【摘要】 通过单因素和正交试验研究超声波辅助乙醇提取玄参总三萜,讨论了料液比、乙醇体积分数、超声波时间、温度等因素对提取效果的影响,用大孔树脂进行纯化并用齐墩果酸对照品测定含量,考察了纯化后的总三萜提取物对羟基自由基(·OH)的清除效果,以没食子酸和Vc为对照品,对总三萜提取物抑制油脂氧化进行评估。结果表明:在超声波功率250 W、70℃下,选择70%乙醇为提取剂,料液比为1∶30(g∶mL),超声波提取40 min后,2.0 g玄参原料经过2次提取,5次平行实验总三萜得率平均值为2.56%,纯化后齐墩果酸质量分数为88.50%。玄参总三萜提取物对羟基自由基的清除率50%时即IC50所对应的总三萜质量浓度为38 mg/L,当在40℃烘箱中强化放置360 min后,总三萜质量浓度为12 mg/L的提取物对植物油的保护率为20.5%,对动物油的保护率为29.0%,相同条件下玄参总三萜提取物对动物油的抗氧化效果强于没食子酸和Vc,对植物油的抗氧化效果与没食子酸和Vc相当。更多还原

【Abstract】 Total triterpenoids was extracted from Scrophularia ningponesis Hemsl. with ethanol and ultrasonic-assisted. The influence factors such as material-to-liquid ratio( g ∶ mL),ethanol volume fraction,ultrasonic extracting time and temperature were investigated based on single factor and orthogonal test. The total triterpenoids extract was purified by macro-porous resin and analyzed with oleanic acid. Research on hydroxyl radicals scavenging of purified total triterpenoids extracts was carried out. The antioxidation to oils and fats of purified total triterpenoids extracts were evaluated and compared with gallic acid and Vc. The results showed that the optimal extracting conditions were obtained as follows: 70% ethanol,1 ∶ 30( g ∶ mL) material-to-liquid ratio,40 min ultrasonic extracting time at 250 W and 70 ℃,twice extraction. Under above conditions,the extracts yield was 2. 56% and the content of oleanic acid in purified total triterpenoids extracts was 88. 50%. The purified total triterpenoids extracts exhibited excellent ability to remove·OH and the oleanic acid concentration of IC 50 to·OH was 12 mg / L. When antioxidation test was carried out at the condition of being kept in oven at 40 ℃ for 360 min,the protection rate was 20. 5% to oil and 29. 0% to fat,respectively. The antioxidating effect of purified total triterpenoids extracts was better than that of gallic acid and Vc to oils and almost the same as gallic acid and Vc to fats,respectively.更多还原