响应曲面法优化白花前胡总香豆素提取及抑菌和抗氧化活性

Optimization of Extraction Technology of Total Coumarins from Peucedanum praeruptorum Dunnby Response Surface Method and Its Antibacterial and Antioxidant Activities

以白花前胡香豆素为原料,在单因素实验基础上,响应面法确定超声预处理-乙醇回流法提取前胡总香豆素的最佳工艺条件;质量浓度倍减法检测总香豆素对6种植物病源菌的抑制效果;采用清除自由基法进行总香豆素抗氧化活性评价测定。结果表明,当回流时间2 h、乙醇质量浓度59%、料液比1∶40 g/mL、回流温度81℃时,白花前胡香豆素提取率最高为(4.249±0.03)%。总香豆素对病菌的抑制效果与其浓度成量效关系,最高测试浓度下抑菌活性次序为:水稻稻瘟病菌>马铃薯干腐病菌>苹果炭疽病菌>苹果腐烂病菌>番茄灰霉病菌>尖孢镰刀病菌。实验所得水稻稻瘟菌和马铃薯干腐菌的最小抑菌浓度(MIC)为3.125mg/mL,苹果炭疽菌、苹果腐烂菌和番茄灰霉菌的MIC为6.25 mg/mL,尖孢镰刀菌MIC为12.5 mg/mL。体外抗氧化活性实验表明总香豆素具有较好抗氧化作用,自由基清除率与浓度呈剂量-效应关系,且总香豆素对羟基自由基的清除力最为显著。

The extraction of total coumarins from Peucedanum praeruptorum Dunn was studied with the ultrasound pretreatment-alcohol reflux method.Based on single-factor experiments,the optimal extraction conditions of total coumarins were determined by the response surface methodology.The two-dilution method was used to detect the inhibitory effects of the total coumarins on six plant fungal pathogens.And the antioxidant activities were evaluated by free radical scavenging tests.The results showed that the optimum conditions were shown as follows:extracting time of 2 hours,ethanol concentration of 59%,solid-liquid ratio of 1∶40 g/mL,extracting temperature of 81℃.Under the above conditions,the total coumarins of Peucedanum praeruptorum Dunn was(4.249±0.03)%.And there was a dose-effect relationship between the concentration of coumarins and antibacterial activity.The order of inhibition under the highest testing concentration was Pyricularia Grisea>Fusarium sulphureum>Colletotrichum gloeosporioide>Cytosporasp>Botrytis cinerea>Fusarium oxysporum.The minimal inhibitory concentration(MIC)was as follows:3.125 mg/mL to Pyricularia Grisea and Fusarium sulphureum,6.25 mg/mL to Colletotrichum gloeosporioide,Cytosporasp and Botrytis cinerea,and 12.5 mg/mL to Fusarium oxysporum.Moreover,the total coumarins had good scavenging effects on tested free radicals,and the scavenging effect had a dose-effect relationship.The scavenging ability to hydroxyl radical was the most significant.