title: HPLC-MSn analysis of phenolic compounds and purine alkaloids in green and black tea.
abstract: Tea is a complex mixture containing a range of compounds from simple phenolics to complex thearubigins, many of which have well-recognized antioxidant properties. This paper describes the application of high-performance liquid chromatography-mass spectrometry (HPLC-MS(n)) methods for the rapid and routine analysis of more than 30 phenolics in tea. Green and black tea infusions were injected directly onto a reversed phase HPLC column, and the phenolics eluted using two different mobile phase gradients, one optimized to resolve catechin derivatives and the other, flavonols and theaflavins. Compounds, identified on the basis of their retention time, absorbance spectrum, and MS fragmentation pattern, included (+)-catechin, (-)-epicatechin, theaflavin and their various gallate derivatives, quercetin and kaempferol mono-, di-, and triglycosides, quinic acid esters of gallic acid and hydroxycinnamates, and the purine alkaloids, caffeine and theobromine.
authors.affiliation: Plant Products and Human Nutrition Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, United Kingdom.
authors.forename: Daniele
authors.initials: D
authors.lastname: Del Rio
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Stewart
authors.forename: William
authors.initials: W
authors.lastname: Mullen
authors.forename: Jennifer
authors.initials: J
authors.lastname: Burns
authors.forename: Michael E J
authors.initials: ME
authors.lastname: Lean
authors.forename: Furio
authors.initials: F
authors.lastname: Brighenti
authors.forename: Alan
authors.initials: A
authors.lastname: Crozier
mesh_terms: D044946:Biflavonoids / Q000032:analysis; D002110:Caffeine / Q000032:analysis; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D044948:Flavonols / Q000032:analysis; D013058:Mass Spectrometry; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D011687:Purines / Q000032:analysis*; D013805:Theobromine / Q000032:analysis
chemical_list: D044946:Biflavonoids; D044948:Flavonols; D010636:Phenols; D010936:Plant Extracts; D011687:Purines; C056068:theaflavin; D002110:Caffeine; D002392:Catechin; D013805:Theobromine