Screening of the active compound from Tetradium ruticarpum fruits and analysis of its binding characteristics to the α1A adrenoceptor by high expression α1A adrenoceptor cell membrane chromatography

The dried fruit of the Tetradium ruticarpum (Wu Zhu Yu) tree is commonly used in traditional Chinese medicine, and its decoction can be used for treating conditions such as headaches and hypotension. In the present study, an offline two-dimensional combination method of α1A/HEK293 cell membrane chromatography (α1A/CMC) and UHPLC-MS/MS was established to screen and identify the active compound from the Tetradium ruticarpum fruits. The binding characteristics between this active compound and the α1A receptor were also analyzed by an α1A/CMC method. By this process, dehydroevodiamine was identified as the potential active compound. Equilibrium dissociation constant (Kd) values between α1A receptor and dehydroevodiamine, obtained by both stepwise frontal analysis and zonal elution analysis, were (5.18 ± 0.50) × 10-6 mol/L and (2.70 ± 0.74) × 10-6 mol/L, respectively. Our results indicate that the α1A/CMC method can not only screen active compounds from complex sample, but can also be used to calculate the binding parameters of the identified compound.