Optimization of Extraction and Purification Process of Indican from Baphi-cacanthus cusia Leaves and Its Antibacterial Activity Evaluation
In this study,indican was extracted and enriched from the leaves of Baphicacanthus cusia(Ness)Kuntze using ultrasonic low-temperature extraction and adsorption-separation technology with macroporous resin.The ultrasonic extraction process was optimized by response surface methodology based on the single-factor experiment.The optimal type was selected from six kinds of macroporous resins and the optimal adsorption-desorption process conditions of macroporous resin purification of indican were determined.Meanwhile,the high-purity indican extract was prepared.The minimum inhibitory concentration(MIC)of high-purity indican for Staphylococcus aureus and Escherichia coli was determined using 96 well plate micro method.The results showed that the optimal conditions for ultrasonic extraction process were as follows:the dried B.cusia leaf powder was 5 g,the ultrasound power was 458 W,the extraction time was 29 min,the temperature was 32℃,the solid-liquid ratio was 1∶10(g∶mL),and extracted 2 times.Under these conditions,the extraction rate of indican from B.cusia leaves was(93.15±0.26)%.The X-5 type of microporous resin had the best adsorption-desorption performance of the indican.The optimal process conditions of purification with macroporous resin were as follows:macroporous resin was 100 g,the sample volume was 500 mL,the ethanol volume fraction in the eluent was40%,and the elution volume was400 mL.Under these conditions,the recovery rate of indician was(82.97±0.30)%,and the purity increased from(18.32±0.18)%to(86.43±0.31)%.The MIC values of indican crude extract against S.aureus and E.coli both were 350 mg/L.The purified indician exhibited excellent antibacterial activity.The MIC values of high-purity indican extract against S.aureus and E.coli were 21.88 and 43.75 mg/L,respectively,which presented better antibacterial effect than the positive control gentamycin sulfate(MIC values were 43.75 and 87.50 mg/L).
Baphicacanthus cusiaindicanlow-temperature ultrasonic extractionpurification with macroporous resinantibacterial activity
万方数据
维普
