Isolation of azalomycins F3, F4 and Fg from azalomycin F-complex crystals was successfully conducted. F3 was less soluble in methanol than other components and was isolated by fractional crystallization of F-complex from 80~ 100% methanol in water. F4 and F5 were separated by P-cellulose column chromatography, from which F5 and F4 were eluted with 60 % aqueous methanol and 0.01M ammonium acetate in 60 % aqueous methanol, respectively. Determination of physico-chemical as well as biological properties pointed to a very close resemblance of the structures of these components.