Content Determination of Flavonoid in Whole Plants of Houttuynia cordata

Taking the whole plant of Houttuynia cordata Thunb.as the raw material,ethanol as solvent extraction,Soxhlet extraction method was used to extract flavonoid.The elements such as extraction temperature,ethanol concentration,extraction time,solid-liquid ratio which affected the yield of flavonoid from whole plants of H.cordata were investigated by orthogonal experiment.Content of flavonoid was determined by Al(NO3)3 colorimetry.The results showed that absorption had good linear relationship with rutin concentration at the range of 48.75~377.31μg/mL(R2=0.999 4).RSD was 0.21%,indicating good repetitiveness.The average recovery rate was 99.10%,it showed that the method was stable and reliable.The optimal conditions were as follows: extraction temperature at 100℃,ethanol concentration of 80%,extraction time 3 h,solid-liquid ratio 1∶30.The yield was 12.59% under these conditions.