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.