[Determination of active constituents in shi-wei (Folium Pyrrosiae) by high performance liquid chromatography]

A new analytical method for the simultaneous determination of three constituents, viz, mangiferin, isomangiferin and chlorogenic acid in Folium Pyrrosiae using high performance liquid chromatography was developed. A Zorbax-CN column (4.6 mm x 25 cm) was used; methanol--water--phosphoric acid (pH 2.5) (20:80:0.1) was used as the mobile phase. The method was rapid, sensitive, precise and showed good reproducibility. The three constituents in crude drugs were completely separated within 15 min. Recoveries of three constituents were 96.78-101.3%, with coefficients of variation 1.8-4.7%. Mangiferin and isomangiferin were separated for the first time. Pyrrosia plant materials were analyzed as follows: The powdered sample was refluxed with methanol for 4 hours, the extract was transferred into a 25 ml volumetric flask and diluted to 25 ml with methanol. A definite amount of this sample solution was injected for HPLC. The content of constituents in Folium pyrrosiae was calculated from the relevant peak height or peak area. The content of these three constituents in 7 species of Chinese Pyrrosia collected in 17 districts were determined. The results showed that these constituents varied greatly with the plant species and varied with the districts for the same species also, and should be evaluated accordingly.