NMR and UPLC-qTOF-MS/MS characterisation of novel phenylethanol derivatives of phenylpropanoid glucosides from the leaves of strawberry (Fragaria x ananassa cv Jonsok).

: Hanhineva K, Soininen P, Anttonen MJ, Kokko H, Rogachev I, Aharoni A, Laatikainen R, Kärenlampi S

: 2009

: Phytochemical Analysis

: Phytochemical analysis : PCA

: Phytochem Anal

: 20

: 5

: 353

: 64

: 12

: 0958-0344

: 1099-1565

DOI: https://doi.org/10.1002/pca.1133

Strawberry (Fragaria x ananassa) is rich in polyphenols, particularly anthocyanins, flavonols, condensed tannins 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.\nTo characterise a metabolite group present in the leaves of strawberry, that was not amenable for identification based on earlier information available in the literature.\nMethanolic extracts of strawberry leaves were analysed by UPLC-qTOF-MS/MS and iterative quantum mechanical NMR spectral analysis.\nThe structures of phenylethanol derivatives of phenylpropanoid glucosides Eutigoside A ( F4) and its two isomeric forms 2-(4-hydroxyphenyl)ethyl-[6-O-(Z)-coumaroyl]-beta-D-glucopyranoside (F6) and 4-(2-hydroxyethyl)phenyl-[6-O-(E)-coumaroyl]-beta-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 different phenolic acid moieties, namely Grayanoside A ( F5) and 2-(4-hydroxyphenyl)ethyl-[6-O-(E)-caffeoyl]-beta-D-glucopyranoside (F14), were similarly identified. Also, accurate characteristic coupling constants for the subunits are reported and their usefulness in structural analysis is highlighted.\nChemical analysis of the leaves of strawberry (Fragaria x ananassa cv. Jonsok) resulted in the identification of a compound class, phenylethanol derivatives of phenylpropanoid glycosides, not previously found in strawberry.\nINTRODUCTION\nOBJECTIVE\nMETHODOLOGY\nRESULTS\nCONCLUSION