A combined cell membrane chromatography and online HPLC/MS method for screening compounds from Radix Caulophylli acting on the human α1A-adrenoceptor

We have developed an online analytical method that combines α1A-adrenoceptor (α1AAR) cell membrane chromatography (α1AAR-CMC) with high performance liquid chromatography and mass spectrometry (HPLC/MS) for the identification of active components from Radix Caulophylli acting on the human α1AAR. Fractions retained by the α1AAR-CMC column were captured into a loop and the components were directly analyzed by combining an 8 port column switcher with an HPLC/MS system for separation and preliminary identification. Using methoxamine as a positive control drug, magnoflorine and caulophine from Radix Caulophylli were identified as the active molecules acting on the α1AAR. This new α1AAR-CMC-online-HPLC/MS method can be applied for screening active components acting on α1AAR from traditional Chinese medicines exemplified by Radix Caulophylli. This method will be of great utility in drug discovery using natural medicinal herbs as a source of novel compounds.