New antibiotics, carbazomycins A and B. I. Fermentation, extraction, purification and physico-chemical and biological properties.

An unidentified Streptomyces, designated as Strain H 1051-MY 10, was proved to produce viomycin and two new antibiotics. The new antibiotics were extracted from the cultured mycelia with acetone and transferred to ethyl acetate after acetone was removed in vacuo. The extracted antibiotics were separated into two components by alumina column chromatography and named carbazomycins A and B, because both antibiotics were proved to contain a carbazole nucleus. The molecular formulae of carbazomycins A and B were determined to be C16H17NO2 and C15H15NO2, respectively. Further, carbazomycin B was methylated with diazomethane to give carbazomycin A. Carbazomycins inhibited the growth of phytophathogenic fungi and further showed weak antibacterial and antiyeast activities.