Extraction Optimization of Active Ingredients in Huangshan Gongju and Analysis of HPLC-MS

The antioxidant activity and chemical composition of extracts from Huangshan Gongju was studied in this work. The extractive conditions with antioxidant activity as an indicator were optimized by response surface method. The conditions were as follows:60% ethanol aqueous, the ratio of liquid to material 35:1 (g/mL), ultrasonic time of 25 min. Under this conditions, the total antioxidant capacity of the extract was (2.134±0.011) mmol/L (RSD=1.97%, n=3), which was in good agreement with the predicted value (2.010 mmol/L). The antioxidative activity of extract was analyzed by FRAP method and DPPH method. The total antioxidant capacity of the extracts (total flavonoid in equivalent of rutin was 7.88 mg/L) was equivalent to the reduction power of 2.87 mmol/L ferrous ion. The DPPH free radical scavenging rate of the extracts (total flavonoid in equivalent of rutin was 25.85 mg/L) were 94.81%. The main antioxidant components of ethanolic extracts were analyzed by HPLC-MS and 114 compounds were identified including 72 flavonoids, 7 chlorogenic acid and their derivatives and 8 coumarin derivatives. These compounds probably is the material basis of the antioxidant activity of Huangshan Gongju.