Identification of polygala oligosaccharide esters and their metabolites in rat plasma after oral administration of ethanol extract of Kai Xin San by UHPLC-MS

Using a UHPLC-TOF/MS method combined with software of Masslynx V4.1 and database in the literatures, a total of 20 polygala oligosaccharide esters (POEs) were identified in 60% ethanol extract of Kai Xin San (KXS-60%E). Furthermore, 14 POEs as well as 4 POE-metabolites were identified in rat plasma. The results revealed that POEs and POE-metabolites which were identified in rat plasma, were key components in KXS-60%E and the potential bioactive compounds for KXS action in the treatment of AD.