Synthesis of Some Disaccharides Containing an L-Rhamnopyranosyl or L-Mannopyranosyl Residue, and the Substrate-specificity of α-L-Rhamnosidase from Aspergillus niger

Abstract

In order to investigate the substrate-specificity of α-L-rhamnosidase from Aspergillus niger, the following disaccharides were synthesized: 2-O-α-L-rhamnopyranosyl-α-D-fucopyranose (1), methyl 4-O-α-L-rhamnopyranosyl-β-L-arabinopyranoside (2), methyl 2-O-α-L-rhamnopyranosyl-α-L-rhamnopyranoside (3) and 6-O-α-L-mannopyranosyl-D-glucopyranose (4). The action of α-L-rhamnosidase on compounds 1-4 and another fifteen disaccharides containing α- or β-L-rhamnopyranosidic bonds or an a-L-mannopyranosidic bond was examined. As the result, all the disaccharides having an α-L-rhamnopyranosidic linkage were hydrolyzed well, while the ones having β-L-rhamnopyranosidic or α-L-mannopyranosidic linkage could not be hydrolyzed at all. Accordingly, this enzyme might be used for the determination of anomeric configurations of the L-rhamnopyranosidic bond, although further studies on the specificity of the enzyme are required. Copyright © 1985, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.