The Pharmacokinetics of Magnolol and Honokiol in Rats by LC-MS/MS

A rapid,sensitive and selective method for the simultaneous determination of magnolol and honokiol in plasma was described by liquid chromatography-tandem mass spectrometry(LC-MS/MS).Magnolol and honokiol were separated on Waters XTerra C18 column using V(acetonitrile)∶V(0.1 mmol/L ammonium acetate)=75∶25 as mobile phase by isocratic elution.The flow rate was 0.2 mL/min,and injection volume was 5 μL.Determination was carried out by negative ion electrospray ionization mode with selected reaction monitoring.The assay was linear from 1 to 1 000 μg/L,and the lower limit of quantification(LLOQ) was 1 μg/L.The limit of quantitation(S/N=3) was 0.1 μg/L.Intra-day and inter-day precision were less than 15%.The relative deviations were in the range of 3.4%—6.6% for magnolol and 0.5%—4% for honokiol,respectively.The recoveries of magnolol and honokiol were more than 90%.The assay was applied to the pharmaco knietic study of magnolol and honokiol after intragastric administration of Banxia-Houpu Decoction to rats.