Simultaneous and highly sensitive quantification of five bioactive components in Fructus Psoraleae and in rat plasma by HPLC with fluorescence detection

Psoralea corylifolia L. is an important medicinal herb that produces biologically active components. A simple and sensitive high performance liquid chromatography with fluorescence (HPLC-FL) method has been developed for the simultaneous quantification of five bioactive compounds including psoralen, isopsoralen, bavachin, bavachinin and bakuchiol in Fructus Psoraleae. The chromatographic separation was carried out on a C18 column with gradient elution. The fluorescence properties of these five compounds were investigated. At the optimum detection wavelength (λex/λem = 280/405 nm), the analytes provided good fluorescence signals, and simultaneous and highly sensitive determination of these five components was achieved. The limits of detection (signal to noise ratio at 3) of five analytes were 0.8 ng mL−1 for psoralen, 2.5 ng mL−1 for isopsoralen, 1.2 ng mL−1 for bavachin, 2.1 ng mL−1 for bavachinin and 2.4 ng mL−1 for bakuchiol, which were lower than those for most of the current methods. Recoveries for all studied compounds in Fructus Psoraleae were between 93.7% and 108.2%. The proposed method was further applied to the analysis of rat plasma samples after oral administration of Fructus Psoraleae extraction. The results show that the developed HPLC-FL method is a very useful tool for the quality control of herbal medicine Psoralea corylifolia L., and for pharmacokinetics studies.