LC/MS/MS determination and pharmacokinetic studies of six compounds in rat plasma following oral administration of the single and combined extracts of Eucommia ulmoides and Dipsacus asperoides

AIM:To establish and apply a new LC/MS/MS method for the simultaneous,quantitative determination of six ingredients,aucubin(AU),geniposide(GP),geniposidic acid(GPA),pinoresinol diglucoside(PDG),secologanin(SLG),and loganin(LG) in single and combined extracts of Eucommia ulmoides and Dipsacus asperoides.METHOD:Using the LC/MS/MS-ESI-MRM mode to detect the six compounds,chromatographic separation was achieved on an Agilent Eclipse plus C18 column,and the mobile phase consisted of solvent A(CH3CN) and solvent B(H2O containing 0.01% CH3COOH V/V).RESULTS:This method was successfully applied to quantify the six compounds in rat plasma after oral administration,and showed good precision,accuracy,reproducibility,and linear regression(r20.99).CONCLUSION:The results showed that following the use of the two medicinal plants,for AU and GP,the values of tmax markedly increased,and the values of cmax markedly decreased.It was found that the compatibility of the medicinal plants might affect their pharmacokinetic properties of their constituents.