Simultaneous determination of rhynchophylline, isorhynchophylline, and their eight metabolites in rats

Abstract

A quantification method using HPLC-MS for simultaneous determination of two major bioactive alkaloid isomers [rhynchophylline (RHY) and isorhynchophylline (ISOR)] and their 8 metabolites were established. The method provided satisfactory precision, accuracy and sensitivity in quantification of these compounds in biomedia. The quantification limit was as low as 0.01ng/ml. With this method, the pharmacokinetic profiles of these compounds were investigated after oral administration of two Kampo formulations yokukansan and chotosan, and compared with those after oral administration of pure compounds. Interestingly, the contents of RHY and ISOR in rat brain after administration of extracts of yokukansan and chotosan were higher than those in rat brain after individual administration of RHY and ISOR, respectively.