响应面法优化豫西山茱萸叶黄酮的提取及其抑菌和抗氧化活性

Extraction process optimization of flavonoids from Cornus officinalis leaves and its antibacterial and antioxidant activity

通过响应面法对山茱萸叶黄酮的提取工艺进行优化,并对其体外抑菌和抗氧化活性进行研究。经优化后,山茱萸叶黄酮在超声功率290 W、液料比31∶1(mL/g)、乙醇体积分数61%、提取时间23 min的工艺条件下提取得率最高,达到6.31%,与模型预测值相符。抑菌实验结果表明山茱萸叶黄酮对沙门氏菌有较强的抑菌作用,对绿脓杆菌、金黄色葡萄球菌和中华根霉有较弱的抑菌作用,说明山茱萸叶黄酮对细菌有较强的抑菌作用,对真菌有较弱的抑菌作用。山茱萸叶黄酮浓度为1.2 mg/mL时其对DPPH自由基的清除率为77.24%,对羟基自由基的清除率达到83.54%;山茱萸叶黄酮清除DPPH自由基和羟基自由基的IC50分别为0.699和0.631 mg/L,表明山茱萸叶黄酮具有较强的抗氧化活性。

The extraction process of flavonoids from Cornus officinalis leaves was optimized by response surface methodology,and its antioxidant and antibacterial activity were studied in vitro.The extraction rate of flavonoids was the highest under the conditions of ultrasonic power 290 W,solvent to solid ratio 31∶1(mL/g),ethanol concentration 61% and extraction time 23 min,reaching 6.31%,which was consistent with the predicted value of the model.The results showed that flavonoids from C.officinalis leaves had a strong antibacterial activity against Salmonella typhimurium and weak antimicrobial activity against Pseudomonas aeruginosa,Staphylococcus aureus and Rhizopus chinensis,indicating that the flavonoids had a strong inhibitory effect on bacteria and weak inhibitory effect on fungi.The clearance rates of DPPH radical and hydroxyl radical were 77.24% and 83.54%,respectively,when the concentration was 1.2 mg/mL.The IC50 of DPPH radical and hydroxyl radical were 0.699 and 0.631 mg/mL,respectively,which indicated that the flavonoids from C.officinalis leaves had strong antioxidant activity.