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Biomedical subjects

H Seto

Publications and source records attributed to H Seto.

At least 361 records · Page 20Linked to original sources
PubMed1983

Studies on biosynthesis of pentalenolactone. V isolation of deoxypentalenylglucuron.

Deoxypentalenylglucuron was isolated from the culture broths of three different strains, such as Streptomyces omiyaensis, S. albofaciens and S. viridifaciens. The structure of deoxypentalenylglucuron has been determined by 1H and 13C NMR, mass spectroscopy and by chemical correlation to be an oxidation product of pentalenene 1. Deoxypentalenylglucuron (1) has some antitumor activity against Sarcoma 180 in mice.

Animals↗
PubMed1983

Leptomycins A and B, new antifungal antibiotics. II. Structure elucidation.

The structures of new antifungal antibiotics, leptomycins A and B produced by Streptomyces sp. ATS1287 were determined as described below (Fig. 1) on the basis of their spectral and chemical character. Leptomycins have unique structures which belong to the unsaturated, branched-chain fatty acids with delta-lactone rings at the end.

Antifungal Agents↗
PubMed1983

Potentiation of mitomycin C, 6-mercaptopurine, bleomycin, cis-diamminedichloroplatinum and 5-fluorouracil by mycotrienins and mycotrienols.

Mycotrienins I and II and mycotrienols I and II are ansamycin antibiotics containing a triene structure, isolated from Streptomyces rishiriensis. An amphotericin B-resistant clone (AMBR-1) derived from cultured Chinese hamster V79 cells was cross-resistant to mycotrienins I and II, but not to mycotrienol I or II. These four ansamycin antibiotics were found to potentiate significantly the action of some anti-cancer agents including 5-fluorouracil, cis-diamminedichloroplatinum, bleomycin, mitomycin C and 6-mercaptopurine against cultured V79 cells. The action of adriamycin was not potentiated. These four ansamycin antibiotics showed a synergism spectrum similar to that of smaller polyene antibiotics.

Animals↗
PubMed1982

Ferensimycins A and B. Two polyether antibiotics. Taxonomy, fermentation, isolation, characterization and structural studies.

Ferensimycin A* (I), C34H59O10Na, mp 133 approximately 135 degrees C, and ferensimycin B** (II), C35H61O10Na, mp 143 approximately 145 degrees C, were isolated as their sodium salts from the fermentation broth of Streptomyces sp. No. 5057, a strain similar to Streptomyces myxogenes Shomura et al. The physicochemical data of I and II showed that they are both closely related congeners of lysocellin (III). Ferensimycins A and B exhibit activity against Gram-positive bacteria and are effective in the treatment of coccidiosis of fowl.

Animals↗