Optimization of nanofiltration concentration process of Sophora flavescens extract by coupling technology of response surface methodology and regulating Donnan effect / 中草药

ABSTRACT

Objective: Response surface analysis and regulating Donnan effect methodology were used to optimize the matrine concentration by nanofiltration techonology. Methods: On the basis of single factor experiment results, molecular weight cut-off (MWCO) of nanofiltration membrane, concentration and pH were selected as influencing factors to evaluate the retention rate of matrine and total alkaloids with Box-Behnken central composite experiment design, and then, the optimal concentration parameters were calculated in the conditions of pH 6-7 to regulate Donnan effect between alkaloids and nanofiltration membrane. Results: The retention rate of matrine was of positive relevance with the ethanol concentration. The optimal concentration parameters were as follows: cutting off molecular weight of 150, pH of 6.19, concentration of 204.3 μg/mL, ethanol concentration of 15%, the retention rate of matrine and total alkaloids were 94.41% and 97.63%, respectively. Conclusion: The combination of ethanol regulation Donnan effect and response surface analysis can well optimize the concentration process of S. flavescens extract by nanofiltration, and the results provide the references for nanofiltration concentration for heat-sensitive Chinese materia medicia.