红花紫荆叶总黄酮提取工艺及其抑菌和抗氧化活性

研究了超声波提取红花紫荆(Bauhinia blakeana Dunn)叶黄酮的条件及其抗菌、抗氧化的性能。结果表明,经过正交试验分析,总黄酮最佳提取工艺为乙醇体积分数60%,超声时间45 min,超声温度70℃,料液比1∶20(m∶V),该条件下总黄酮提取率为4.11%。红花紫荆叶总黄酮对大肠杆菌、金黄色葡萄球菌、白色念珠菌均有抑菌效果,对金黄色葡萄球菌的抑菌效果最好,对青霉的抑菌效果不明显;红花紫荆叶总黄酮对金黄色葡萄球菌和大肠杆菌最小抑菌溶度为0.025 g/m L,对白色念珠菌最小抑菌浓度为0.05 g/m L,对青霉最小抑菌浓度为0.6 g/m L。红花紫荆叶总黄酮对羟自由基、超氧阴离子自由基、亚硝酸盐均具有一定的清除作用,在浓度0.5~2.5 mg/m L的范围内,清除能力随着浓度的增加而增强,且强于阳性对照维生素C的清除能力,抗氧化能力较强。

Extraction,Antibiosis and Antioxidant Activity Analysis of Total Flavonoids from Bauhinia blakeana Dunn Leaves

The conditions of ultrasonic extraction of Bauhinia blakeana Dunn leaf flavonoids and its antibiosis and antioxidant capabilities were studied. The results showed that the optimum extraction process of total flavonoids was ethanol concentration 60%,ultrasonic time of 45 min,ultrasonic temperature 70℃and solvent ratio 1:20(m:V ) by orthogonal experiment,under opti-mal conditions the extraction rate of 4.11%. The total flavonoids of Bauhinia blakeana Dunn leaf had antibacterial effect a-gainst E. coli,Staphylococcus aureus,Candida albicans,and its antibacterial effect of Staphylococcus aureus was best,the effect of Penicillium was not obvious. The minimum inhibitory concentrations for S. aureus,E. coli was 0.025 g/mL,the minimum in-hibitory concentration for C.albicans and Penicillium were 0.05 g/mL and 0.6 g/mL. The total flavonoids from Bauhinia blakeana Dunn leaves had certain scavenging ability on hydroxyl free radicals,superoxide anion free radicals and nitrite,and at the range of 0.5~2.5 mg/mL,the concentration increase,the scavenging capacity enhance,it has stronger antioxidant activity than positive control VC.