPC1##Wherein R is a lower alkyl group and Y is a member of the group consisting of --CH.sub.2 OH, --CHO, CH.sub.3 CO--, vinyl, formylvinyl, styryl, substituted iminomethyl, 2-benzimidazolyl and 5-amino-1,3,4-thiadiazol-2-yl. The term "lower alkyl" designates aliphatic groups of from 1 to 4 carbon atoms; the term "substituted iminomethyl" designates nitrogen-containing functional derivatives of the aldehydic group. The compounds have antimicrobial activity.

Abstract: 2-Nitroimidazole derivatives of the general formula ##SPC1##Wherein R is a lower alkyl group and Y is a member of the group consisting of --CH.sub.2 OH, --CHO, CH.sub.3 CO--, vinyl, formylvinyl, styryl, substituted iminomethyl, 2-benzimidazolyl and 5-amino-1,3,4-thiadiazol-2-yl. The term "lower alkyl" designates aliphatic groups of from 1 to 4 carbon atoms; the term "substituted iminomethyl" designates nitrogen-containing functional derivatives of the aldehydic group. The compounds have antimicrobial activity.

Abstract: The present invention is concerned with new derivatives of 3-formylrifamycin SV. More particularly the invention relates to O-substituted oximes of 3-formylrifamycin SV of formula I. ##SPC1##wherein R is selected from the group consisting of alkyl of at least 2 carbon atoms, alkenyl, alkynyl, cycloalkyl, alkoxyalkyl, cycloalkoxyalkyl, hydroxyalkyl, carboxyalkyl, carboalkoxyalkyl, carbamylalkyl, cyanoalkyl, nitroalkyl, aryloxyalkyl, aralkoxyalkyl, heterocycloxyalkyl, aminoalkyl, mono- and di-lower alkylaminoalkyl, substituted benzyl, mono- or poly-aryl substituted C.sub.2 -C.sub.8 alkyl and lower alkyl substituted with mono- or polynuclear heterocyclic rings containing at least one 1 to 3 heteroatom selected from oxygen, nitrogen and sulfur, with the exclusion of morpholine; R.sub.1 is H or CH.sub.3 CO; and the derivatives of the same oximes hydrogenated in at least one of the positions 16, 17; 18, 19; and 28, 29. These compounds have antimicrobial activity.