title: Pectin isolated from white cabbage--structure and complement-fixing activity.
abstract: This study was done to investigate whether white cabbage contained polysaccharides with immunostimulatory activity using the complement-fixing test as an indicator. The main polysaccharide isolated was of pectin nature. Methanolysis and (13)C-NMR showed that the polymers consisted of highly esterified alpha-galactopyranoside (alpha-GalpA), significant amounts of alpha-arabinose furanoside (alpha-Araf), beta-Galp and lesser amounts of rhamnose in the pyranose form (Rhap) and xylose in the pyranose form (Xylp). Linkage analyses showed that the alpha-GalpA residues were mainly 1,4-linked with small amounts of 1,3,4-linkages. The alpha-Araf residues were mainly terminally (t)- and 1,5-linked, whereas beta-Galp was t-, 1,3-, 1,6-, and 1,3,6-linked. Positive Yariv reaction indicated polymers with arabinogalactan type 2 like structures. alpha-Rhap was mainly present as 1,2- and 1,2,4-linked residues and Xylp was t- and 1,4-linked. The molecular weight varied greatly and was from 10 to 150 kDa. Cabbage polymers had biological activity and this complement-fixing activity was greatly affected by hydrolytic removal of Araf from pectic side chains.
authors.affiliation: School of Pharmacy, Department of Pharmaceutical Chemistry-Pharmacognosy, University of Oslo, Blindern, Oslo, Norway. bjorge.westereng@matforsk.no
authors.forename: Bjørge
authors.initials: B
authors.lastname: Westereng
authors.forename: Osman
authors.initials: O
authors.lastname: Yousif
authors.forename: Terje E
authors.initials: TE
authors.lastname: Michaelsen
authors.forename: Svein Halvor
authors.initials: SH
authors.lastname: Knutsen
authors.forename: Anne Berit
authors.initials: AB
authors.lastname: Samuelsen
mesh_terms: D001089:Arabinose / Q000737:chemistry; D001937:Brassica / Q000737:chemistry*; D002236:Carbohydrate Conformation; D003165:Complement System Proteins / Q000187:drug effects*; D005690:Galactose / Q000737:chemistry; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D010368:Pectins / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D011108:Polymers / Q000737:chemistry; D012210:Rhamnose / Q000737:chemistry; D013213:Starch / Q000032:analysis
chemical_list: D011108:Polymers; D010368:Pectins; D013213:Starch; D003165:Complement System Proteins; D001089:Arabinose; D012210:Rhamnose; D005690:Galactose