Metabolic kinetic of puerarin in beagle liver microsomal by HPLC-ESI-MS

Objective: To develop a HPLC-ESI-MS method for the determination of puerarin and its metabolite and study the metabolic kinetics in beagle dog liver microsomes. Method: Beagle dog liver microsomes were prepared by using ultracentrifugation method. Chromatography was performed on a Shimadzu C ₁₈ column (2. 0 mm × 150 mm, 5 μn). Amethanol-water gradient system was used. ESI interface was applied in the positive, and SIM m/z 417 was puerarin and m/z 531 was daidzein. Result: The puerarin was metabolized by NADPH regenerating system in beagle dog microsomes. The Michaelis-Menten parameters K_m and V_max in beagle dog microsomes were initially estimated by analyzing Lineweave-Brurk plot. The V_max K_m of puerarin were (0. 047 ± 0. 006) mg min ^-1· g^-1, (1. 22 ± 0. 53) mg · L ^-1. Conclusion: The puerarin and daidzein can be rapidly determined by HPLC-MS in beagle dog microsomes and the puerarin was metabolized to daidzein by CY P450. The study can give help for Baige capsule.