[Spergualin a novel antitumor antibiotic produced by Bacillus laterosporus]

Spergualin, named after the spermidine and guanidine moieties in its structure, was isolated from culture broth Bacillus laterosporus of based on its greater growth-inhibitory activity against chick embryo fibroblasts (CEF) transformed by Rous sarcoma virus compared with that against normal CEF. The structure of spergualin was determined as (-)-(15S)-1-amino-19-guanidino-11, 15-dihydroxy-4, 9, 12-triazanonadecane-10, 13-dione. Spergualin is water-soluble, basic and a white powder. It shows cytotoxicity in vitro against mouse leukemias L1210 and L5178Y. It significantly prolongs the life span of mice transplanted with either of the above leukemic cells. It induces a strong and specific immunological effect on L1210 which has been maintained in our laboratory; L1210-transplanted CDF1 mice, once cured by spergualin, reject a second challenge of the leukemic cells. Spergualin hibits in growth in vitro of both Gram (+) and (-) bacteria at concentrations ranging from 6.25 to 100 micrograms/ml.