A new anthracycline antibiotic, IT-62-B, converts the morphology of ras-transformed cells back to normal: taxonomy, fermentation, isolation, structure elucidation and biological characterization.

Abstract

A new antibiotic, IT-62-B was isolated from the culture broth of Streptomyces sp. IT-62 by extraction with acetone and then with ethyl acetate, followed by conventional column chromatography using silica gel, Sephadex LH-20 and silica ODS. Its structure (C39H47NO15, MW 769) was determined by 1H, 13C NMR, MS, IR and UV spectrometric techniques to be a new member of the baumycin-group anthracyclines. It showed moderate activity against Gram-positive bacteria and had antitumor activity against various tumor cell lines. Further, antibiotic IT-62-B converted the morphology of ras-transformed NIH3T3 cells and T-cells back to normal at concentrations inhibiting cell growth by 30% or more.