总评“归一值”优选黄芩中黄酮类成分的提取工艺

Optimum extraction technology of flavonoids from Scutellaria Baicalensis by overall desirability

优选回流提取法和超声提取法对黄芩中4种黄酮类成分的提取条件,并对其进行比较。以黄芩苷、汉黄芩苷、黄芩素、汉黄芩素得率的总评"归一值"为评价指标,采用星点设计-效应面法考察乙醇浓度、液料比、提取时间对4种成分得率的影响,并优选出最佳提取条件。结果显示,回流提取法最佳提取工艺为乙醇浓度79%;液料比为11∶1;提取时间为2 h;提取2次,此条件下黄芩苷、汉黄芩苷、黄芩素、汉黄芩素平均得率分别为12.51%、3.48%、0.84%、0.24%,总评"归一值"OD平均值为0.94,与预测值的偏差为0.05%;超声提取法中最优提取工艺为乙醇浓度为79%,液料比为22∶1,提取时间为51 min,提取1次,该条件下测得黄芩苷、汉黄芩苷、黄芩素、汉黄芩素平均得率分别为8.30%、2.53%、0.53%、0.19%,总评"归一值"OD为0.98,与预测值的偏差为0.01%。回流提取黄芩中4种黄酮类成分的得率远大于超声提取法。说明经过星点设计-效应面法优化的回流提取法提取工艺稳定可行,预测性好。且该方法简单易操作、成本低,可为黄芩中黄酮类成分的有效利用和提取工艺的研究提供参考。

Optimum extraction conditions of four flavonoids from Scutellaria baicalensis by reflux extraction and ultrasonic extraction,and the two methods are compared. Taking the overall desirability of the yield of baicalin,wogonoside,baicalein and wogonin as the evaluation index,the effects of ethanol concentration,liquid-to-material ratio and extraction time on the yield of the four components were investigated by central composite design-response surface methodology,and the optimum extraction conditions were selected. The optimum reflux extraction process was 79% ethanol concentration,11∶1 liquid-material ratio,2 h extraction time and 2 times extraction. Under these conditions,the average yield of baicalin,wogonoside,baicalein and wogonin were 12.51%,3.48%,0.84% and 0.24%,respectively. The average OD value of total evaluation was 0.94,and the deviation from the predicted value was 0.05%. The optimum ultrasonic extraction process was ethanol concentration 79%,liquid-material ratio 22∶1,extraction time 51 min,extraction time 1 time,under this condition,the average yield of baicalin,wogonoside,baicalein and wogonin were 8.30%,2.53%,0.53%,0.19%,OD mean value was 0.98,and the deviation from the predicted value was 0.01%. The yield of reflux extraction of four flavonoids from Scutellaria baicalensis is much higher than that of ultrasonic extraction,so reflux extraction is better than ultrasonic extraction in this experiment. The reflux extraction process optimized by central composite design-response surface methodology is stable,feasible and predictable. The method was simple,easy to operate and low cost. It could provide a reference for the effective utilization of flavonoids in Scutellaria baicalensis and the study of extraction technology.