Optimization of Ultrasonic-Assisted Extraction of Daurisoline and Dauricine from Menispermi Rhizoma by Response Surface Methodology

Two main alkaloid compounds in the root of Menispermum dauricum DC were analyzed by ultra-performance liquid chromatography with a photodiode array detector and fast quadrupole mass detector. The optimal extraction conditions were determined by response surface methodology and the experimental factors were determined using a Box-Behnken design. The model adequacy of this design for daurisoline and dauricine was verified by one-way analysis of variance. The adjusted regression coefficients for daurisoline and dauricine were 0.9227 and 0.9426, respectively, and the lack-of-fit values for the two alkaloids were 0.418 and 0.119, respectively. The models for daurisoline and dauricine were considered adequate, because the R-2 values were close to 1 and the lack-of-fit values were nonsignificant (p>0.05). Optimal extraction conditions for daurisoline and dauricine were predicted to be 69 degrees C for 36min in 100% methanol, with maximum yields of 6.533 and 1.045mg/g, respectively. Under these conditions, the actual yields of daurisoline and dauricine were 6.724 +/- 0.140 and 1.048 +/- 0.025mg/g, respectively.