title: Optimization, in-house validation, and application of a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for the quantification of selected polyphenolic compounds in leaves of grapevine (Vitis vinifera L.).
abstract: Polyphenols in grapevine can be constitutive or induced, depending upon cultivar, plant organ, and environmental influences. The aim of the presented work was to develop and optimize a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to study the pattern and amount of selected polyphenols in leaves of  Vitis vinifera  L. The method is simple and does not require any sample cleanup. It covers representative metabolites of the structure classes cinnamic acids, flavonoids, and stilbenes and enables the simultaneous separation and quantification of 13 polyphenols within 9 min at concentration levels between 0.1 and 3 μg/g. We present the method performance characteristics and its application to the quantification of polyphenols in grapevine leaves of the cultivars Riesling and Pinot noir. A total of 7 of 13 target polyphenols were detected at concentrations above the limits of quantification. Interestingly, instead of the expected trans-resveratrol, the investigated leaf samples of both cultivars contained cis-resveratrol-3-O-glucoside. The measurements also showed that Riesling leaves tended to contain higher concentrations of the selected polyphenols than Pinot noir. In view of its intended future use, the developed method has been shown to be a powerful and fast tool to study polyphenols in grapevine leaves subjected to environmental stress conditions.
authors.affiliation: Division of Viticulture and Pomology, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, A-3430 Tulln, Austria.
authors.forename: Katharina
authors.initials: K
authors.lastname: Schoedl
authors.forename: Astrid
authors.initials: A
authors.lastname: Forneck
authors.forename: Michael
authors.initials: M
authors.lastname: Sulyok
authors.forename: Rainer
authors.initials: R
authors.lastname: Schuhmacher
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D002934:Cinnamates / Q000032:analysis; D005419:Flavonoids / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis*; D013045:Species Specificity; D013267:Stilbenes / Q000032:analysis; D053719:Tandem Mass Spectrometry / Q000379:methods*; D027843:Vitis / Q000737:chemistry*
chemical_list: D002934:Cinnamates; D005419:Flavonoids; D059808:Polyphenols; D013267:Stilbenes