STUDIES ON NEW ANTIBIOTIC LIVIDOMYCINS. IV: STRUCTURE OF LIVIDOMYCIN A

The acid hydrolysis of methyl lividotriosaminide obtained from the methanolysis of lividomycin A gave D-mannose, D-ribose and neosamine B. The sequence and the position of linkage of these three compounds were determined. 1-O-Acetyl-2, 3, 4, 6-tetra-O-methyl-α-D-mannose and l, 3-di-O-acetyl-2, 5-di-O-methyl-β-D-ribose were formed by acid hydrolysis of di-N-acetyl-deca-Omethyllividomycin A followed by acetylation and other observations. The attachment to 2-deoxystreptamine of lividotriosamine was determined by the formation of di-N-acetyl-6-O-methyl-2-deoxystreptamine. The stereochemistry of the glycosidic linkage was determined by comparison of the NMR spectra of N-acetylated derivatives of lividomycin A and paromomycin. Thus, the chemical structure of lividomycin A was concluded to be 4-O-(2-amino-2, 3-dideoxy-α-D-glucopyranosyl)- 5 -O- [3-O- {4-O-(α-D-mannopyranosyl)-2, 6-diamino-2, 6-dideoxy-α-L-idopyranosyl} -β-D-ribofuranosyl]-1, 3-diamino-1, 2, 3-trideoxy-myo-inositol or mannosyldeoxyparomomycin.