Hindawi Publishing Corporation ISRN Spectroscopy Volume 2013, Article ID 813563, 45 pages http://dx.doi.org/10.1155/2013/813563 Review Article Recent Applications of Mass Spectrometry in the Study of Grape and Wine Polyphenols Riccardo Flamini Consiglio per la Ricerca e la Sperimentazione in Agricoltura-Centro di Ricerca per la Viticoltura (CRA-VIT), Viale XXVIII Aprile 26, 31015 Conegliano, Italy Correspondence should be addressed to Riccardo Flamini; riccardo.�amini�entecra.it Received 24 September 2012; Accepted 12 October 2012 Academic �ditors: D.-A. Guo, �. Sta�lov, and M. Valko Copyright © 2013 Riccardo Flamini. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Polyphenols are the principal compounds associated with health bene�c effects of wine consumption and in general are characterized by antioxidant activities. Mass spectrometry is shown to play a very important role in the research of polyphenols in grape and wine and for the quality control of products. e so ionization of LC/MS makes these techniques suitable to study the structures of polyphenols and anthocyanins in grape extracts and to characterize polyphenolic derivatives formed in wines and correlated to the sensorial characteristics of the product. e coupling of the several MS techniques presented here is shown to be highly effective in structural characterization of the large number of low and high molecular weight polyphenols in grape and wine and also can be highly effective in the study of grape metabolomics. 1. Principal Polyphenols of Grape and Wine During winemaking the condensed (or nonhydrolyzable) tannins are transferred to the wine and contribute strongly to Polyphenols are the principal compounds associated to the sensorial characteristic of the product. In the mouth, the health bene�c effects of wine consumption. A French epi- formation of complexes between tannins and saliva proteins demiological study performed in the end of 1970s reported confers to the wine the sensorial characteristic of astringency: that in France, despite the high consumption of foods rich bitterness and astringency of wine is linked to tannins struc- in saturated fatty acids, the incidence of mortality from ture, in particular galloylation degree (DG) and polymeriza- cardiovascular diseases was lower than that in other com- tion degree (DP) of �avan-3-ols [2, 3]. Grape tannins are used parable countries. is phenomenon was called “the French as active ingredients in medicinal products characterized paradox� and was related to the bene�cial effects of red wine by antioxidant plasma activity and for the treatment of consumption [1]. In general; polyphenols have antioxidant circulatory disorders (capillary fragility, microangiopathy of activities. eir activity as peroxyl radical scavengers and the retina, reducing of platelet aggregation, decreasing of the in the formation of complexes with metals (Cu, Fe, etc.) susceptibility of healthy cells towards toxic and carcinogenic has been shown by in vitro studies. Moreover, the ability of agents, and antioxidant activity toward human low density polyphenols to cross the intestinal wall of mammals confers lipoprotein) (see [4], and references cited herein). their biological properties. Flavonols are another important class of grape polyphe- Flavan-3-ols are one of the principal classes of grape nols. ese compounds are mainly present in the skin of polyphenols which include (+)-catechin and ( )-epicatechin, berry; the principal are quercetin, kaempferol, and myri- and their oligomers called procyanidins, proanthocyanidins, cetin present in glycoside forms such as glucoside, glu- and prodelphinidins. B-type and A-type procyanidins− and curonide, and rutin. Recently, also isorhamnetin, laricitrin, proanthocyanidins (the latter are condensed tannins) are and syringetin were identi�ed in grape [5, 6]. e structures present in the grape skin and seeds; tannins are mainly of �avonols are reported in Figure 2(b). e main biological present in seeds, and prodelphinidins are polymeric tannins activity of quercetin is to block human platelets aggregation, composed of gallocatechin units (structures in Figure 1). and it seems that it inhibits carcinogens and the cancer 2 ISRN Spectroscopy OH OH OH OH HO O H HO O H R1 OH R2 OH OH H OH OH H OH ((+) catechin) R1 = R2 = - HO O OH H (( ) epicatechin) R1 = OH R2 = − - H OH O CO OH H OH OH R2 = H R1 = O CO OH Dimer B2 gallate OH OH OH OH HO O OH H OH R1 HO O R2 OH OH O HO O OH H OH R3 R4 O OH OH HO B-type dimer HO OH R1 = OH R2 = H R3 = H R4 = OH A-type dimer OH H OH H = R1 = R2 = R3 = R4 = R1 = H R2 = OH R3 = H R4 = OH R1 = H R2 = OH R3 = OH R4 = H OH OH HO O OH H OH R1 R2 HO OH O H HO OH OH H OH OH OH HO O R3 O H R4 OH H H OH OH HO OH OH OH H OH H R1 = R2 = R3 = R4 = HO O R1 = H