匙羹藤粗多糖的提取及其清除羟自由基活性研究

Study on Polysaccharides Extraction and Ability to Scavenge Hydroxyl Radicals from Gymnema sylvestre

目的:研究匙羹藤粗多糖的水提法优化工艺和清除羟自由基活性。方法:采用苯酚-硫酸法测定多糖含量,以多糖得率为考察指标,在单因素试验结果的基础上,进行正交试验设计,考察温度、时间、固液比、提取次数等因素对多糖得率的影响。采用水杨酸法考察匙羹藤粗多糖清除羟自由基活性。结果:影响多糖得率最主要的因素是温度,其次是提取时间。水提法优化工艺条件为温度100℃,时间3h,固液比1:15,提取次数2次。此条件下多糖得率达2.21%,粗多糖中多糖含量为25.57%。匙羹藤粗多糖具有清除羟自由基能力,并且其清除能力与浓度有明显的量效关系,匙羹藤粗多糖浓度为3.5mg/ml时清除率达50%,浓度为12mg/ml时其清除率高达94.42%。结论:该优化工艺可用于匙羹藤粗多糖的提取,高浓度匙羹藤粗多糖具有较好的抗氧化活性。

Objective： To study the polysaccharides extraction technology and antioxidant activity from Gymnema sylvestre. Methods： The content of polysaccharides of Gymnema sylvestre was determined by the method of phenol-sulphate acid. On the basis of single factors tests, the four factors including temperature, time, solid-liquid ratio and the extraction times on the yield of the polysaccharides were studied by orthogonal test design. The salicylic acid method was used to inspect the capability to scavenge hydroxyl radicals of the polysaccharides from Gymnema sylvestre. Results： The results showed that temperature is the most important factor for the extraction percentage of the polysaccharides, and the time unit is the second. The optimal extraction technology conditions are： temperature 100 ℃, extraction time 3 h, solid-liquid ratio 1：15 and extraction times 2 times. The yield of the polysaccharides is 2.21%, and the content of polysaccharides 25.57%. The polysaccharides have good capability to scavenge the hydroxyl radicals, and the scavenging capability is obviously related to the concentrations. The scavenging rate is 50% at the concentration of 3.5 mg/ml, while the scavenging rate is 94.42% at the concentration of 12 mg/ml. Conclusion： This extraction technology can be used for the extraction of the polysaccharides from Gymnema sylvestre. The polysaccharides have good antioxidant activity at a high concentration.