[New heptaene antibiotic, flavomycin, formed by Act. flavus var. geptinicus var. nov]

An actinomycetous culture LIA-0734 was isolated from a soil sample. By its morphologo-cultural properties it was close to Act. flavus and differed from the latter in the sporophores, colour of the substrate mycelium on synthetic media amd markedly pronounced antagonism with respect to yeasts and yeast-like fungi. The culture was classified as Act. flavus var. geptinicus var. nov. The actinomycete produced new aromatic heptaens: flavomycins A and B. Their physico-chemical and biological characteristics and singularity are presented.