Microbial reduction of the side-chain carbonyl of daunorubicin and N-acetyldaunorubicin

Abstract

Microorganisms reduced the side-chain carbonyl of daunorubicin to yield 13-dihydrodaunorubicin (daunorubicinol; daunomycinol). This microbial transformation occurred under aerobic conditions in agitated baffled shake flasks incubated at 37 degrees C. The microorganisms were first grown in a medium which supported dense growth. Daunorubicin-HCl was then added. Following a period of incubation, broths were adjusted to pH 10.0 and extracted with chloroform. Daunorubicinol was recovered and purified from the chloroform extracts by preparative TLC. Identity of the daunorubicinol was established by TLC and spectroscopy (UV-vis, IR, NMR, MS, CD and ORD). N-Acetyldaunorubicin was likewise reduced microbially to N-acetyldaunorubicinol. N-Acetyldaunorubicinol appears to be a new compound which is yet to be tested for antitumor activity.