Determination of the Predominant Catechins in Acacia catechu by Liquid Chromatography/Electrospray Ionization-Mass Spectrometry

摘要

A high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (LC/ESI-MS)method under selected ion monitoring mode (SIM)was developed to quantitate the predominant catechins,catechin,epicatechin,epicatechin-3-O-gallate,and epigallocatechin-3-O-gallate,in the medicinal plant catechu (Acacia catechu).Other major secondary products including caffeine,flavanol dimers,and flavonol glycosides were also identified by their molecular ion peaks and fragmentation peaks using LC/MS and LC/MS/MS.For the investigated ion concentration ranges of catechin,epicatechin,epicatechin-3-O-gallate,and epigallocatechin-3-O-gallate,good linearities (r~2 > 0.99)were obtained for each calibration curve.Validation for this method showed an accuracy ranging from 1.06 to 11.76%,and the precision (relative standard deviation)varied between 1.60 and 9.36% for these four analytes.This is the first quantitative determination of all predominant catechins in catechu heartwood and leaves.