[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 C18 column (2.0 mm x 150 mm, 5 microm). 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 Km and Vmax in beagle dog microsomes were initially estimated by analyzing Lineweave-Brurk plot. The Vmax Km of puerarin were (0.047 +/- 0.006) mg x min(-1) x g(-1), (1.22 +/- 0.53) mg x 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.