Simultaneous determination of six major constituents in the stems of Kadsura heteroclita by LC-DAD

The stem of Kadsura heteroclita is a traditional Chinese medicine with a variety of biological activities. For efficient monitoring of the quality of the herb, a simple, rapid, and accurate HPLC method has been developed for simultaneous determination of five cyclolanostane triterpenoid compounds (schisanlactone E, nigranoic acid, schisandronic acid, and heteroclitalactones A and D) and one tetrahydrofuran lignan (d-epigalbacin) in the stems of K. heteroclita. These six compounds were separated on a C₁₈ column by elution with a mobile-phase gradient prepared from acetonitrile and 0.05% (v/v) aqueous phosphoric acid. The flow rate was 1.0 mL min^-1 and the detection wavelength was 210 nm. The recovery of the method was in the range 95.03-102.19% and a good linear relationship (r² > 0.9999) was obtained between response and compound concentration over a relatively wide range. The method was successfully applied to analysis of the herb collected at different stages of growth.