Optimization of Macroporous Resin Purification Process for Bauhinia championii by Central Composite Design-Response Surface Methodology

Abstract:

Objective: To optimize purification technology of Bauhinia championii with D-101 macroporous resin. Method: HPLC was adopted to determine contents of 3', 4', 5', 5, 7-pentamethoxy flavone (flavone 1) and 3', 4'-methylenedioxy-5', 5, 6, 7-tetramethoxy flavone (flavone 2) with mobile phase of acetonitrile (A) -water (B) gradient elution (0-20 min, 30%-40%A;20-36 min, 40%-48%A) and detection wavelength of 324 nm.Taking overall desirability of desorption rates and purities of flavone 1 and flavone 2 as dependent variable, while the concentration of sample solution, ethanol concentration and volume as independent variables, multiple linear regression and binomial fitting of each level of independent variables was handled by central composite design, response surface methodology was adopted to optimize technological parameters. Result: Quadratic equation described relationship between dependent and independent variables was obviously better than multiple linear regression equation.Optimum technological parameters were as following:sample concentration 0.11 g·mL^-1, ethanol concentration 84.41%, eluent volume 13.94 BV;Average elution rates of flavone 1 and flavone 2 were 78.45% (RSD 0.32%) and 79.55% (RSD 0.33%), purities were 1.14% (RSD 0.88%) and 0.67% (RSD 1.49%). Conclusion: Optimized purification technology was feasible and stable with good predictability.