Characterisation of flavonoids in Orostachys japonicus A. Berger using HPLC-MS/MS: Contribution to the overall antioxidant effect

Orostachys japonicus cultivated in the Republic of Korea was analysed for flavonoid content via HPLC coupled to MS/MS. Amongst 16 compounds that were characterised, eight fiavonoids and one alkaloid were characterised for the first time: two procyanidin dimer gallate isomers (1 and 2), epigallochatechin-3-gallate (3), two procyanidin dimer digallate isomers (4 and 9), quercetin 3-0-rhamnosy1-7-0-glucoside (6), myricetin 3-O-glucoside (10), kaempferol (16) and N-1,N-5,N-10-tri-p-(E,E,E)-coumaroylspermidine (15). The identified compounds were quantified by HPLC-UV/DAD. The antioxidant activity of the O. japonicus flavonoids was determined via 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.), 2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulphonic acid) radical cation (ABTS(.+)) and nitric oxide radical (NO.) scavenging assays. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.