Structural studies on hairy region of pectic polysaccharide from campion Silene vulgaris (Oberna behen)

Using enzymic digestion with pectinase, controlled Smith degradation and NMR-spectroscopy, some structural features of the hairy region of pectic polysaccharide termed silenan SV from the aerial part of campion Silene vulgaris (Moench) Garke (Oberna behen (L.) Ikonn) were elucidated. Silenan was subjected to enzymic digestion with pectinase to furnish the polysaccharide fraction (SVP). The contained residues Of D-galacturonic acid (43%), arabinose, galactose and rhamnose as main constituents. The backbone of the hairy region of silenan was found to consist of alpha-1,4-galactopyranosyl uronic acid and 2-O-glycosylated rhamnopyranose residues. The side chains contained linear regions of residues of alpha-1,5-linked arabinofuranose and beta-1,3-, beta-1,4-linked galactopyranose. Silenan SV and its fragment SVP were subjected to Smith degradation to give fractions SVS and SVPS. These contain the residues of terminal and 2-substituted alpha-arabinofuranose as well as residues of terminal, 3-, and 2,3-substituted beta-galactopyranose. In addition, NMR-spectral data confirmed that the residues of alpha-rhamnopyranose 2-O-glycosylated with the residues of alpha-1,4-galactopyranosyl uronic acid of the backbone occurred in the core of SVPS and, therefore, in the backbone of silenan SV. On the basis of data obtained, the hairy regions of silenan were suggested to contain mainly the linear chains of beta-1,3-, beta-1,4-galactopyranan and alpha-1,5-arabinofuranan. The chains of alpha-1,5-linked arabinofuranose, beta-1,3- and beta-1,4-linked galactopyranose were shown to be involved in the side chains of the hairy region having branching points at 2,3-substituted beta-galactopyranose residues. (C) 2002 Elsevier Science Ltd. All rights reserved.