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AM-2282, a new alkaloid has been isolated from cultures of Streptomyces sp. AM-2282 by solvent extraction and silica gel chromatography. The compound exhibits a strong absorption maximum at 292 nm and shows antimicrobial activity against fungi and yeast. The LD50 of its hydrochloride (i.p. in mice) is 6.6 mg/kg. The molecular formula of AM-2282 has been determined as C28H26N4O3. The producing strain, AM-2282 was classified as a new species and the name, Streptomyces staurosporeus AWAYA, TAKAHASHI and OMURA, nov. sp. is proposed.

New antibiotics, OS-4742 A1, A2, B1 and B2, were isolated from the culture broth of the strain OS-4742, which was designated as Streptomyces matensis subsp. vineus. These compounds have anthracycline chromophores and sugar moieties, but do not contain nitrogen. They possess antimicrobial activities against Gram-positive bacteria and antitumor activities against S-180 solid tumor on mice.

A new antibiotic, setomimycin, was isolated from the culture broth of strain AM-2947, which was identified as Streptomyces pseudovenezuelae. The compound is a weakly acidic substance, and has UV-absorption at 228, 268 and 422 nm and a molecular formula of C34H28O9 (MW 580). It is active against Gram-positive bacteria including Mycobacteria, and has antitumor activity against Sarcoma-180 solid tumor in mice.

Nanomycins are new antibiotics produced by the strain OS-3966 which was designated Streptomyces rosa var. notoensis. Nanomycins A and B were isolated from the culture filtrate by extraction with organic solvent and silica gel chromatography. The physical and chemical properties suggest that nanaomycins A and B are quinone-related compounds having the molecular formulae, C16H14O6 and C16H16O7, respectively. Nanaomycins A and B inhibit mainly mycoplasmas, fungi and Gram-positive bacteria. The acute toxicities (LD50, ip) of nanaomycins A and B in mice are 28.2 and 169 mg/kg, respectively.

9-beta-D-Arabinofuranosyladenine (ara-A) was produced by a new species of Streptomyces designated as S. herbaceus. Ara-A was found to have potent herbicidal activity against Echinochloa crus-galli, Digitaria adscendens and Chenopodium ficifolium by the treatment with ara-A before germination of these plants. However, Oryza sativa had strong resistance to ara-A.

Two metabolites have been isolated from the fermentation broth of a new species of Kitasatoa, Kitasatoa griseophaeus. These alkaloids have been identified as quinoline-2-methanol and quinoline-2-methanol acetate. The former exhibits hypoglycemic activity in the rat.

Two antibiotics of frenolicin group, antibiotic AM-3867 I and II were isolated from the fermentation broth of Streptomyces roseofulvus strain No. AM-3867, a soil isolate. The former was a new antibiotic designated as frenolicin B and its structure containing gamma-lactone was determined, while the latter was identified as deoxyfrenolicin having been chemically prepared from frenolicin.

Elasnin, a new human granulocyte elastase inhibitor, produced by the strain of KM-2753 designated as Streptomyces noboritoensis KM--2753 has been isolated from the fermentation broth by column chromatography on silica gel and neutral alumina. Elasnin is a neutral, colorless, and viscous oil (ND17 = 1.4983, [alpha]18D -0.9 degrees, lambdaEtOHmax 291 nm (epsilon, 7,760) having a molecular formula of C24H40O4 (MW 392) as shown by its elemental analysis and mass spectrum. Elasnin markedly inhibits human granulocyte elastase, but it is almost inactive against pancreatic elastase, chymotrypsin, and trypsin. At 1.3 microgram/ml (3.3 X 10(-6) M), elasnin is 50% inhibitory to human elastase, but it causes 50% inhibition of pancreatic elastase at 30.1 microgram/ml (76.8 X 10(-6) M).

A new antibiotic O-2867 inhibiting the growth of Piricularia oryzae, a plant pathogenic fungus of rice, was isolated from a Streptomyces sp. Antibiotic O-2867 is water-soluble, amphoteric and consists of 2 components, O- 2867-α and β. O-2867-α was obtained as an amorphous powder and O-2867-β as colorless needles. Both antibiotics are active against P. oryzae in vitro but are not effective in pot tests using rice plants infected with P. oryzae.