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PubMed · 16398500

Structures and structure-activity relationships of three mitogenic and complement fixing pectic arabinogalactans from the malian antiulcer plants Cochlospermum tinctorium A. Rich and Vernonia kotschyana Sch. Bip. ex Walp.

Cecilie Sogn Nergard·Hiroaki Kiyohara·James C Reynolds·Jane E Thomas-Oates·Tsukasa Matsumoto·Haruki Yamada·Trushar Patel·Dirk Petersen·Terje E Michaelsen·Drissa Diallo·Berit Smestad Paulsen
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Abstract

Structures of three pectic arabinogalactans, one from Vernonia kotschyana (Vk2a) and two from Cochlospermum tinctorium (Ct50A1 and Ct50A2), and their complement fixation and induction of B cell proliferation in vitro were compared. The polysaccharide Vk2a expressed potent biological activity in both assays compared with Ct50A1 and Ct50A2. Vk2a possessed a very high molecular weight (1150 +/- 20 kDa) compared with Ct50A1 and Ct50A2 which both showed a polydisperse nature with the highest molecular weight polymers in each fraction estimated at approximately 105 kDa (Ct1a) and 640 +/- 100 kDa (Ct2a), respectively. The HMW polymers showed complement fixation in the same range as the native fractions. The arabinogalactan II content was low in Vk2a (2%) compared with that in Ct50A1 (23%) and Ct50A2 (12%). The high molecular weight polymers were subjected to digestion with a beta-d-(1, 3)-galactanase-rich fraction from Driselase, oligomers were isolated by HPAEC, and their finer structures were determined by MALDI- and ES-qoToF-MS, linkage, and monosaccharide composition analyses. Vk2a consists of both a galacturonan core and a rhamnogalacturonan core rich in neutral side chains. The backbones of both Ct-polysaccharides consist mainly of RG-I regions with numerous neutral side chains dominated by galactosyl residues, whereas the homogalacturonan regions seem to be small. Differences in the chain lengths of the 6-linked galacto-oligosaccharides attached to the 3-linked galactan core could not be related to the differences in the potencies of the biological activities observed.

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Amino AcidsAnimalsAnti-Ulcer AgentsB-LymphocytesBixaceaeCells, CulturedComplement Fixation TestsComplement System ProteinsFemaleGalactansGlycosylationMagnetic Resonance SpectroscopyMiceMitogensMitosisMolecular WeightMonosaccharidesOceans and SeasPectinsStructure-Activity RelationshipVernoniaJournal ArticleResearch Support, Non-U.S. Gov't

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Cecilie Sogn Nergard, Hiroaki Kiyohara, James C Reynolds, Jane E Thomas-Oates, Tsukasa Matsumoto, Haruki Yamada, Trushar Patel, Dirk Petersen, Terje E Michaelsen, Drissa Diallo, Berit Smestad Paulsen. 2006. Structures and structure-activity relationships of three mitogenic and complement fixing pectic arabinogalactans from the malian antiulcer plants Cochlospermum tinctorium A. Rich and Vernonia kotschyana Sch. Bip. ex Walp.. https://doi.org/10.1021/bm050355g

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