Response Surface Optimization for Ultrasonic Ethanol-alkali Extraction of Total Phenols of Magnolia officinalisvar.biloba

【Objective】 Optimize the extraction condition of highest yields of total phenols(magnolol,honokiol) for cortex Magnolia officinalis var.biloba,using the response surface analysis.【Method】 The extraction factors of the concentration of ethanol,concentration of alkali,solid-to-liquid and periods of ultrasound-assisted extraction were employed.【Results】 The second-order quadratic regression equation fitted the experimental data well with regard to magnolol(R2=0.940 2),honokiol(R2=0.962 6) and total phenols(R2=0.960 6),respectively.Under the condition of ultrasonic power 150 W,the optimum extraction conditions for total phenols were ethanol 56%,alkali 0.8%,solid-to-liquid 1∶36,period of extraction 29 min,where herein yields of magnolol were 1.95 mg/g,honokiol were 9.80 mg/g,total phenols were 11.75 mg/g.【Conclusion】 The predicted values got consistent with experimental values.Ethanol-alkali extraction of total phenols dominated in time,power and efficiency,comparing with ethanol and alkali extraction.