Identification of buckwheat phenolic compounds by reverse phase high performance liquid chromatography–electrospray ionization-time of flight-mass spectrometry (RP-HPLC–ESI-TOF-MS)

This study describes the characterization of phenolic compounds in buckwheat. Reverse phase high performance liquid chromatography (RP-HPLC) coupled to electrospray ionization-time of flight-mass spectrometry (ESI-TOF-MS) has been applied to separate and characterize thirty phenolic compounds in buckwheat flour. As far as we know, 2-hydroxy-3-O-β- d -glucopyranosil-benzoic acid, 1-O-caffeoyl-6-O-alpha-rhamnopyranosyl-β-glycopyranoside and epicatechin-3-(3″-O-methyl) gallate were tentatively identified in buckwheat for the first time. The sensitivity, mass accuracy and true isotopic pattern of the TOF-MS, legitimated the identification of phenolic compounds present in buckwheat extract. Furthermore, other “unknown” compounds were also reported in the ethanolic extracts of buckwheat.