Extracting Total Flavonoids from Gynostemma pentaphyllum with Decompressing Inner Ebullition

Using Gynostemma pentaphyllum(Thunb.) Makino as raw material, the extraction of total flavonoids from Gynostemma pentaphyllum were studied.Using the decompressing inner ebullition,Gynostemma pentaphyllum powder was desorbed and extracted to investigate the effects of factors on the extraction rate. The best desorption and extraction conditions were found out and compared with traditional extraction method. The optimal desorption conditions were the desorption solvent of80% ethanol, desorption time of 25 min, 10 mL of solvent, extraction pressure of 0.025 MPa, extraction temperature of 50 ℃,using water as extraction solvent, 25 times to raw material,extracted twice for 20 min each time.Under these conditions, the extraction rate of flavonoids could reach up to 1.02%. Compared with the traditional ethanol extraction method, the yield of total flavonoids was increased by 0.20%, the extraction time was shorter,the amount of ethanol was 7 times less with an obvious advantage.