具鞘微鞘藻多糖提取、结构分析及抗氧化活性研究

Studies on Extraction,Structure Analysis and Antioxidant Property of Polysaccharide from Microcoleus vaginatus

具鞘微鞘藻(Microcoleus vaginatus)是广泛分布于荒漠区土壤中的一种丝状蓝藻.采用水提醇沉法分别提取具鞘微鞘藻胞内、外多糖,测定其提取率、产率和抗氧化活性,并对其结构进行初步解析.结果表明:胞内、外多糖的提取率最高分别为3.46%和77.98%,多糖产率最高分别为83.67%和50.76%.考马斯亮蓝染色法检测蛋白含量可低至3.26%.具鞘微鞘藻胞内、外多糖体外能够有效地清除O^2-·、DPPH·和·OH及微弱地螯合Fe^2+.傅立叶红外光谱(IR)分析表明:具鞘微鞘藻多糖中普遍存在分子间的氢键,且其中的单糖多以吡喃糖甙的形式存在,糖苷键类型为α-型.

The Microcoleus vaginatus was screened from the desert soil,the intracellular polysaccharides(IPS)and exopolysaccharide(EPS)were obtained via water extraction and ethanol precipitation method,the extraction rate,yield rate and antioxidant activity were determined respectively.The results proved that the highest extraction rates of intracellular polysaccharide and exopolysaccharide were 3.46% and 77.98% respectively,the highest yield rates of intracellular polysaccharide and exopolysaccharide were 83.67% and 50.76%,respectively.Protein content measured by Coomassie brilliant blue staining method was as low as 3.26%.The polysaccharides can effectively remove the superoxide anion radical,DPPH free radical and hydroxyl radical and weakly chelate ferrous ions in vitro.The analysis of Fourier infrared spectroscopy showed that the hydrogen bonding between molecules were prevalent in the M.vaginatus polysaccharides,and the monosaccharides were present in the form of pyranoside,and the glycosidic bond is α-type.