峨眉岩白菜总三萜纯化及活性分析

以峨眉岩白菜为研究对象，采用沉淀分级溶解法初步纯化其总三萜化合物并比较纯化前后总三萜抗氧化、抑菌和抑癌活性.结果表明：经4次冻干后，样品提取率从38.13 %降低到26.79 %，提取物中总三萜含量从48.58 %升高到70.99 %；纯化后的总三萜化合物总还原能力增强，对DPPH自由基的清除能力增强，IC50由0.32 mg·mL－1降低到0.27 mg·mL－1；峨眉岩白菜总三萜对铜绿假单胞杆菌和枯草芽孢杆菌均有一定的抑制能力，纯化后能提高总三萜对两种菌的敏感度；纯化后总三萜提取物对Hela细胞24和48 h的IC50从纯化前的102.5和69.00 μg·mL－1降低到59.01和28.56 μg·mL－1，对A549肺癌细胞24和48 h的IC50从纯化前的238.90 μg·mL－1和172.00 μg·mL－1降低到84.32 μg·mL－1和65.99 μg·mL－1.因此沉淀分级溶解法可适用于峨眉岩白菜总三萜的纯化，纯化后的总三萜体外抗氧化、抑菌活性和抑癌活性均有一定程度的提高.

Purification of total triterpenes from Bergenia emeiensis and comparison of the bioactivities before and after purification

In this study， precipitation fractionation dissolution method was used to purify the total triterpenes in Bergenia emeiensis and the antioxidant， anticancer as well as antibacterial activities were analyzed before and after purification. The results showed that after repeated freeze-dry， the content of triterpenes increased from 48.58% to 70.99% while the sample extraction rate lowered from 38.13% to 26.79%. The total reducing ability of the purified total triterpenes was promoted and the ability to scavenge DPPH free radicals was boosted with the IC50 changing from 0.32 mg·mL－1 to 0.27 mg·mL－1. The total triterpenes in Bergenia emeiensis could well inhibit Pseudomonas aeruginosa and Bacillus subtilis. After purification， inhibition zones of the total triterpenes on two strains enhanced. The IC50 to Hela cells was changed from 102.5 and 69.00 μg·mL－1 to 59.01 and 28.56 μg·mL－1 for 24 and 48 hours， respectively after purification. Moreover， the IC50 to A549 cells was changed from 238.90 and 172.00 μg·mL－1 to 84.32 and 65.99 μg·mL－1 for 24 and 48 hours， respectively. Therefore， the precipitation fractionation dissolution method can be applied to the purification of total triterpenes in Bergenia emeiensis and the purified total triterpenes exhibited a better antioxidant， anticancer and bacteriostatic activity in vitro.