353 Phytochem. Anal. 2009, 20, 353–364 Copyright © 2009 John Wiley & Sons, Ltd. Research Article (www.interscience.wiley.com) DOI 10.1002/pca.1133 NMR and UPLC-qTOF-MS/MS Characterisation of Novel Phenylethanol Derivatives of Phenylpropanoid Glucosides from the Leaves of Strawberry (Fragaria ¥ ananassa cv. Jonsok) Kati Hanhineva, a * † Pasi Soininen, a Mikko J. Anttonen, a Harri Kokko, a Ilana Rogachev, b Asaph Aharoni, b Reino Laatikainen a and Sirpa Kärenlampi a ABSTRACT: Introduction – Strawberry (Fragaria ¥ ananassa) is rich in polyphenols, particularly anthocyanins, lavonols, condensed tan- nins and ellagic tannins. In addition to the fruits, the leaves of strawberry also contain a wide range of phenolic compound classes, but have not been investigated to the same extent as the fruit. Objective – To characterise a metabolite group present in the leaves of strawberry, that was not amenable for identiication based on earlier information available in the literature. Methodology – Methanolic extracts of strawberry leaves were analysed by UPLC-qTOF-MS/MS and iterative quantum mechanical NMR spectral analysis. Results – The structures of phenylethanol derivatives of phenylpropanoid glucosides Eutigoside A (F4) and its two isomeric forms 2-(4-hydroxyphenyl)ethyl-[6-O-(Z)-coumaroyl]-b-D-glucopyranoside (F6) and 4-(2-hydroxyethyl)phenyl-[6-O-(E)- coumaroyl]-b-D-glucopyranoside (F1) were resolved by NMR and UPLC-qTOF-MS/MS. In addition, two other derivatives of phenylpropanoid glucosides similar to Eutigoside A but possessing diferent phenolic acid moieties, namely Grayanoside A (F5) and 2-(4-hydroxyphenyl)ethyl-[6-O-(E)-cafeoyl]-b-D-glucopyranoside (F14), were similarly identiied. Also, accurate characteristic coupling constants for the subunits are reported and their usefulness in structural analysis is highlighted. Conclusion – Chemical analysis of the leaves of strawberry (Fragaria ¥ ananassa cv. Jonsok) resulted in the identiication of a compound class, phenylethanol derivatives of phenylpropanoid glycosides, not previously found in strawberry. Copyright © 2009 John Wiley & Sons, Ltd. Keywords: strawberry; Fragaria; phenylpropanoid glucoside; natural product; UPLC-MS; NMR; phenolic compounds; natural products; genetically modiied; bioactive compounds; phenylethanol * Correspondence to: Kati Hanhineva, Department of Biosciences, University of Kuopio, P.O.Box 1627, Kuopio 70211, Finland. E-mail: kati.hanhineva@uku.i a Department of Biosciences, University of Kuopio, PO Box 1627, Kuopio 70211, Finland b Department of Plant Sciences, Weizmann Institute of Science, PO Box 26, Rehovot 76100, Israel † Present address: Department of Clinical Nutrition/Food and Health Research Centre, University of Kuopio, PO Box 1627, 7021 Kuopio, Finland Contract/grant sponsor: Finnish Cultural Foundation of Northern Savo. Contract/grant sponsor: The Tiura Agricultural Foundation. Contract/grant sponsor: Wihuri Foundation. Contract/grant sponsor: Adolpho and Evelyn Blum Career Development Chair of Cancer Research. Contract/grant sponsor: William Z. and Eda Bess Novick New Scientists Fund. Contract/grant sponsor: Israel Ministry of Science; Contract/grant number: IMOS project #3-2552. Contract/grant sponsor: Henry S. and Anne Reich Family Foundation. Introduction Fruits such as strawberry, raspberry, apple and plum that belong to the subfamily Rosoideae of the Rosaceae family are known to have exceptionally rich secondary metabolite composition (Hannum, 2004; Puupponen-Pimiä et al., 2005; Koponen et al., 2007). In particular, the phenolic compounds including phenolic acids, anthocyanins, lavonols, condensed tannins and ellagitan- nins have been widely studied and various beneicial efects on human health when consumed as part of the daily diet have been reported (Hannum, 2004). In strawberry, the phenolic composition of fruits (Aharoni et al., 2002; Määttä-Riihinen et al., 2004; Aaby et al., 2007) and leaves (Hukkanen et al., 2007), as well as lowers (Hanhineva et al., 2008), has been reported. Phenylpropanoid glucosides with additional derivatisation by phenylethanol side chain are a class of phenolic compounds that have not yet gained any great attention among researchers, and are thus not a precisely characterised metabolite group. Their role in plant metabolism has not been speciied in detail and the enzymes that catalyse the synthesis of these compounds have not been disclosed. Phenylethanol derivatised phenylpro- panoid glucosides have been identiied in plant species such as Akebia trifoliata (Gao and Wang, 2006), Eurya tigang (Khan et al., Received: 13 November 2008, Revised: 18 March 2009, Accepted: 20 March 2009 Published online in Wiley Interscience: 8 May 2009