title: Isolation and structural characterization of a novel antioxidant mannoglucan from a marine bubble snail, Bullacta exarata (Philippi).
abstract: Bullacta exarata is one of the most economically important aquatic species in China, noted for not only its delicious taste and nutritional value, but also for its pharmacological activities. In order to explore its potential in medical applications, a mannoglucan designated as BEPS-IB was isolated and purified from the foot muscle of B. exarata after papain digestion. Chemical composition analysis indicated BEPS-IB contained mainly D-glucose and D-mannose in a molar ratio of 1:0.52, with an average molecular weight of about 94 kDa. The linkage information was determined by methylation analysis, and the anomeric configuration and chain linkage were confirmed by IR and 2D NMR. The results indicated BEPS-IB was composed of Glcp₆Manp heptasaccharide repeating unit in the backbone, with occasional branch chains of mannose residues (14%) occurring in the backbone mannose. Further antioxidant assay indicated BEPS-IB exhibited positive antioxidant activity in scavenging superoxide radicals and reducing power. This is the first report on the structure and bioactivity of the mannoglucan from the B. exarata.
authors.affiliation: College of Biosystem Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Xihu District, Hangzhou 310058, China. yqhu@zju.edu.cn.
authors.forename: Donghong
authors.initials: D
authors.lastname: Liu
authors.forename: Ningbo
authors.initials: N
authors.lastname: Liao
authors.forename: Xingqian
authors.initials: X
authors.lastname: Ye
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Hu
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zhong
authors.forename: Jianyong
authors.initials: J
authors.lastname: Wu
authors.forename: Shiguo
authors.initials: S
authors.lastname: Chen
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002681:China; D005947:Glucose / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008358:Mannose / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D012908:Snails / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D011134:Polysaccharides; C493955:mannoglucan; D005947:Glucose; D008358:Mannose