110 research outputs found
Methyl salicylate glycosides in some Italian varietal wines
Glycosides are ubiquitous plant secondary metabolites consisting of a non-sugar component called an aglycone, attached to one or more sugars. One of the most interesting aglycones in grapes and wine is methyl salicylate (MeSA), an organic ester naturally produced by many plants, particularly wintergreens. To date, nine different MeSA glycosides from plants have been reported, mainly spread over the genera Gaultheria, Camellia, Polygala, Filipendula, and Passiflora. From a sensorial point of view, MeSA has a balsamic-sweet odor, known as Wintergreen. MeSA was found in Vitis riparia grapes, in Vitis vinifera sp. and in the Frontenac interspecific hybrid. We found that the MeSA glycosides content in Verdicchio wines and in some genetically related varieties (Trebbiano di Soave and Trebbiano di Lugana) was very high. In order to understand which glycosides were present in wine, the methanolic extract of Verdicchio wine was injected into a UPLC-Q-TOF-HDMS and compared to the extracts of different plants rich in such glycosides. Using pure standards, we confirmed the existence of two glycosides in wine: MeSA 2-O-β-d-glucoside and MeSA 2-O-β-d-xylopyranosyl (1-6) β-d-glucopyranoside (gaultherin). For the first time, we also tentatively identified other diglycosides in wine: MeSA 2-O-α-l-arabinopyranosyl (1-6)-β-d-glucopyranoside (violutoside) and MeSA 2-O-β-d-apiofuranosyl (1-6)-β-d-glucopyranoside (canthoside A), MeSA 2-O-β-d-glucopyranosyl (1-6)-O-β-d-glucopyranoside (gentiobioside) and MeSA 2-O-α-l-rhamnopyranosyl (1-6)-β-d-glucopyranoside (rutinoside). Some of these glycosides have been isolated from Gaultheria procumbens leaves by preparative liquid chromatography and structurally annotated by 1H- and 13C-NMR analysis. Two of the peaks isolated from Gaultheria procumbens leaves, namely MeSA sambubioside and MeSA sophoroside, were herein observed for the first time. Six MeSA glycosides were quantified in 64 Italian white wines, highlighting the peculiar content and pattern in Verdicchio wines and related cultivars. The total concentration in bound and free MeSA in Verdicchio wines varied in the range of 456–9796 μg/L and 5.5–143 μg/L, respectively, while in the other wines the bound and free MeSA was below 363 μg/L and 12 μg/L, respectively. As this compound’s olfactory threshold is between 50 and 100 μg/L, our data support the hypothesis that methyl salicylate can contribute to the balsamic scent, especially in old Verdicchio wine
Characterization of the neuroactive compound profle in organic, conventional and processed tomatoes
Combining molecular and metabolomic analysis to evaluate transgenic Vitis vinifera plants expressing the Vitreoscilla haemoglobin (VHb)
Transgenic V. vinifera 'Brachetto' plants expressing Vitreoscilla stercoraria haemoglobin gene (vhb) were obtained by transferring the pBI-VHb construct harbouring the vhb and the nptII genes, via A. tumefaciens EAH 105. From 18 distinct transgenic plantlets, 2 lines were randomly chosen and 11 and 14 plants respectively obtained by micropropagation were acclimated for 100 days in the greenhouse, together with 10 micropropagated plants of a wild-type control line. A data-driven assessment, aimed at evaluating all measurable lowmolecular weight organic compounds in these transgenic plants was performed using UPLC-Q-TOF with an ESI interface. Comparisons between controls and transgenic lines and between the two transgenic lines detected significant differences in some metabolic patterns. For each line, a list of identified compounds was extracted from the 100 most significant biomarkers
The effect of static and dynamic low oxygen regimes during postharvest storage on ‘Granny Smith’ apple is disclosed by transcriptome and metabolic surveys
Semi-Targeted Profiling of the Lipidome Changes Induced by Erysiphe Necator in Disease-Resistant and Vitis vinifera L. Varieties
