STUDIES ON SF-1902 A₂-A₅, MINOR COMPONENTS OF SF-1902 (GLOBOMYCIN)

Abstract

Four members of globomycin, SF-1902 A₂, A₃, A_4a and A_4b were newly isolated from the culture of Streptomyces hygroscopicus SF-1902. These minor components shared four amino acids in common and the fifth was either valine or allo-isoleucine. The fatty acid moiety varied from 3-hydroxy-2-methylheptanoic acid in A₂ to 3-hydroxy-2-methylundecanoic acids in A_4b. The length of alkyl chain greatly affected the antibacterial activity, and maximum activity was shown by the homologue (A₅) possessing the longest alkyl chain.