Studies on auromomycin.
A new antitumor antibiotic, named auromomycin, was isolated from the culture broth of Streptomyces macromomyceticus, a macromomycin-producing strain. The antibiotic was recovered from the culture filtrate by salting out with ammonium sulfate and further purified by successive application of ion-exchange chromatography on Amberlite IRA-93 (Cl form) and DEAE-Sephadex (OH form), Gel filtration on Sephadex G-50 and hydrophobic chromatography on Octyl-Sepharose CL-4B. The antibiotic is an acidic polypeptide with a molecular weitht of 12,500 and an isoelectric point of pH 5.4 and consists of 16 different amino acids. It has characteristic absorption maxima at 273 nm and 357 nm in the ultraviolet spectrum and two minima at 280 nm and 350 nm in the optical rotatory dispersion spectrum. Auromomycin exhibits antibacterial activity not only against Gram-positive bacteria, but also Gram-negative bacteria. Antitumor activities of auromomycin were revealed against EHRLICH ascites carcinoma, ascites sarcoma 180, L1210 leukemia and LEWIS lung carcinoma. Auromomycin was found to be converted into macromomycin by adsorption chromatography on Amberlite XAD.