Screening of bioactive components from traditional Chinese medicine by immobilized β2 adrenergic receptor coupled with high performance liquid chromatography/mass spectrometry

Traditional Chinese medicine (TCM) represents a valuable resource for lead compounds discovery. Given the complexity of TCM components, analytical methods play a key role in novel drug development. In our study, we established a high specific and reliable bio-active components screen system, where beta(2) adrenergic receptor (beta(2)-AR) was immobilized on silica by non-covalent bonds and packed into a stainless steel column (4.6 x 50 mm, 7 mu m) to form beta(2)-AR chromatography column. The column was further coupled with high performance liquid chromatography-time of flight tandem mass spectrometry (TOF-MS/MS). By utilizing this strategy, we successfully identified four beta(2)-AR-targeting compounds: tetrahydroberberine, tetrahydrocolumbamine, fumarine and corydaline from Corydalis Rhizome. The association constants between beta(2)-AR and tetrahydroberberine (9.04 x 10(4)/M) as well as fumarine (4.30 x 10(4)/M) were determined by frontal chromatography. We also found that these two compounds shared the identical binding site on immobilized beta(2)-AR with corresponding concentrations of 6.67 x 10(-4 )M and 5.88 x 10(-4) M, respectively. The newly established method represents an efficient tool to identify the target specific natural compounds.