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Four novel nitrogen-free glycosides of platenolides I and II were isolated as secondary shunt metabolites of the turimycin biosynthesis from the culture broth of an industrial strain of Streptomyces hygroscopicus IMET JA 6599. By spectral (MS, 1H and 13C NMR) studies the structures of the glycosides have been settled as 5-O-(4',6'-dideoxy-3'-C-acetyl-beta-D-hexopyranosyl)-platenolide I (DDAH-Pl-I), 5-O-(4',6'-dideoxy-3'-C-acetyl-beta-D-hexopyranosyl)-platenolide II (DDAH-Pl-II), 5-O-(4',6'-dideoxy-3'-C-acetyl-beta-D-hexopyranosyl)-14-hydroxyl-platenolide II (DDAH-OH-Pl-II) and 5-O-(6'-deoxy-3'-C-acetyl-beta-D-hexopyranosyl)-platenolide II (DAH-Pl-II). A fifth glycoside, 5-O-(6'-deoxy-3'-C-acetyl-beta-D-hexopyranosyl)-platenolide I (DAH-Pl-I) was identified through its MS data.

Three novel glycosides of platenolides I and II containing either mycarose (2,6-dideoxy-3-C-methyl-L-ribohexopyranose) or 3-demethyl-mycarose (2,6-dideoxy-L-ribohexopyranose) were isolated as the shunt products of turimycin biosynthesis by an industrial strain of Streptomyces hygroscopicus IMET JA 6599. By means of MS, 13C and 1H NMR spectroscopic studies, their structures were assigned as 5-O-(alpha-mycarosyl)-platenolide I (MYC-Pl-I), 5-O-(alpha-mycarosyl)-platenolide II (MYC-Pl-II) and 5-O-(3'-demethyl-beta-mycarosyl)-platenolide II (DM-MYC-Pl-II). The occurrence of 3-demethyl-mycaroside amongst the shunt metabolites is discussed in terms of its biosynthesis.