Structural elucidation and immune-enhancing activity of peculiar polysaccharides fractioned from marine clam Meretrix meretrix (Linnaeus). (1st December 2018)

• Record Type: Journal Article
• Authors: Wang, Lingchong; Chen, Liye; Li, Junsong; Di, Liuqing; Wu, Hao
• Is Part Of: Carbohydrate polymers. Volume 201(2018)
• Page Start: 500
• Page End: 513
• Publication Date: 2018-12-01
• Subjects: M. meretrix -- Polysaccharide -- Structure elucidation -- Immune activity; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2018.08.106
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: Highlights: Two polysaccharides of MMP-2 and MMP-3 are fractioned from marine clam M. meretrix . MMP-2 and MMP-3 belong to gulcomannan and gulcogalactan homologs. Their chemical structures are α(1→4)–glucan branched with Man or Gal. MMP-2 and MMP-3 can stimulate splenocyte proliferation and cytokines secretion. The bioactivity perhaps is correlated to their peculiar structures. Abstract: The marine clam Meretrix meretrix was subjected to extraction with a combined procedure of water decoction, ethanol precipitation, and deproteinization to yield a water-soluble polysaccharide coded as MMP. The product was fractionated with DEAE-52 cellulose and resulted in two soluble fractions designated as MMP-2 and -3. The structures of the fractions were determined by chemical and physicochemical analysis, and their immunomodulation activities and cytokine production were assayed by lymphopoiesis. Results showed that MMP-2 and -3 were glucomannan and glucogalactan homologs, respectively. They possess average molecular masses of 272 and 257 kDa, respectively, and were elucidated as branched copolymers, elaborated as α(1→4)–glucan branching with mannose or galactose via β(1→6)-linkage. Bioassay indicated that MMP-2 and -3 held moderate potentials in restoring immune function because they augment splenocyte proliferation and enhance the cytokine secretion of lymphocytes dose-dependently. We speculated that their bioactivities are closely correlated with their peculiar structures.