碱提白芨粗多糖脱蛋白方法比较及抗氧化活性

Comparison of deproteinization methods of alkaline-extracted crude polysaccharide from Bletilla striata and its antioxidant activity

摘要:

以碱提白芨粗多糖(BSP-A)为对象,对比三氯乙酸(TCA)法、TCA+正丁醇法、大孔树脂AB-8吸附法、木瓜蛋白酶法、Sevage法和三相分离法脱除粗多糖中蛋白的效果。以多糖回收率和蛋白脱除率作为重要指标,并探讨多糖结构和生物活性,确定更适用于多糖纯化的方法。结果表明,Sevage法、蛋白酶法和三相分离法对多糖的保留率达到80%以上,反应相对温和；TCA法、TCA+正丁醇法、大孔树脂AB-8吸附法脱蛋白效果最佳,最高能达到90%。不同的脱蛋白处理,对白芨多糖的分子量影响轻微；而三相分离法和TCA+正丁醇法,影响了样品中甘露糖和葡萄糖的组成比例。6种方法均对BSP-A的Zeta电位和红外光谱特征产生了一定的影响,其中蛋白酶法和Sevage法能较好的保留白芨多糖的抗氧化活性。总的来说,Sevage法是一种对多糖结构和活性保留较好的一种多糖脱蛋白方法,但脱蛋白效率不佳,可作为白芨多糖脱除游离蛋白的有效手段之一。

Abstract:

The alkaline-extracted crude polysaccharide from Bletilla Striata (BSP-A) was used to compare the effect of protein removal by TCA method, TCA+n-butanol method, macroporous resin AB-8 adsorption method, papain method, Sevage method, and three-phase separation method. The polysaccharide retention and protein removal yield were used as important indicators, and the polysaccharide structure and biological activity were explored to determine a more suitable method for polysaccharide purification. The results showed that Sevage, papain, and three-phase separation methods could retain more than 80% of polysaccharides with relatively mild reactions. TCA method, TCA+n-butanol method, and macroporous resin AB-8 adsorption method had the best results in deproteinization, of which the highest could reach 90%. Different deproteinization methods slightly affected the molecular weight of BSP-A, while the three-phase separation method and TCA+n-butanol method affected the composition ratio of mannose and glucose of BSP-A. These six methods affected the zeta potential and FT-IR characteristics of BSP-A, among which the papain and Sevage methods could better retain the antioxidant activity. In general, Sevage method was a polysaccharide deproteinization method with good retention of polysaccharide structure and activity but low deproteinization efficiency, and it can be one of the compelling methods to remove free protein from BSP-A.