The ascomycete Erysiphe necator is a serious pathogen in viticulture. Despite the fact that some grapevine genotypes exhibit mono-locus or pyramided resistance to this fungus, the lipidomics basis of these genotypes’ defense mechanisms remains unknown. Lipid molecules have critical functions in plant defenses, acting as structural barriers in the cell wall that limit pathogen access or as signaling molecules after stress responses that may regulate innate plant immunity. To unravel and better understand their involvement in plant defense, we used a novel approach of ultra-high performance liquid chromatography (UHPLC)-MS/MS to study how E. necator infection changes the lipid profile of genotypes with different sources of resistance, including BC4 (Run1), “Kishmish vatkhana” (Ren1), F26P92 (Ren3; Ren9), and “Teroldego” (a susceptible genotype), at 0, 24, and 48 hpi. The lipidome alterations were most visible at 24 hpi for BC4 and F26P92, and at 48 hpi for “Kishmish vatkhana”. Among the most abundant lipids in grapevine leaves were the extra-plastidial lipids: glycerophosphocholine (PCs), glycerophosphoethanolamine (PEs) and the signaling lipids: glycerophosphates (Pas) and glycerophosphoinositols (PIs), followed by the plastid lipids: glycerophosphoglycerols (PGs), monogalactosyldiacylglycerols (MGDGs), and digalactosyldiacylglycerols (DGDGs) and, in lower amounts lyso-glycerophosphocholines (LPCs), lyso-glycerophosphoglycerols (LPGs), lyso-glycerophosphoinositols (LPIs), and lyso-glycerophosphoethanolamine (LPEs). Furthermore, the three resistant genotypes had the most prevalent down-accumulated lipid classes, while the susceptible genotype had the most prevalent up-accumulated lipid classes
A Metabolomic Approach to the Study of Wine Micro-Oxygenation
Wine micro-oxygenation is a globally used treatment and its effects were studied here by analysing by untargeted LC-MS the wine metabolomic fingerprint. Eight different procedural variations, marked by the addition of oxygen (four levels) and iron (two levels) were applied to Sangiovese wine, before and after malolactic fermentation
A targeted metabolomics method for the rapid quantification of multiple classes of phenolics in the fruits of Rosaceae
In recent years, the interest in phenolic compounds has been increasing due to
compelling evidences of their beneficial health properties and to their impact on food quality. The complexity and remarkable diversity of phenolics has challenged the
analytical performances of separation and detection methods in terms of resolving
power, selectivity and sensitivity for the identification and quantification of these
compounds in different matrices. Targeted metabolomics is a strategy based on the use
of predefined metabolite‐specific signals, such as MRM transitions, that can be used to
accurately determine the concentrations of a wide range of known metabolites. We developed a rapid and versatile UPLC‐MS/MS based method for the quantification of
>150 phenolics, such as benzoates, phenylpropanoids, coumarins, stilbenes,
dihydrochalcones and flavonoids in fruits. Compounds commonly occurring in plants
were included in the method together with metabolites specific of a single species or
family. Reverse‐phase chromatography was optimised to achieve separation of the
compounds over 15 min, reducing possible ion suppression effects and resolving many
isomeric compounds. The optimal fragmentation conditions for each analyte were studied and MRM transitions were selected for accurate quantification. The
effectiveness of the method was validated by studying the limits of detection and
quantification, the linearity ranges of the instrumental response and the repeatability of the analysis. The method was successfully applied and validated for the analysis of apples, cherries, raspberries, strawberries, as well as grape, wine and green tea, and was shown to represent a valuable tool for the quantitative evaluation of the chemical phenotype, measuring the presence, amount and natural variance in phenolics composition of these fruits
Red grape varieties differ both in the amount and in the structure of their skin and seed tannins extractable into wine
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