title: Relationship between structure and activity of an anti-complementary arabinogalactan from the roots of Angelica acutiloba Kitagawa.
abstract: An anti-complementary arabinogalactan (AGIIb-1), isolated from the roots of Angelica acutiloba Kitagawa, comprised one neutral (N-I) and two acidic arabinogalactan (A-I and A-II) units and one neutral arabinan unit (N-II). N-I showed the most potent anti-complementary activity. AGIIb-1, A-I, and A-II had similar moderate activities, but N-II had weak activity. The product (AF-AGIIb-1) of digestion of AGIIb-1 with exo-alpha-L-arabinofuranosidase had markedly increased anti-complementary activity, as did that (AF-N-I) of N-I. Degradation of the rhamnogalacturonan core in AGIIb-1 slightly decreased the anti-complementary activity, whereas the high-molecular-weight neutral arabinogalactan and galacto-oligosaccharide side-chains in A-I and A-II showed potent activities. When AF-AGIIb-1 was digested with endo-arabinanase, the activity decreased slightly. Partial elimination of the (1--6)-beta-D-galactosyl side-chains from AF-N-I by digestion with exo-beta-D-galactosidase did not affect the activity. AGIIb-1 reacted weakly with the beta-D-glucosyl-Yariv antigen, but AF-AGIIb-1 and AF-N-1 had increased reactivity with the antigen. The anti-complementary activity of AGIIb-1 was expressed mainly through the classical pathway, whereas AF-AGIIb-1 and AF-N-I had markedly increased activity through the alterative pathway.
authors.affiliation: Oriental Medicine Research Center of the Kitasato Institute, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kiyohara
authors.forename: J C
authors.initials: JC
authors.lastname: Cyong
authors.forename: H
authors.initials: H
authors.lastname: Yamada
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology; D001391:Azo Compounds / Q000276:immunology; D002241:Carbohydrates / Q000494:pharmacology; D015941:Complement Hemolytic Activity Assay; D003169:Complement Inactivator Proteins; D005685:Galactans; D005779:Immunodiffusion; D066298:In Vitro Techniques; D010636:Phenols / Q000276:immunology; D010944:Plants / Q000032:analysis*; D011134:Polysaccharides / Q000494:pharmacology; D012756:Sheep; D013329:Structure-Activity Relationship
chemical_list: D000941:Antigens; D001391:Azo Compounds; D002241:Carbohydrates; D003169:Complement Inactivator Proteins; D005685:Galactans; D010636:Phenols; D011134:Polysaccharides; C062640:anti-complementary arabinogalactan