Abstract: A novel antiviral antibiotic AM-2722 is described represented by the molecular formula C.sub.19 H.sub.26 NO.sub.3 Cl, and having the following physicochemical properties:(1) specific rotary power: [.alpha.].sub.D.sup.20 -0.5 (C-1, chloroform);(2) the UV spectrum shown in FIG. 1; and(3) the IR spectrum shown in FIG. 2.Also described is a process for producing the antiviral antibiotic AM-2722, wherein a microorganism of Streptomyces which has the ability to produce the antibiotic AM-2722 is cultured aerobically in a nutrient medium and the antibiotic AM-2722 accumulated in the medium and the microorganism cells is recovered.

Abstract: There is disclosed a new antibiotic agent, A73A, produced by Streptomyces viridifaciens MA-4864 (ATCC 31495) under suitable conditions. Said antibiotic shows antibacterial and growth-permittant activity.

Abstract: There is disclosed a new antibiotic agent, A40A, produced by Streptomyces lavedulae MA-4758 (ATCC 31312) under suitable conditions. Said antibiotic shows antibacterial and growth-permittant activity.

Abstract: There is disclosed a new antibiotic agent, A73A, produced by Streptomyces viridifaciens MA-4864 (ATCC 31495) under suitable conditions. Said antibiotic shows antibacterial and growth-permittant activity.

Abstract: The present invention relates to a new composition designated as AM-1042 or asukamycin. AM-1042 has an antibiotic activity upon Gram-positive bacteria and Eimeria, and its acute toxicity (LD.sub.50 ' ip.) in mice was 48.5 mg./kg. AM-1042 has an excellent therapeutical effect on various infectious diseases caused by a parasite of Gram-positive bacteria and Eimeria. AM-1042 has been confirmed to be distinguishable from known antibiotics such as e.g. amicetin B, azomycin and manumycin. AM-1042 is produced by fermentation of a microorganism belonging to the genus Streptomyces and capable of producing AM-1042. A composition capable of preventing and curing coccidiosis of poultry containing AM-1042 as active ingredient.

Abstract: Trichostatin (I) is disclosed to be useful as an antiprotozoal agent for the treatment of diseases in man and animals. Also disclosed are pharmaceutical compositions comprising trichostatin for treating protozoal infections.

Abstract: A novel compound frenolicin B of the formula: ##STR1## is prepared by cultivating a microorganism belonging to genus Streptomyces, e.g. Streptomyces roseofulvus AM-3867, in a culture medium and isolating the compound formed and accumulated in the medium from the cultured product. Said frenolicin B is useful as an antibiotic.

Abstract: The present invention relates to a new antibiotic designated as OS-3256-B. OS-3256-B exhibits excellent inhibitory activities against animal tumors such as leukemia L-1210, Sarcoma-180 and Hela cells and gram-positive bacteria and is classified into the diazocompounds group. However, chromatographic analysis, Rf value and other experimental data reveal that OS-3256-B is a new compound of the type of azaamino acid derivatives. The present invention also provides a process for producing OS-3256-B by fermentation, in which OS-3256-B is produced by culturing a microorganism belonging to Streptomyces candidus var. azaticus in a culture medium conventionally used for culturing Streptomyces strain microorganisms.