R2 = OH R3 = H R4 = OH H = H R1 = OH R2 = H R3 = H R4 = OH R1 = H R2 = OH R3 = OH R4 = H OH OH Trimer F 1: ��type ��� ��type ��������o� ���ers ��� tr��ers prese�t �� t�e �r�pe see�s� ISRN Spectroscopy 3 R1 OH R1 OH HO O+ R2 HO O OH O R2 OR 3 O OH OR OH OH O OR4 Pelargonidin R1 = H; R2 = H R = glucose; glucuronic acid Cyanidin R1 = H; R2 = OH Kaempferol R1 = H; R2 = H Delphinidin R1 = OH; R2 = OH Quercetin R1 = OH; R2 = H Peonidin R1 = OCH3; R2 = H Myricetin R1 = OH; R2 = OH Malvidin R1 = OCH3; R2 = OCH3 Isorhamnetin R1 = H; R2 = OCH3 Petunidin R1 = OCH3; R2 = OH Laricitrin R1 = OH; R2 = OCH3 H, glucose R3 = Syringetin R1 = OCH3;R2 = OCH3 3 ) BDFUZM ८IZESPYZDJOOBNZM DJT USBOT DBČFPZM (a) (b) F 2: (a) e principal monomer anthocyanins of grape: the glucose residue can be linked to an acetyl, coumaroyl, or caffeoyl group. (b) e principal �avonols of grape. cell growth in human tumors (see [4] and references cited e anthocyanin pro�le is also determined for the study herein). of grape chemotaxonomy; for example, the presence of 3,5- Stilbene compounds are the principal phytoalexins of O-diglucoside anthocyanins is used to distinguish between grape: they include cis- and trans-resveratrol (3,5,4 -trihy- V. vinifera and hybrid grape varieties, the former being droxystilbene) and their glucoside derivatives (cis- and trans- characterized by low presence or practical absence of these ′ compounds. Moreover, grape anthocyanins are antioxidant piceid), piceatannol (3,4,3 ,5 -tetrahydroxy-trans-stilbene), and natural colorants used in the nutraceutical, food, and and stilbene oligomers (viniferins).′ ′ A number of studies pharmaceutical industries [26–28]. evidenced anticancer, cardioprotection, anti-in�ammatory During the wine aging, anthocyanins are undergone and antioxidant activities, and platelet aggregation inhibition reactions with other matrix compounds, and new molecules of trans-resveratrol [7–13]. Grapevine synthesizes viniferins with different chromatic characteristics, with respect to in different parts of the plant (roots, clusters, and stems) their precursors, are formed [29]. As a consequence, the in particular -viniferin, two -viniferin glucosides, and anthocyanic pro�le of wine changes dramatically during pallidol [14, 15]. Moreover, viniferins can arise from the aging; for example, the LC-chromatogram of a 4-month aged oligomerisation of trans-resveratrol in grape tissues as active wine recorded at 520 nm shows as main signals the grape defense of the plant against exogenous attacks or could be anthocyanins, and aer 2-year aging, these signals disappear produced from resveratrol by extracellular enzymes released completely, and a broad peak due to the new anthocyanin from the pathogen in an attempt to eliminate undesirable derivatives overlaps the latter part of the chromatogram toxic compounds [16, 17]. Structures of the principal vine [30, 31]. Reaction of anthocyanins with �avan-3-ols, pro- viniferins are showed in Figure 3. cyanidins, and tannins shis the wine from purple-red to Anthocyanins are the compounds responsible for the brick-red hue, and the formation of pyranoanthocyanins, red color of grapes and wines. Principal anthocyanins of stable structures formed by reaction between anthocyanins Vitis vinifera varieties are delphinidin (Dp), cyanidin (Cy), and acetaldehyde, pyruvic acid, vinylphenol, vinylcatechol, petunidin (Pt), peonidin (Pn), and malvidin (Mv), present in vinylguaiacol, or vinyl(epi)catechin, toward orange hue [20, the skins as 3-O-monoglucoside, 3-O-acetylmonoglucoside, 21, 32–35]. and 3-O-(6-O-p-coumaroyl)monoglucoside. Oen, also Mv- More than hundred structures belonging the pigment 3-O-(6-O-caffeoyl)monoglucoside is present. More recently, families of anthocyanins, pyranoanthocyanins, direct �ava- pelargonidin (Pg) 3-O-monoglucoside was found in grape nol-anthocyanin condensation products and acetaldehyde- [24]. Oen the not V. vinifera (hybrid) red grapes also contain mediated �avanol-anthocyanin condensation products diglucoside anthocyanins with the second glucose molecule (anthocyanin linked to �avan-3-ol either directly or by ethyl linked to the C-5 hydroxyl group (structures showed in bridge), were identi�ed in red wines. Structures of principal Figure 2(a)). anthocyanin-derivatives are showed in Figure 4,[30]. 4 ISRN Spectroscopy OH HO HO OH HO OH OH OH OH HO HO HO H H H H H H O O O OH OH OH OH HO OH 2 3 4 1 OH HO HO HO HO OH H HO H HO OH OH H H H H H O HO HO H OH OH OH OH HO 5 6 7 OH OH OH HO HO OH HO H O OH OH H H O HO H H O H H H H HO H HO H OH H O OH HO HO HO O 8 OH OH 10 9 OH HO HO O OH O H OH HO H H H HO H H H OH H OH O OH OH O HO OH HO 11 12 OH HO HO HO HO OH OH O HO O H H H HO H H H H HO OH H H OH H H H H H H H O OH HO HO O OH OH OH HO OH 14 13 F 3: Continued.