Characterization of Manno-oligosaccharides Containing α(1→2)- and α-(1→6)-Linkages Obtained from Saccharomyces cerevisiae Mannan by Controlled Acid Hydrolysist

Abstract

Saccharomyces cerevisiae mannan was hydrolyzed with 0.2 N sulfuric acid at 100°C for 12 hr. Seven manno-oligosaccharides were obtained from the hydrolysates by carbon column chromatography followed by gel filtration and characterized by 1H-NMR. Two of them contained α-(1→2)- and α-(1→6)-mixed linkages. This result differed from those obtained by PEAT et al. but agreed with those obtained recently by us (0.33 N sulfuric acid was used for hydrolysis in each experiment). It has been considered that acid hydrolysis of the yeast mannan may cause preferential cleavage of α-(1→2)-linked side chains, consequently yield a homologous series of α-(1→6)-linked manno -oligosaccharide based on the results that (1→6)-glycosidic linkage is much more stable toward acid hydrolysis than the (1→2)-glycosidic one, but our results disproved this idea and suggested that acid hydrolysis of highly branched yeast mannan is complex.