The suitability of the model equation for predicting the optimum response values was tested by executing three experiments under five different conditions. The experimental yield of flavonoids from the leaves of C. paliurus was close to the predicted yield (Supplementary Table 1S). There was not statistically different at 3% level of significance between the experimental and predicted values. The results indicated that the experimental values were in good agreement with the predicted ones, and the regression model was accurate and adequate for the extraction process.