C_2H_5OH-(NH_4)_2SO_4双水相萃取太行菊总黄酮及其抑菌活性

Extraction of flavonoids from Opisthopappus taihangensis(Ling) Shih by C_2H_5OH-(NH_4)_2SO_4 aqueous two-phase system and the antibacterial activity

试验优化了太行菊总黄酮(FFO:Flavonoids from Opisthopappus taihangensis)双水相萃取体系并研究其抑菌活性。超声波辅助C_2H_5OH-(NH_4)_2SO_4双水相萃取FFO,依据Design-Expert8.0(Box-Benhnken)试验设计原理,以总黄酮萃取率为响应值进行方差分析,获取多元二次线性回归方程;采用K-B纸片扩散法测定6种供试菌种的抑菌圈直径,对比MIC和MBC确定其抑菌活性。23 g/mL C_2H_5OH-17 g/mL (NH_4)_2SO_4双水相萃取体系下FFO萃取率最高。响应面试验方差分析表明,pH和NaCl的浓度对萃取率的影响差异显著;最优双水相萃取体系:pH7.76、粗提液质量分数是19.35%、NaCl质量分数为2.38%,萃取率Y极大值为96.68%(P=0.994);FFO对枯草芽孢杆菌抑制作用最强,高剂量作用下抑菌率可达98.57%,MIC为1.56 mg/mL;对沙门氏菌、金黄色葡萄球菌和大肠杆菌抑制作用次之,对青霉和黑曲霉抑制作用最弱。

The extraction system of flavonoids from Opisthopappus taihangensis(Ling) Shih in aqueous two-phase system was optimized and its antibacterial activity was studied. Ultrasonic was used to assist C2H5OH-(NH4)2SO4 aqueous two-phase extraction of FFO, based on Design-Expert 8.0(Box-Benhnken)experimental design principles, the three factors and three levels of response surface analysis method was used with total flavonoids extraction rate as response values to obtain multivariate quadratic linear regression. Kirby Bauer disk diffusion method was used to determine the inhibition zone diameters of six tested strains and the MIC and MBC were compared to study their antibacterial activity. 23% C2H5OH-17%(NH4)2SO4 aqueous two-phase extraction system was best to extract FFO, the variance of response surface analysis showed that the pH and mass fraction of NaCl effect on the extraction rate was significant. The best extraction conditions: crude extract mass fraction was 19.35%, pH7.76, mass fraction of NaCl was 2.38 g/mL, the maximum extraction rate was 96.68%(P=0.994). The inhibitory effect on Bacillus subtilis of FFO was strongest, the inhibitory rate was 98.57% in high dose with MIC for 1.56 mg/mL, the secondary was Salmonella, Staphylococcus aureus and Escherichia coli, and the weakest was Penicillium and Aspergillus niger.