New Cytotoxic Agents, BE-54238A and B, Produced by a Streptomycete.

New Cytotoxic Agents, BE-54238A and B, Produced by a Streptomycete. A New Antitumor Antibiotic, BE-19412A, Produced by a Streptomycete. BE-32030 A, B, C, D and E, New Antitumor Substances Produced by Nocardia sp. A32030. A new antitumor substance, BE-18591, produced by a streptomycete. I. Fermentation, isolation, physico-chemical and biological properties. A new antitumor substance, BE-13793C, produced by a streptomycete. Taxonomy, fermentation, isolation, structure determination and biological activity. Two New Analogues of the Cytotoxic Substance BE-52211 from <i>Streptomyces </i>sp. Two New Analogues of the Cytotoxic Substance BE-52211 from <i>Streptomyces </i>sp. A new topoisomerase-II inhibitor, BE-10988, produced by a streptomycete. I. Taxonomy, fermentation, isolation and characterization. A new topoisomerase-II inhibitor, BE-10988, produced by a streptomycete. I. Taxonomy, fermentation, isolation and characterization. A new topoisomerase II inhibitor, BE-22179, produced by a streptomycete. I. Producing strain, fermentation, isolation and biological activity.