title: Effect of acetylation on antioxidant and cytoprotective activity of polysaccharides isolated from pumpkin (Cucurbita pepo, lady godiva).
abstract: Acetylation of pumpkin (Cucurbita pepo, lady godiva variety) polysaccharide using acetic anhydride with pyridines as catalyst under different conditions was conducted to obtain different degrees of acetylation on a laboratory scale. Furthermore, antioxidant activities and cytoprotective effects of pumpkin polysaccharide and its acetylated derivatives were investigated employing various established in vitro systems. Results showed that addition of pyridine as catalyst could increase the degree of substitution, whereas volume of acetic anhydride had little effect. The acetylated polysaccharides in DPPH scavenging radical activity assay, superoxide anion radical activity assay and reducing power assay exhibited higher antioxidant activity than that of unmodified polysaccharide. H2O2-induced oxidative damages on rat thymic lymphocyte were also prevented by pumpkin polysaccharide and its acetylated derivatives and the derivatives presented higher protective effects. On the whole, acetylated polysaccharide showed relevant antioxidant activity both in vitro and in a cell system.
authors.affiliation: National Engineering Research Center for Fruits and Vegetables Processing, Beijing 100083, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Song
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Yuyu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Liusheng
authors.initials: L
authors.lastname: Duan
authors.forename: Chunli
authors.initials: C
authors.lastname: Zhou
authors.forename: Yuanying
authors.initials: Y
authors.lastname: Ni
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Liao
authors.forename: Quanhong
authors.initials: Q
authors.lastname: Li
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Hu
mesh_terms: D000107:Acetylation; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D028464:Cucurbita / Q000737:chemistry*; D019610:Cytoprotection / Q000187:drug effects*; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D051379:Mice; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D016166:Free Radical Scavengers; D011134:Polysaccharides; D006861:Hydrogen Peroxide
keywords: Acetylation; Antioxidant activity; Cytoprotective effect; Polysaccharide; Pumpkin