NEW ANTITUMOR SUBSTANCES, BE-12406A AND BE-12406B, PRODUCED BY A STREPTOMYCETE .1. TAXONOMY, FERMENTATION, ISOLATION, PHYSICOCHEMICAL AND BIOLOGICAL PROPERTIES

Next antitumor substances, designated BE-12406A and BE-12406B, were isolated from the culture broth of a streptomycete, strain BA12406. The active principles were extracted from mycelium by methanol and successively purified by silica gel column chromatography and preparative TLC. BE-12406A and BE-12406B inhibited the growth of vincristine-resistant or doxorubicin-resistant P388 murine leukemia cell lines as well as their parent sensitive cell line. In in vivo experiments, BE-12406A inhibited the growth of S-180 murine ascites tumor.