[Investigation on the marker substances of crude drugs in formulations. II. Marker substances for the identification of Cistanchis Herba in drinkable preparations].

There are few reports about marker substances for the identification of Cistanchis Herba in formulations. First, constituent analysis was performed by HPLC for screening of a marker substance, using several lots of Cistanchis Herba and its fluid extract. As a result, two components were clearly detected, which were thought to be good marker substances and identified to be echinacoside and acteoside by structural analysis. Stability testing of these two marker substances in various pH and temperature conditions was carried out, which suggested that they are stable and suitable enough for the identification. Therefore, the identification methods of Cistanchis Herba and its fluid extract in formulations were investigated using five different kinds of commercial drinkable preparations with authentic standard of echinacoside and acteoside as marker substances. Consequently, echinacoside and acteoside were clearly detected in all formulations investigated, using an HPLC-photodiode array detector system. Echinacoside and acteoside will be successfully used as marker substances for the identification of Cistanchis Herba and its fluid extract in formulations.