title: Complex mixture analysis of organic compounds in green coffee bean extract by two-dimensional NMR spectroscopy.
abstract: A complex mixture analysis by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy was carried out for the first time for the identification and quantification of organic compounds in green coffee bean extract (GCBE). A combination of (1)H-(1)H DQF-COSY, (1)H-(13)C HSQC, and (1)H-(13)C CT-HMBC two-dimensional sequences was used, and 16 compounds were identified. In particular, three isomers of caffeoylquinic acid were identified in the complex mixture without any separation. In addition, GCBE components were quantified by the integration of carbon signals by use of a relaxation reagent and an inverse-gated decoupling method without a nuclear Overhauser effect. This NMR methodology provides detailed information about the kinds and amounts of GCBE components, and in our study, the chemical makeup of GCBE was clarified by the NMR results.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Feifei
authors.initials: F
authors.lastname: Wei
authors.forename: Kazuo
authors.initials: K
authors.lastname: Furihata
authors.forename: Fangyu
authors.initials: F
authors.lastname: Hu
authors.forename: Takuya
authors.initials: T
authors.lastname: Miyakawa
authors.forename: Masaru
authors.initials: M
authors.lastname: Tanokura
mesh_terms: D002247:Carbon Isotopes; D040503:Coffea / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D008968:Molecular Conformation; D010936:Plant Extracts / Q000032:analysis*; D011522:Protons; D011801:Quinic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D012015:Reference Standards; D013237:Stereoisomerism
chemical_list: D002247:Carbon Isotopes; D010936:Plant Extracts; D011522:Protons; C472707:caffeoylquinic acid; D011801:Quinic Acid