SF-1771, a new antibiotic related to bleomycin

A new antibiotic, substance SF-1771, has been isolated for the fermentation broth of Streptomyces toyocaensis SF-1771. The antibiotic is highly active against Gram-positive and -negative bacteria and effective against sarcoma 180 cells of ascites type in mice. It belonged to the phleomycin-bleomycin group antibiotics, but has been differentiated from the known antibiotics by the physiochemical properties, chromatographic behaviors and amino acid analysis.