Structural studies of plant gum from sap of the lac tree, Rhus vernicifera

✍ Scribed by Ryuichi Oshima; Ju Kumanotani

• Book ID: 102993195
• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 962 KB
• Volume: 127
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(84)85105-8

✦ Synopsis

The plant gum isolated from sap of the lac tree, Rhus vernicifera (China), was separated into two fractions having mol. wt. 84,000 and 27,700 by aqueous-phase gel-permeation chromatography. The fractions contain D-galactose (6.5 mol%), 4-O-methyl-D-glucuronic acid (24 mol%), D-ghrcuronic acid (3 mol%), L-arabinose (4 mol%), and L-rhamnose (3 mol%). Smith degradation of the carboxyl-reduced polysaccharides gives products of halved molecular weight, and these consist of a P-(l-+3)-linked galactopyranan main chain and side chains made up of galactopyranose residues. Peripheral groups, such as cw-D-Galp-, a-D-Galp-( l-+6)-B-D-Galp-, 4-O-methyl-P-D-GlcpA-, and 4-O-methyl-P-D-GlcpA-(l--+6)-/?-D-Galp-, are attached to this interior core through p-(1-+3)-or p-(1+6)-linkages.