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New non-steroidal estrogen-receptor antagonists, R1128 A, B, C and D, were isolated from the cultured broth of Streptomyces sp. No. 1128 by solvent extraction, silica gel chromatography, reverse phase chromatography and preparative HPLC. These compounds inhibited estrogen binding to its receptor. The IC50 values of R1128 A, B, C and D for partially purified rat uterine cytosol receptor were 1.1 x 10(-7) M, 1.2 x 10(-7) M, 2.6 x 10(-7) M and 2.7 x 10(-7) M, respectively.

Production of biphenomycin A by Streptomyces griseorubiginosus 43708 was stimulated by a mixed culture with a partner strain, Pseudomonas maltophilia 1928. This stimulatory effect on biphenomycin A accumulation by the mixed culture was caused by the enzyme activity which strain 1928 possessed. It is suggested that in a mixed culture strain 43708 produces a precursor of biphenomycin A in culture broth and that strain 1928 converts the precursor to biphenomycin A.

WS009 A and B novel endothelin receptor antagonists, have been isolated from the fermentation broth of Streptomyces sp. No. 89009. These antagonists were purified from the culture filtrate followed by Diaion SP-207, DEAE Toyopearl column chromatography and HPLC. WS009 A and B showed selective activity in an endothelin receptor binding assay with IC50 of 5.8 x 10(-6) M and 6.7 x 10(-7) M, respectively. On the basis of spectroscopic and chemical evidence, the structures of WS009 A and B have been established as 1 and 3, and are highly hydroxylated benz[a]anthraquinone chromophores.

WS-7338 A, B, C and D, novel endothelin receptor antagonists, have been isolated from fermentation broth of Streptomyces sp. No. 7338. These antagonists were purified from the culture mycelium by extraction with acetone, followed by carbon column chromatography and HPLC. Among them, WS-7338 B showed good activity in an endothelin receptor binding assay with an IC50 of 2.7 x 10(-7) M.

FR112123 is a new oligopeptide antibiotic produced by Streptomyces viridochromogenes No. 7587. The structure of FR112123 is elucidated as N-(N6-(N2-glycyl-L-glutaminyl)-D-lysyl)-D-alanine (1) by spectroscopic and chemical evidence. It resembles a partial structure of peptidoglycan in bacteria. The compound has a superior activity against an Escherichia coli mutant sensitive to inhibitors of cell wall synthesis, although it has a weak activity against the parent strain. These suggest that FR112123 might act on the biosynthesis of bacterial cell wall.

WS1358A1 (FR104007) and B1 (FR104008), new potent inhibitors of renal dehydropeptidase, were isolated from the culture broth of strain No. 1358 which was identified as Streptomyces parvulus subsp. In vitro inhibitory activities (IC50 value) of WS1358A1 and B1 against porcine renal DHP were 3 and 600 nM, respectively.

FR109615, a new antibiotic active against Candida, was isolated from Streptomyces setonii No. 7562. Based on the spectroscopic data, the structure of FR109615 was elucidated as cis-2-aminocyclopentane-1-carboxylic acid (1). The compound showed the excellent in vivo efficacy in a generalized infection test of mice.

A new antitumor antibiotic, FR900840, was isolated from a culture broth of Streptomyces strain No. 8727 as a pale yellowish prism and the molecular formula was determined to be C7H11N3O5. The antibiotic exhibited prominent antitumor effects on human tumor cell lines both in vitro and in vivo.

Biphenomycin A, C23H28N4O8, and biphenomycin B, C23H28N4O7, were isolated from the cultured broth of Streptomyces griseorubiginosus No. 43708. The antibiotics are active in vitro and in vivo against bacteria, and are especially potent against Gram-positive bacteria. The acute toxicity of biphenomycin A is very low in mice.

Lavendomycin, a new basic peptide antibiotic containing novel amino acids, has been isolated from the culture broth of a streptomyces designated as Streptomyces lavendulae subsp. brasilicus. The antibiotic obtained as colorless crystals (C29H50N10O8, MW 666) is active against Gram-positive bacteria in vitro and in vivo, however, inactive against Gram-negative bacteria and fungi. An acute toxicity of the antibiotic in mice was LD50 greater than 2 g/kg by subcutaneous injection.