Abstract

^{Callicarpa nudiflora Hook. Et Arn. is one of the most important medicinal plants, but no information is available on optimal extraction of its total flavonoids. Effects of four single-factor treatments on total flavonoids during extraction of C. nudiflora and optimization of extraction condition, namely time, ethanol concentration, liquid-solid ratio, and temperature on the extracting rate of total flavonoids of C. nudiflora were studied in this paper. The optimization processes were conducted using response surface methodology. The results showed that the optimal conditions by central composite experimental design for extracting rate of total flavonoids was at a temperature of 90°C, liquid-solid ratio 41:1, ethanol concentration 73%, and time 3.6 h. Under these conditions, the maximal observed extracting rate (5.378%) of total flavonoids of leaves was obtained. Analysis of variance for quadratic polynomial regression model indicated that the model was extremely significant (P<0.0001) and the determination coefficient (R2) was 0.9613, which implied that the model of extraction technology is simple, reliable and highly efficient. At the same time, it can forecast the changes of extracting rate of total flavonoids during the extraction, and provide theoretical basis for practical production.}

^{Key words: Callicarpa nudiflora Hook. Et Arn., total flavonoids, response surface methodology, extraction.}