title: Isolation of hydroxycinnamoyltartaric acids from grape pomace by high-speed counter-current chromatography.
abstract: A method for the isolation of caftaric, coutaric and fertaric acids from grape pomace by high-speed counter-current chromatography (HSCCC) was developed. Using a system of hexane/ethyl acetate/methanol/water 3:7:3:7 (v/v/v/v) and 0.5% trifluoroacetic acid (TFA) in the head-to-tail elution mode, the target compounds were separated from co-extracted polyphenolics and subsequently isolated in a second run (tert-butyl-methyl ether/acetonitrile/n-butanol/water, 2:2:1:5 (v/v/v/v) and 0.5% TFA; tail-to-head elution mode). The concomitant flavonoid quercetin 3-glucuronide was also isolated with the present method. The compounds were characterized by 1H NMR spectroscopy, by LC/electrospray ionization (ESI)-MS/MS in the negative ionization mode, and by UV spectroscopy. A purity of 97.0% (2.0% Z-isomer) for caftaric acid, 97.2% (4.8% Z-isomer) for coutaric acid, and 90.4% (13% Z-isomer) for fertaric acid was obtained from 10 g of grape pomace with yields of 62, 48 and 23%, respectively. Caftaric and coutaric acids may be used for in vitro and in vivo studies and as reference substances for analytical purposes.
authors.affiliation: Institute of Food Technology, Section Plant Foodstuff Technology, Hohenheim University, August-von-Hartmann-Strasse 3, D-70599 Stuttgart, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Maier
authors.forename: Solveigh
authors.initials: S
authors.lastname: Sanzenbacher
authors.forename: Dietmar R
authors.initials: DR
authors.lastname: Kammerer
authors.forename: Nicolai
authors.initials: N
authors.lastname: Berardini
authors.forename: Jürgen
authors.initials: J
authors.lastname: Conrad
authors.forename: Uwe
authors.initials: U
authors.lastname: Beifuss
authors.forename: Reinhold
authors.initials: R
authors.lastname: Carle
authors.forename: Andreas
authors.initials: A
authors.lastname: Schieber
mesh_terms: D003377:Countercurrent Distribution / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification*; D011794:Quercetin / Q000031:analogs & derivatives / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D027843:Vitis / Q000737:chemistry*
chemical_list: D010636:Phenols; D012997:Solvents; C515102:coutaric acid; C515103:fertaric acid; D011794:Quercetin; C515101:caftaric acid