REQUINOMYCIN, AN INHIBITOR OF R-FACTOR TRANSFER: ISOLATION, CHARACTERIZATION AND PROPERTIES

Abstract

A new member of the anthracycline group of antibiotics named requinomycin has been isolated from a strain of Streptomyces filamentosus which had been screened for anti-phage activity. The antibiotic was obtained as yellow crystals, whose molecular formula was assigned to C₄₀H₅₄N₂O₁₆. It inhibits the reproduction of phage f 2 in E. coli S-26, the transfer of R-factors between E. coli strains, the growth of Gram-positive bacteria and the growth in vitro of YOSHIDA rat sarcoma cells. Requinomycin resembles aklavin but they are apparently different in antibiotic activity against E. coli B and stability to acid hydrolysis.