title: Identification of isomeric dicaffeoylquinic acids from Eleutherococcus senticosus using HPLC-ESI/TOF/MS and 1H-NMR methods.
abstract: Liquid chromatography-electrospray time-of-flight mass spectrometry (HPLC-ESI/TOF/MS) and a novel NMR technique, developed to maximise the sensitivity obtained from the standard NMR spectrometer, have been applied to the identification of the phenolic constituents of Eleutherococcus senticosus. In addition, molecular modelling and dihedral bond angle calculations based on the vicinal 3JHH-coupling constants have been used in the unambiguous assignment of signals in the 1H-NMR spectra. 5'-O-Caffeoylquinic acid and three isomeric compounds, 1',5'-O-dicaffeoylquinic acid, 3',5'-O-dicaffeoylquinic acid and 4',5'-O-dicaffeoylquinic acid, have been isolated and identified from a sample. The isolation and structure determination of the latter two compounds are reported for the first time from this plant.
authors.affiliation: Department of Chemistry, University of Oulu, PO Box 3000, 90014 Oulu, Finland. ari.tolonen@oulu.fi
authors.forename: Ari
authors.initials: A
authors.lastname: Tolonen
authors.forename: Topi
authors.initials: T
authors.lastname: Joutsamo
authors.forename: Sampo
authors.initials: S
authors.lastname: Mattlla
authors.forename: Terttu
authors.initials: T
authors.lastname: Kämäräinen
authors.forename: Jorma
authors.initials: J
authors.lastname: Jalonen
mesh_terms: D000465:Algorithms; D002109:Caffeic Acids / Q000737:chemistry* / Q000302:isolation & purification; D002726:Chlorogenic Acid / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002934:Cinnamates / Q000737:chemistry / Q000302:isolation & purification; D028001:Eleutherococcus / Q000737:chemistry*; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D011522:Protons; D011801:Quinic Acid / Q000031:analogs & derivatives / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D002109:Caffeic Acids; D002726:Chlorogenic Acid; D002934:Cinnamates; D010936:Plant Extracts; D011522:Protons; D011801:Quinic Acid; C473201:4',5'-O-dicaffeoylquinic acid; C100257:cynarine; C100434:3,5-dicaffeoylquinic acid; C473200:5-caffeoylquinic acid