Optimization of ultrasound-assisted extraction of quercitrin from Houttuynia cordata Thunb. using response surface methodology and UPLC analysis

In this study, the optimal conditions for quercitrin extraction from Houttuynia cordata Thunb. (HC) were evaluated using the response surface methodology (RSM). The quercitrin was analyzed and method validated by ultra performance liquid chromatography carried out with a photodiode array detector (UPLC-PDA). Central composite design (CCD), a type of RSM, was applied to estimate the influence of three independent variables, the extraction temperature, extraction time, and extraction concentration, on the quercitrin yield. Analysis of variance (ANOVA) showed a good model fit (r ²=0.8863). The predicted optimal quercitrin yield was 1.497% under an extraction temperature of 80°C and an extraction time of 34 min in a solvent of 95% methanol. Using these optimal conditions, the experimentally obtained quercitrin yield was 1.483% (±0.03), which agrees closely with the predicted value.