Chromatographic separation and identification of naturally occurring chlorogenic acids by 1H nuclear magnetic resonance spectroscopy and mass spectrometry.

The high-performance liquid chromatographic separation and identification of the phenolic compounds in extracts from coffee bean are described. The system consists of Fine SIL C18-5 analytical and preparative columns and gradient elution (solvent A, 10 mM H3PO4; solvent B, methanol). The seven chlorogenic acids isolated were identified by mass spectrometry and nuclear magnetic resonance spectroscopy. The isolated and identified compounds are 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid and 3-O-feruloylquinic acid.