Structure of oligosaccharide side chains of an intestinal immune system modulating arabinogalactan isolated from rhizomes of Atractylodes lancea DC

摘要

An intestinal immune system modulating arabino-3,6-galactan (ALR-5IIa-l-l) has been found in rhizomes of Atractylodes lancea DC.[Planta Medica 1998,64,714-719;Carbohydr.Polyms.2001,46,147-156],however other arabino-3,6-galactans from Larix and Acacia failed to express the modulating activity.Degradation of the galactosyl side chains in Ara/-side chain-trimmed ALR-5IIa-l-l (AF-ALR-5IIa-l-l) with an endo-beta-D-(l ->6)-galactanase remarkably decreased the activity of AF-ALR-5IIa-l-l.Structural analysis indicated that the major endo-beta-D-(l->6)-galactanase-digestable side chains in ALR-5IIa-l-l are composed of beta-D-(1->6)-galactopyranosyl oligosaccharides having d.p.1-8.Because degradation of the beta-D-(l->3)-galactan backbone in AF-ALR-5IIa-l-l also significantly reduced its activity,some of these galactosyl side chains attached to beta-D-(1->3)-galactan backbone are suggested to be responsible for expression of the activity of ALR-5IIa-1-1.