title: Mass spectrometry of 1,3- and 1,5-dicaffeoylquinic acids.
abstract: Samples of 1,3- (1) and 1,5-dicaffeoylquinic acid (2) and their hexaacetate derivatives were examined using positive and negative electrospray ionization mass spectrometry and tandem mass spectrometry. Differences in the various spectra allow the discrimination of each of the isomers. Specific losses in the spectra of 2 also permit the identification of the site of substitution of one of the caffeic acid moieties as being at the 5-position. The spectra of 3,5- (3) and 4,5-dicaffeoylquinic (4) acids and their hexaacetate derivatives were compared with those of 1 and 2 and their derivatives, and differences in ion abundances or the presence/absence of specific ions can be used to identify uniquely each of the compounds.
authors.affiliation: Department of Pharmacology/Toxicology, Division of Medicinal and Natural Products Chemistry, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, USA. Schram@pharmacy.arizona.edu
authors.forename: Karl
authors.initials: K
authors.lastname: Schram
authors.forename: Petra
authors.initials: P
authors.lastname: Miketova
authors.forename: Jiri
authors.initials: J
authors.lastname: Slanina
authors.forename: Otakar
authors.initials: O
authors.lastname: Humpa
authors.forename: Eva
authors.initials: E
authors.lastname: Taborska
mesh_terms: D002934:Cinnamates / Q000032:analysis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods*; D008968:Molecular Conformation; D011801:Quinic Acid / Q000031:analogs & derivatives / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: C487840:1,3-dicaffeoylquinic acid; D002934:Cinnamates; D011801:Quinic Acid; C100257:cynarine