CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
artículos
Título:
Melatonin levels, determined by LC-ESI-MS/MS, deeply fluctuate during the day in Vitis vinifera cv Malbec. Evidences of its antioxidant role in fruits.
Autor/es:
BOCCALANDRO, H.E.; GONZALEZ, C.V.; WUNDERLIN, D.A.; SILVA, M.F.
Revista:
JOURNAL OF PINEAL RESEARCH
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2011 vol. 51 p. 226 - 232
ISSN:
0742-3098
Resumen:
The identification of melatonin (MT) in plants inspires new investigations to understand its biological function and which endogenous and external factors control its abundance in these organisms. Due to therapeutical and nutraceutic properties of MT, it is also important to develop reliable analytical methods for its quantification in vegetal matrices containing this indoleamine, such as grape and wine. The main objectives of the present study were: to study if MT levels fluctuate during the day in berry skins of Vitis vinifera L. cv Malbec, connecting its abundance to its putative antioxidant function, to determine whether daylight reaching clusters negatively controls melatonin levels, and to evaluate whether total polyphenols and anthocyanins accompanied melatonin fluctuation at harvest with the purpose to find a moment of the day where high levels of these valuable components of wine co-exist in grapes. The presence of melatonin in grape was evaluated by high-performance liquid chromatography/ electrospray ionization tandem mass spectrometry. It has been demonstrated for the first time that MT levels fluctuate during the day for plants growing under natural conditions in a fruit organ and in the specie of Vitis vinifera. We also detected that the diurnal decay of melatonin concentration in berry skins as induced by sunlight, because covered bunches retained higher MT levels than exposed ones, thus explaining at least part of the bases of its daily fluctuation. Evidences of melatonin antioxidant role in grapes have also been proven by monitoring malondialdehyde during the day