DIOXAMYCIN, A NEW BENZ[A]ANTHRAQUINONE ANTIBIOTIC

A new antibiotic, dioxamycin (1) was isolated from the culture broth of the strain MH406-SF1, which was closely related to Streptomyces xantholiticus. This antibiotic was purified by countercurrent chromatography, column chromatography and preparative HPLC. The molecular formula of 1 was determined to be C38H40O15 by HRFAB-MS. The structure was determined by spectral analysis of 2D NMR; H-1-H-1 COSY, C-13-H-1 COSY, long range C-13-H-1 COSY (HMBC) and NOESY. The antibiotic is active in vitro against Gram-positive bacteria and some tumor cells. Dioxamycin is a benz[a]anthraquinone antibiotic related to capoamycin.