Mass spectrometry of 1,3- and 1,5-dicaffeoylquinic acids.
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.
Schram
Karl
K
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
Miketova
Petra
P
Slanina
Jiri
J
Humpa
Otakar
O
Taborska
Eva
E
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
C487840:1,3-dicaffeoylquinic acid; D002934:Cinnamates; D011801:Quinic Acid; C100257:cynarine