College of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
Bioresour Technol. 2010 Jun;101(12):4729-32. doi: 10.1016/j.biortech.2010.01.125. Epub 2010 Feb 13.
Two water-soluble extracellular polysaccharides, ETW1 and ETW2, were isolated from the marine bacterium Edwardsiella tarda by ion-exchange and size-exclusion chromatography, and their structures were investigated. ETW1 and ETW2 are mannans, with molecular weights of about 29 and 70kDa, respectively. The main chain of the polysaccharides consists of (1-->3)-linked mannose residues, and branched mannose linkages were also detected. The branch points are located at the C-2 and C-6 positions of the (1-->3)-linked mannose residues. The side chains are composed of (1-->2)-linked mannose residues and (1-->)-linked mannose residues. Antioxidant properties of the two extracellular polysaccharides were evaluated with hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging activities and lipid peroxidation inhibition in vitro, and results showed that ETW1 and ETW2 had good antioxidant and hydroxyl and DPPH radicals scavenging activities. ETW1 exhibited higher antioxidant activity than ETW2, and could be a potential source of antioxidant and used as possible food supplement or ingredient in the pharmaceutical industry.
从海洋细菌迟缓爱德华氏菌中分离出水溶性胞外多糖 ETW1 和 ETW2，并用离子交换和凝胶渗透色谱法对其结构进行了研究。ETW1 和 ETW2 是甘露聚糖，分子量分别约为 29 和 70kDa。多糖的主链由 (1-->3)-连接的甘露糖残基组成，并且还检测到支化的甘露糖连接。支化点位于 (1-->3)-连接的甘露糖残基的 C-2 和 C-6 位置。侧链由 (1-->2)-连接的甘露糖残基和 (1-->)-连接的甘露糖残基组成。通过羟基和 1,1-二苯基-2-苦基肼 (DPPH) 自由基清除活性和体外脂质过氧化抑制作用评估了两种胞外多糖的抗氧化特性，结果表明 ETW1 和 ETW2 具有良好的抗氧化和羟基和 DPPH 自由基清除活性。ETW1 表现出比 ETW2 更高的抗氧化活性，可能是抗氧化剂的潜在来源，并可作为食品补充剂或药物成分在医药行业使用。
