title: Melatonin, melatonin isomers and stilbenes in Italian traditional grape products and their antiradical capacity.
abstract: Although polyphenols represent the paradigm of the health-promoting effects ascribed to grape products, recently, attention has been paid to dietary melatonin, significantly present in Mediterranean foods. In this work, we measured melatonin, its isomers, stilbenes (trans- and cis-resveratrol and their glucosides, piceids) and total polyphenols in some different grape products (red, white and dessert wines, grape juices and Modena balsamic vinegars) of distinct Italian areas. We also evaluated their antiradical activity by DPPH(·) and ABTS(·+) assays. For indoleamine analysis, the separation was carried out on a 1.7-μm C18 BEH column and the detection performed by means of mass spectrometry with electrospray ionization in positive ion mode with multiple reaction monitoring. The confirmation of the peak identity was accomplished by injection into the high-resolution system (Orbitrap) using accurate mass measurements (error below 1.0 ppm). Mass spectrometry analyses revealed, for the first time, the presence of melatonin in dessert wines and balsamic vinegars, as well as the occurrence of three different melatonin isomers in grape products.
authors.affiliation: Dipartimento di Scienze Agrarie ed Ambientali, Università degli Studi di Milano, Milano, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Vitalini
authors.forename: Claudio
authors.initials: C
authors.lastname: Gardana
authors.forename: Paolo
authors.initials: P
authors.lastname: Simonetti
authors.forename: Gelsomina
authors.initials: G
authors.lastname: Fico
authors.forename: Marcello
authors.initials: M
authors.lastname: Iriti
mesh_terms: D000704:Analysis of Variance; D000975:Antioxidants / Q000032:analysis* / Q000378:metabolism; D052160:Benzothiazoles; D001628:Beverages / Q000032:analysis; D001713:Biphenyl Compounds; D002851:Chromatography, High Pressure Liquid; D007536:Isomerism; D016014:Linear Models; D008550:Melatonin / Q000031:analogs & derivatives / Q000032:analysis* / Q000378:metabolism; D010851:Picrates; D021241:Spectrometry, Mass, Electrospray Ionization; D013267:Stilbenes / Q000032:analysis* / Q000378:metabolism; D013451:Sulfonic Acids; D053719:Tandem Mass Spectrometry; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D010851:Picrates; D013267:Stilbenes; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D008550:Melatonin