State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China.
Molecules. 2022 Sep 5;27(17):5715. doi: 10.3390/molecules27175715.
In this study, the ultrasonic-assisted extraction of total coumarins from (Miq.) Maxim () via the combination of deep eutectic solvents (DESs) with cellulase pretreatment was carried out. Among the 15 kinds of DESs with choline chloride as hydrogen bond acceptors, the DES system of choline chloride/1,4-butanediol with a molar ratio of 1:4 showed the best extraction effect. First, single-factor experiments were performed using the following factors: liquid-solid ratio, pH, enzyme dosage and ultrasonic temperature. The Box-Behnken design (BBD) and response surface methodology (RSM) were employed to optimize the extraction conditions and obtain the following optimal parameter values for the extraction of coumarins from : liquid-solid ratio 14:1 mL/g, pH 5.0, enzyme dosage 0.2%, ultrasonic temperature 60 °C and ultrasonic time 50 min. Under these conditions, the extraction yield of total coumarins from could reach 2.65%, which was close to the predicted extraction yield of 2.68%. Furthermore, the contents of six coumarins, namely, umbelliferone, nodakenin, xanthotoxin, bergapten, imperatorin and decursin were determined to be 0.707 mg·g, 0.085 mg·g, 1.651 mg·g, 2.806 mg·g, 0.570 mg·g and 0.449 mg·g, respectively, using HPLC-MS after the optimization. In addition, the cell fragmentation of powder obtained using ultrasonic-assisted DES extraction with enzyme pretreatment was found to be the most comprehensive using scanning electron microscopy (SEM), which indicated the highest extraction efficiency for . Finally, the in vitro antioxidant activity of the extracts was evaluated via radical scavenging with 1,1-diphenyl-2-picrylhydrazyl (DPPH), which showed that ultrasonic-assisted DES extraction with enzyme pretreatment exhibited significant antioxidant activity with DPPH radical scavenging of up to 97.90%. This work developed a new and efficient extraction method for coumarins.
本研究采用超声辅助提取，结合深共晶溶剂（DESs）与纤维素酶预处理，从（Miq.）Maxim（）中提取总香豆素。在以氯化胆碱为氢键供体的 15 种 DESs 中，氯化胆碱/1,4-丁二醇摩尔比为 1:4 的 DES 体系表现出最佳的提取效果。首先，通过单因素实验，考察了液固比、pH 值、酶用量和超声温度等因素。采用 Box-Behnken 设计（BBD）和响应面法（RSM）优化提取条件，得到从中提取香豆素的最佳参数值为：液固比 14:1 mL/g、pH 值 5.0、酶用量 0.2%、超声温度 60°C、超声时间 50 min。在此条件下，从中提取总香豆素的提取率可达 2.65%，接近预测提取率 2.68%。此外，通过 HPLC-MS 测定，优化后得到 6 种香豆素的含量分别为：伞形酮 0.707 mg·g、蛇床子素 0.085 mg·g、花椒毒素 1.651 mg·g、佛手柑内酯 2.806 mg·g、欧前胡素 0.570 mg·g 和花椒毒素 0.449 mg·g。此外，通过扫描电子显微镜（SEM）观察发现，经超声辅助 DES 提取与酶预处理后，的细胞破碎最为完全，表明提取效率最高。最后，通过 1,1-二苯基-2-苦基肼基（DPPH）自由基清除法评价提取物的体外抗氧化活性，结果表明，超声辅助 DES 提取与酶预处理具有较高的抗氧化活性，DPPH 自由基清除率高达 97.90%。本研究开发了一种新的、有效的香豆素提取方法。
