Search results for "Vitis"
showing 10 items of 457 documents
Molecular analysis of differential antiproliferative activity of resveratrol, epsilon viniferin and labruscol on melanoma cells and normal dermal cel…
2018
IF 3.778 (2016); International audience; Very recently, we have produced new resveratrol derived compounds, especially labruscol by culture of elicited grapevine cell suspensions (Vitis labrusca L.). This new polyphenolic oligomer could function as cancer chemopreventive agent in similar manner of resveratrol. In this study, we have determined the efficiency of resveratrol, ε-viniferin and the labruscol on human melanoma cell with or without metastatic phenotype. Our results show a differential activity of the three compounds where the resveratrol remains the polyphenolic compound with the most effective action compared to other oligomers. These three compounds block cell cycle of melanoma …
Lasiolactols A and B Produced by the Grapevine Fungal Pathogen Lasiodiplodia mediterranea
2016
A strain of Lasiodiplodia mediterranea, a fungus associated with grapevine decline in Sicily, produced several metabolites in liquid medium. Two new dimeric c-lactols, lasiolactols A and B (1 and 2), were characterized as (2S*,3S*,4R*,5R*,20S*,30S*,40R*,50R*)-and (2R*,3S*,4R*,5R*,20R*,30S*,40R*,50R*)-(5-(4-hydroxymethyl-3,5-dimethyl-tetrahydrofuran- 2-yloxy)-2,4-dimethyl-tetrahydro-furan-3-yl]-methanols by IR, 1D-and 2D-NMR, and HR-ESI-MS. Other four metabolites were identified as botryosphaeriodiplodin, (5R)-5-hydroxylasiodiplodin, (-)-(1R, 2R)-jasmonic acid, and (-)-(3S, 4R, 5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone (3 - 6, resp.). The absolute configuration (R) at hydroxylated s…
Hyperosmolarity and Benzalkonium Chloride Differently Stimulate Inflammatory Markers in Conjunctiva-Derived Epithelial Cells in vitro
2017
Tear hyperosmolarity is known to cause ocular surface inflammation in dry eye syndrome. Benzalkonium chloride (BAK), an eyedrop preservative, is known to induce dry eye in long-term-treated patients. Analyzing the modulation of the proinflammatory potential of hyperosmolarity in the presence of BAK on the conjunctiva could give new insights into the effect of this preservative on the disease. In a hyperosmolar model on a conjunctiva-derived cell line, and in the presence of BAK, we evaluated key inflammatory markers [CCL2, IL-8, IL-6, macrophage migration inhibitory factor (MIF) and intercellular adhesion molecule (ICAM)-1] as well as the osmoprotectant element nuclear factor of activated T…
Starter cultures as biocontrol strategy to prevent Brettanomyces bruxellensis proliferation in wine
2017
Brettanomyces bruxellensis is a common and significant wine spoilage microorganism. B. bruxellensis strains generally detain the molecular basis to produce compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols that derive from the sequential bioconversion of specific hydroxycinnamic acids such as ferulate and p-coumarate. Although B. bruxellensis can be detected at any stage of the winemaking process, it is typically isolated at the end of the alcoholic fermentation (AF), before the staring of the spontaneous malolactic fermentation (MLF) or during barrel aging. For this reason, the endemic diffusion of B. bruxellensis leads to c…
Cells-qPCR as a direct quantitative PCR method to avoid microbial DNA extractions in grape musts and wines.
2017
A novel quantitative PCR assay called Cells-qPCR has been developed for the rapid detection and quantification of yeasts, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) directly from grape must and wine that does not require DNA extraction. The assay was tested on Brettanomyces bruxellensis, Saccharomyces cerevisiae, Lactobacillus plantarum, Oenococcus oeni, Acetobacter aceti and Gluconobacter oxydans in culture media, and in white and red grape musts and wines. Standard curves were constructed from DNA and cells for the six target species in all the matrices. Good efficiencies were obtained for both when comparing DNA and cells standard curves. No reaction inhibition was observe…
Electrochemical identification of toxigenic fungal species using solid-state voltammetry strategies.
2018
An electrochemical methodology for the characterization of mycotoxin-producing fungal species from the genera Aspergillus and Fusarium using solid-state voltammetry is described. Upon attachment of fungal colony microsamples to glassy carbon electrodes in contact with aqueous acetate buffer, characteristic voltammetric signals mainly associated to the oxidation of polyphenolic metabolites are recorded. The possibility of fungi-localized electrochemical processes was assessed by means of electron microscopy and field emission scanning electrochemical microscopy coupled to the application of oxidative potential inputs. Using pattern recognition methods, the determined voltammetric profiles we…
Exploring the biodiversity of two groups of Oenococcus oeni isolated from grape musts and wines: Are they equally diverse?
2016
One hundred and four Oenococcus oeni isolates were characterised by the carbohydrate fermentation (CH) profile and DNA fingerprinting. Forty-four isolates came from grape must, and 60 from wines sampled at the end of alcoholic fermentation or during malolactic fermentation. The grape must isolates fermented more CH than the wine isolates. In genotypical terms, no clear boundary between grape must and wine isolates was found. Diversities were deduced by considering the isolates of grape must and of wine separately and jointly. By considering only CH fermentation abilities, the group of grape must isolates gave higher diversity index (DICH) values than those isolated from wine; i.e., these is…
Alternative yeasts for winemaking: Saccharomyces non-cerevisiae and its hybrids
2017
Wine fermentation has not significantly changed since ancient times and the most traditional aspects are seen by the market as elements that uplift wine nuances and quality. In recent years, new trends have emerged from the sector in line with consumer preferences, and due to the effects of global climate change on grape ripening. In the first cases, the consumers are looking for wines with less ethanol and fruitier aromas and in the second cases the wineries want to reduce the wine alcohol levels and/or astringency. New yeast starters of alternative Saccharomyces species and their hybrids can help to solve some problems that wineries face. In this article we review several physiological an…
Isolation, identification and oenological characterization of non-Saccharomyces yeasts in a Mediterranean island
2016
UNLABELLED We isolated, identified and characterized yeast strains from grapes, and their fermented musts, sampled in the small island of Linosa, where there are no wineries and therefore the possibility of territory contamination by industrial strains is minimal. By traditional culture-dependent methods, we isolated 3805 colonies, distinguished by molecular methods in 17 different species. Five hundred and forty-four isolates were analysed for the main oenological characteristics such as fermentative vigour with and without sulphites, sugar consumption and production of alcohol, volatile acidity, hydrogen sulphide, glycerol and β-glucosidase. This analysis identified Kluyveromyces marxianu…
The relative abundance of hemocyte types in a polyphagous moth larva depends on diet.
2016
7 pages; International audience; Hemocytes are crucial cells of the insect immune system because of their involvement in multiple immune responses including coagulation, phagocytosis and encapsulation. There are various types of hemocytes, each having a particular role in immunity, such that variation in their relative abundance affects the outcome of the immune response. This study aims to characterize these various types of hemocytes in larvae of the grapevine pest insect Eupoecilia ambiguella, and to assess variation in their concentration as a function of larval diet and immune challenge. Four types of hemocytes were found in the hemolymph of 5th instar larvae: granulocytes, oenocytoids…