Isolation and Identification of Puerarin

[Objective] The purpose of the study was to screen out the process route of extracting,isolating and purifying puerarin,which was suitable for industrial production.[Method] The extracted and refined puerarin was analyzed and identified by melting point method,infrared spectrophotometry,nuclear magnetic resonance hydrogen(NMR-H) spectroscopy and UV spectrophotometry.[Result] The melting point of refined puerarin was 327-328 ℃ and it was basically identical with the melting point of standard puerarin.On thin layer spectrum,both the dots of refined and standard puerarin showed blue fluorescence under UV-light lamp and both of their Rf values were 0.31.The infrared data of refined puerarin were IRUKBrMax(cm-1): 3 398,1 630,1 584,1 515,1 443,1 384,1 257,1 178,1 118,1 081 and 1 041 and that of standard puerarin was IRUKBrMax(cm-1): 3 370,1 631,1 607,1 514,1 447,1 396,1 273,1 210,1 103,1 059 and 1 008.The NMR-H data of refined puerarin accorded with literature reports.The absorbance of refined puerarin was detected at 250 nm,the puerarin content of the refined was calculated to be 97% through regression equation.The yield rate of refined puerarin of liquid-liqiud extraction was 1.41%.[Conclusion] Isolation and purification of puerarin by liquid-liqiud extraction was cheap in cost,simple to operate and could be used in industrial production.