RESUMEN
In the screening of terrestrial Streptomycetes for bioactive components, a new antibiotic designated as diazaquinomycin C (2b) was isolated. The new antibiotic was found to be a homologue of diazaquinomycin A (2a) by spectroscopic methods and by comparison of the NMR data with those of 2a. The same strain additionally produced the akashins 1a-1c. The configuration of the N-O acetale bond in these rare glycosylated dichloroindigo derivatives was confirmed to be beta.
Asunto(s)
Antibacterianos/aislamiento & purificación , Compuestos Aza/aislamiento & purificación , Quinonas/aislamiento & purificación , Streptomyces/metabolismo , Antibacterianos/química , Compuestos Aza/química , Quinonas/química , Quinonas/farmacologíaRESUMEN
New anthracycline antibiotics 3'-O-demethyl mutactimycin (3) and 4-O,3'-O-didemethyl mutactimycin (4) were isolated from two actinomycetes strains, Nocardia transvalensis and Streptomyces sp. GW 60/1571. The chemical structures were elucidated by mass spectrometry and NMR spectroscopy. Antibiotic 3 displayed moderate antimicrobial activity against Gram-positive bacteria and cytotoxicity against P388, L1210 and HeLa tumor cells (IC50; 9.6, >25 and 20 microg/ml, respectively).