[Determination of the active ingredients in Chinese drug wuweizi (Schisandra chinensis) by TLC-densitometry].

A method of TLC densitometry was developed to determine the active ingredients (Wuweizisu A, B, C; Wuweizichun A, B; Wuweizi ester and schisanhenol) in Schisandra kernels. The samples were extracted with hexane (3 X 5 ml) for 8, 4 and 4 h respectively. The hexane extract was evaporated to dryness and then dissolved in 1 ml of methanol. Standard solutions and sample solutions were spotted on a silica gel GF254 plate, and developed with toluene-ethyl acetate (9:1) for 18 cm (for Wuweizisu A, B, C) and with toluene-ethyl acetate (4:6) for 18 cm (for Wuweizichun A, B, Wuweizi ester and schisanhenol). On examining the chromatogram under UV light the ingredients appeared as dark spots. A Shimadzu TLC model 910 was used for scanning at lambda s 260 nm and lambda R 350 nm by reflection mode. Linear calibration curves were obtained for the 7 constituents in the range of 1-5 micrograms. The average recoveries of the 7 constituents were 92.4-101.6%; the variation coefficients were 1.62-5.28%. The spots were stable for more than 24 h. This method is sufficiently simple, rapid and accurate for routine analysis.