超声辅助提取甘青虎耳草总黄酮工艺及其抑菌作用

目的：研究甘青虎耳草(Saxifraga tangutica Engl.)总黄酮的提取工艺及其抑菌作用。方法：用正交试验超声波辅助乙醇提取总黄酮；用琼脂扩散法和肉汤倍比稀释法研究不同质量浓度总黄酮提取物对6种供试菌的抑菌作用。结果：方差分析得各因素影响的顺序为提取次数＞乙醇体积分数＞超声时间＞料液比，最佳工艺为提取50℃、超声功率100W、乙醇体积分数80%、料液比1:25(g/mL)、超声时间35min、提取4次，在此条件下提取率达81.73mg/g；抑菌试验显示总黄酮提取物对细菌均有抑制作用，对金黄色葡萄球菌、枯草杆菌、大肠杆菌的最小杀菌质量浓度分别为0.156、0.313、0.625mg/mL；对酵母菌的抑制作用较弱；对霉菌没有抑制作用。结论：本实验结果可为甘青虎耳草总黄酮提取工艺的确定及在抑菌方面的应用提供实验依据。

Ultrasonic-Assisted Extraction and Antibacterial Activity of Total Flavonoids from Whole Plants of Saxifraga tangutica Engl.

Objective: To investigate the extraction and antioxidant activity of total flavonoids from whole plants of Saxifraga tangutica Engl.Methods: Orthogonal array design was employed to optimize extraction conditions.The antibacterial effect of total flavonoid extract at different concentrations on 6 strains was evaluated by agar diffusion and broth dilution methods.Results: According to the results of analysis of variance,four extraction parameters could be ranked in decreasing order of their effect on extraction efficiency as follows: extraction number > ethanol concentration > ultrasonic treatment time > material-to-liquid ratio.The optimal extraction conditions were ethanol concentration of 80%,material-to-liquid ratio of 1:25(g:mL),ultrasonic treatment time of 35 min,repeated ultrasonic treatment number of 4,ultrasonic power of 100 W and extraction temperature of 50 ℃.Under these conditions,the extraction efficiency of total flavonoids was 81.73 mg/g.Total flavonoids from whole plants of Saxifraga tangutica Engl.had inhibitory effect on all tested strains.The minimum inhibitory concentrations were 0.156,0.313 mg/mL and 0.625 mg/mL against Staphyloccus aureus,Bacillus subtilis and Escherichia coli,respectively.The anti-yeast activity was weak.No inhibitory effect on mold was found.Conclusion: This study can provide experimental references for further development and utilization of Saxifraga tangutica Engl.