银耳碱提多糖的纯化、化学表征及其抗氧化作用的研究(英文)

Purification,Chemical Characterization and Antioxidant Activity of Alkaline Solution Extracted Polysaccharide from Tremella fuciformis Berk

研究银耳孢子发酵物中的多糖类化学成分,并探讨了分离得到的一个多糖组分的抗氧化活性。银耳孢子发酵粉用热水煮提除去水溶性组分后,再采用0.5 mol.L-1的氢氧化钠溶液提取,Sevage法除蛋白,用乙醇沉淀得到粗多糖。粗多糖经DEAE-32-纤维素和Sephadex G-200分离纯化得到分布均一的多糖TFBP-A。糖组成分析显示,TFBP-A单糖组成为:甘露糖:半乳糖:葡萄糖,摩尔比为90∶5∶5;HPGPC测定TFBP-A分子量为58962。TFBP-A的抗氧化活性实验显示:在H2O2引起的红细胞溶血试验中,以蒸馏水抑制率为0%计算,TFBP-A抑制率为78.6%;在超氧阴离子自由基的清除作用实验中,TFBP-A最高抑制率为53%;在清除羟基自由基实验中,TFBP-A的EC50为0.191 mg.mL-1。从银耳孢子发酵物中用碱液提取得到的多糖组分TFBP-A为酸性杂多糖,重均分子量为58962,且具有一定的抗氧化活性。

Tremella fuciformis Berk（TFB） is widely distributed in southwest China.Its sporocarps are used as traditional Chinese medicine for nourishing yin and promoting fluid production,moistening lung and relieving cough.In this study,a polysaccharide with the molecular weight of 58962,named TFBP-A,was isolated from the fermentation product of TFB by alkaline solution.Its antioxidant activity was evaluated using three in vitro assay experiments including hydroxyl free radicals scavenging,superoxide anion free radicals elimination and red cells hemolysis inhibition.TFBP-A showed scavenging activity to hydroxyl free radicals and the EC50 was 0.191 mg·mL-1;while it could also eliminate superoxide anion free radicals and the highest eliminating ratio was 53.0%;it could still inhibit red cells hemolysis aroused by H2O2 and the inhibition ratio was 78.6%.These results suggest that TFBP-A has certain antioxidant activity.