STUDIES ON ANTIBIOTIC SF-733, A NEW ANTIBIOTIC. II: CHEMICAL STRUCTURE OF ANTIBIOTIC SF-733

A new antibiotic SF-7331) gave neamine2) and methyl D-riboside on acid methanolysis and a furanoside nature of the ribose moiety was determined by periodate oxidation of tetra-N-acetyl SF-733. The site of linkage was determined by the formation of di-N-acetyl-6-O-methyl-2-deoxystreptamine after acid hydrolysis of tetra-N-acetyl-hexa-O-methyl SF-733. The NMR spectrum of tetra-N-acetyl SF-733 was compared with those of N-acetylated neomycin group of antibiotics and it was concluded that the ribofuranosyl linkage was β. Thus, the chemical structure of antibiotic SF-733 was determined to be O-β-D-ribofuranosyl-(1→5)-O-[α-2, 6-diamino-2, 6-dideoxy-D-glucopyranosyl-(1→4)] -2-deoxystreptamine.