School of Food Science and Biotechnology, Zhejiang Gongshang University, 18 Xuezheng Street, Xiasha, Hangzhou, Zhejiang 310018, PR China.
College of Tourism & Food, Shanghai Business School, Shanghai 200235, PR China.
Food Chem. 2017 Jan 15;215:76-83. doi: 10.1016/j.foodchem.2016.07.151. Epub 2016 Jul 29.
In order to improve the bioactivities of the polysaccharide from Enteromorpha prolifera (PE), crude PE (Mw 1400kDa) was degraded to low molecular weight polysaccharide (44kDa) in the presence of hydrogen peroxide/ascorbic acid, followed by carboxymethylation. The reaction conditions for carboxymethylation of degraded polysaccharide (DPE) were optimized by Response Surface Methodology. The carboxymethyled degraded polysaccharide (CDPE) obtained under optimized conditions, with a degree of carboxymethylation of 0.849, was characterized by FT-IR and (13)C NMR. The molecular weight of CDPE was measured to be 53.7kDa. CDPE was evaluated for its antioxidant activity by determining the ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals, and by determining the ferric reducing power. The antioxidant activity of CDPE was found to be greatly improved in comparison with degraded polysaccharide (DPE) and crude polysaccharide from Enteromorpha prolifera (PE).
为了提高浒苔多糖的生物活性，在过氧化氢/抗坏血酸存在的条件下，将粗浒苔多糖（Mw 1400kDa）降解为低分子量多糖（44kDa），然后进行羧甲基化。采用响应面法对降解多糖（DPE）的羧甲基化反应条件进行了优化。在优化条件下得到的羧甲基化降解多糖（CDPE）的取代度为 0.849，采用傅里叶变换红外光谱（FT-IR）和（13）C 核磁共振（NMR）对其进行了表征。CDPE 的分子量测定为 53.7kDa。通过测定清除 1,1-二苯基-2-苦基肼（DPPH）、羟基和超氧阴离子自由基的能力以及铁还原能力来评价 CDPE 的抗氧化活性。与降解多糖（DPE）和浒苔粗多糖（PE）相比，CDPE 的抗氧化活性有了显著提高。
