title: Further structural studies of anti-complementary acidic heteroglycans from the leaves of Panax ginseng C.A. Meyer.
abstract: The three potent anti-complementary polysaccharides, GL-PI, GL-PII, and GL-PIV, isolated from the leaves of Panax ginseng C. A. Meyer, were subjected to base-catalysed beta-elimination in the presence of sodium borodeuteride or enzymic digestion with endo-alpha-D-(1----4)-polygalacturonase. beta-Eliminative degradation of GL-PI and GL-PII each gave neutral (IN and IIN) and acidic (IA and IIA) fractions. Each fraction N consisted of Ara, Rha, Gal, and Glc, whereas each fraction A comprised a large proportion of GalA in addition to Rha, Gal, Glc, and GLcA. Methylation analysis and g.l.c.-m.s. showed that each fraction IN and IIN contained Rha-(1----2)-Rha-ol-1-d, Rha-(1----4)-Rha-ol-1-d, Ara-(1----4)-Rha-ol-1-d, Gal-(1----4)-Rha-ol-1-d, Gal-(1----6)-Gal-ol-1-d, and GlcA-(1----4)-Rha-ol-1-d, and that IA and IIA contained Rha----Rha-ol-1-d, HexA----Rha-ol-1-d, and HexA----Rha----Rha-ol-1-d. Methylation analysis indicated that IN and IIN also contained high-molecular-weight 6-linked galactan and 4-linked glucan, and that IA and IIA consisted mainly of 2-linked Rha, 4-linked GalA, and terminal and 6-linked Gal. IIA contained more 2-linked Rha than IA. Endo-alpha-D-(1----4)-polygalacturonase-mediated digestion of GL-PIV produced a high-molecular-weight fraction (PG-1) which was rich in neutral sugars, fragments of intermediate size (PG-2), and oligosaccharides (PG-3). PG-1 contained a rhamnogalacturonan core, galactan (which mainly comprised terminal, 6-linked, and 4,6-disubstituted Gal), and 4-linked glucans. PG-2 contained (1----4)-linked alpha-galacturonan partially branched at position 2 or 3 and a rhamnogalacturonan core in addition to small proportions of Gal and Glc. PG-3 contained large proportions of oligogalacturonides.
authors.affiliation: Oriental Medicine Research Center of the Kitasato Institute, Tokyo, Japan.
authors.forename: Q P
authors.initials: QP
authors.lastname: Gao
authors.forename: H
authors.initials: H
authors.lastname: Kiyohara
authors.forename: H
authors.initials: H
authors.lastname: Yamada
mesh_terms: D002240:Carbohydrate Sequence; D003169:Complement Inactivator Proteins; D008401:Gas Chromatography-Mass Spectrometry; D008745:Methylation; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D005894:Panax / Q000032:analysis*; D010946:Plants, Medicinal; D011096:Polygalacturonase; D011134:Polysaccharides; D013402:Sugar Alcohols
chemical_list: D003169:Complement Inactivator Proteins; D011134:Polysaccharides; D013402:Sugar Alcohols; D011096:Polygalacturonase