Effects of Different Solvents and Extraction Methods on Extraction Percentages of Active Components from Couplet Medicines of Glycyrrhizae Radix et Rhizoma and Coptidis Rhizoma

Objective: To investigate effects of different solvents and extraction methods on yield of active ingredients from couplet medicines of acid-base compatibility. Method: With couplet medicines of Glycyrrhizae Radix et Rhizoma and Coptidis Rhizoma as the object of this research,water and 75% ethanol as extracting solvents,mixing or single reflux-boiling as extracting methods,effects of different solvents and extraction methods on yield of active ingredients from this couplet medicines were investigated. RP-HPLC was adopted to determine contents of liquiritin and glycyrrhizin,berberine hydrochloride with mobile phase of acetonitrile( A)-0. 05%phosphoric acid solution( B) for gradient elution( 0-8 min,19% A; 8-35 min,19%-50% A; 35-36 min,50%-100% A; 36-40 min,100%-19% A) and acetonitrile-0. 05 mol · L-1KH2PO4solution( 50: 50),detection wavelength at 237 and 345 nm,respectively. Result: With berberine hydrochloride as index,extracting rate was in the order of mixing ethanol reflux( 100. 0%) ethanol reflux alone( 98. 2%) decoction alone( 80. 3%) mixing decoction( 54.6%); Extracting percentages of glycyrrhizin were sorted as following: mixing ethanol reflux( 100. 7%) decoction alone( 99. 8%) ethanol reflux alone( 97. 8%) mixing decoction( 69. 0%); Yield of liquiritin was in the order of mixing ethanol reflux( 98.5%) ethanol reflux alone( 93. 6%) decoction alone( 91. 3%) mixing decoction( 66.9%). After mixing alcohol extract were taken vacuum recovery,there was a lot of precipitate,it was washed by water,transfer rates of liquiritin,glycyrrhizin and berberine hydrochloride were more than 88%. Conclusion: Solvents and extraction methods had significant influence on yield of active ingredients from couplet medicines of Glycyrrhizae Radix et Rhizoma and Coptidis Rhizoma,this study showed that prescription containing couplet medicines of acid-base compatibility extracted separately in clinical decoction applocation,but it should be extracted by ethanol in industrial production.