本文研究了香椿老叶中总黄酮的提取工艺，提取液中总黄酮的得率以芦丁为对照品进行校正。先利用复合酶水解香椿老叶中的纤维素和果胶，探究出最佳酶解条件为复合酶2(果胶酶:纤维素酶=2:1)，酶用量为2.00%(W/V)，酶解时间40 min，酶解温度45 ℃，上清液中总黄酮得率为2.49%。再进行超声辅助提取，采用通过单因素实验和Box-Behnken实验对乙醇体积比、超声功率、超声时间、超声温度4个条件进行优化，各项方差分析表明影响香椿老叶中总黄酮得率的顺序依次为：超声功率>乙醇体积分数>提取温度>提取时间，再根据回归方程预测最佳提取条件。在采用乙醇体积分数60%、超声功率227 W、提取温度53.00 ℃、提取时间51 min条件下，香椿老叶总黄酮得率为3.85%，与预测值仅相差0.03%，表明工艺参数准确可靠。

In this wok, the extraction method of total flavonoids from old leaves of Toona sinensis was studied. Firstly, cellulose and pectin in the old leaves of Toona sinensis were hydrolyzed by complex enzymes, and the optimal enzymatic hydrolysis condition was found to be complex enzyme 2 (pectinase: cellulase=2:1), with an enzyme dosage of 2.00% (W/V), enzymatic hydrolysis time of 40 min, enzymatic hydrolysis temperature of 45 ℃, and the total flavonoids yield in the supernatant was 2.49%. Ultrasonic assisted extraction was performed later. The single factor experiment and the Box Behnken were used to optimize the ethanol volume ratio, ultrasonic power, ultrasonic time, ultrasonic temperature. The variance analysis showed that the yield of total flavonoids from old leaves of Toona sinensis was affected by following: the ultrasonic power > ethanol concentration > extraction temperature > extracting time. According to the regression equation, the best extraction conditions were predicted. Under the conditions of ethanol volume fraction of 60%, ultrasonic power of 227 W, extraction temperature of 53.00 ℃ and extraction time of 51 min, the total flavonoids yield of old leaves of Toona sinensis was 3.85%, which was only 0.03% different from the predicted value, indicating that the process parameters were accurate and reliable.

贵州省科学技术基金项目(黔科合J字[2014]2160)；铜仁市科技局科技计划项目(铜市科研(2013)10-13)