Table 4 shows the experimental conditions of theBBDalong with
the corresponding values observed for the four responses studied.
Experimental data was fitted to the quadratic model by ANOVA.
The ANOVA for the four responses is shown in Table 7. The analysis
showed that all of the four models were significant at 95% confidence
and the lack of fit was not significant. It showed that the
fitted four models were considered adequate. The calculated coefficients
of all factors are shown in Table 7. The fitted models in
terms of coded factors were presented in Eqs. (5)–(8). Coefficient
of determination (R2) for extraction yield of tetrahydropalmatine,
imperatorin, isoimperatorin and yield of extracta sicca was 0.9508,