Identification of indicator components for the discrimination of Cassia plants in health teas and development of analytical method for the components.

Components that could be used as indicators for the discrimination of senna (Cassia angustifolia) from other cassia plants contained in health teas were identified, and an analytical method for the components was developed. Our results revealed two components in senna that were not found in other Cassia spp. widely used in health teas, such as C. alata, C. corymbosa, C. obtusifolia, and C. occidentalis. Structural elucidation of the two components showed that they were isorhamnetin-3-O-gentiobioside and tinnevellin glucoside. We analyzed commercial health teas using the HPLC method developed in this study. The two indicator components were detected at 366 nm using an RP C18 column and gradient elution with a mixture of water and acetonitrile (with formic acid), as the mobile phase. Our analytical method by HPLC enabled the differentiation of senna from other Cassia plants present in health teas in which sennosides A and B were detected. Moreover, this method allowed us to predict the parts of senna in health teas from the amounts of isorhamnetin-3-O-gentiobioside and tinnevellin glucoside contained in the teas.