Anti-Oxidative Constituents of Ethanol Extract from Buckwheat Seeds by HPLC-Electro-Spray MS

The study investigates major anti-oxidative constituents of ethanol extracts from the seeds of common buckwheat and tartary buckwheat. Ethanol extracts from buckwheat seeds were arranged to react with 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. HPLC was used to identify anti-oxidative constituents of the ethanol extracts, and electro-spray MS was used to characterize the structures of these identified anti-oxidative constituents to confirm them. The ethanol extracts of common buckwheat and tartary buckwheat seeds both had DPPH free radical-scavenging effect; HPLC analysis showed that the ethanol extracts of both common buckwheat and tartary buckwheat seeds presented two main anti-oxidation peaks, which correspondingly had same chromatographic retention times and spectral information; electro-spray MS analysis showed that the molecular weights and MS fragmentation patterns of the anti-oxidative constituents in the ethanol extracts from buckwheat seeds were the same as those of rutin and quercetin in the control samples. HPLC-MS/MS was capable of being used to rapidly identify anti-oxidative constituents in the extract of buckwheat seeds, and the main anti-oxidative constituents of buckwheat seed extract were mainly rutin and quercetin, and the anti-oxidative activity of quercetin was higher than that of rutin.