Phenolic profile and biological activity of table grapes (Vitis vinifera L.)

Table grapes are largely produced and consumed in the Mediterranean area. Furthermore, in the last years, the commercial interest in table grapes and other non-alcoholic grape products has notably increased worldwide. In addition to the nutritional aspects, polyphenol compounds in fresh grapes could exert positive effects on human health. The aim of this study was the characterization of the phenolic pattern of sixteen grape varieties and the evaluation of the associated antioxidant capacity and anti-inflammatory activity at gastric level. The methods used were: 1) Folin-Cocalteau\u2019s assay for the quantification of total polyphenol content; 2) High-Performance Liquid Chromatography (HPLC) coupled with Diode-Array Detector (DAD) to perform the quantitative analysis of grapes phenolic fraction 3) DPPH (1,1,-diphenil-2-picrylhydrazyl) spectrophotometric assay for the assessment of radical scavenging activity; 4) assessment of IL-8 release from human gastric epithelial cells to evaluate the anti-inflammatory activity of grape extracts. Some grapes, including seedless varieties, showed that the phenolic pattern was highly correlated with the biological activities, and, in particular, with peel and seeds portion. These results suggest that selected grape varieties could represent, also for consumers who do not drink wine, a source of healthy compounds potentially able to counteract oxidative stress and gastric inflammation

Phenolic profile and antioxidant activity of different grape (Vitis vinifera L.) varieties

In the last years, the interest in non-alcoholic grape products has considerably increased. Table grapes are largely produced in the Mediterranean area and their consumption has raised worldwide. Beside the positive pattern of nutrients, table grapes could provide benefits on human health. Among the health-promoting substances contained in table grapes, flavonoids (mainly anthocyanins, flavan-3-ols and flavonols) seem to be the most interesting. The aim of this study was the characterization of the phenolic pattern of sixteen grape varieties, and the evaluation of the associated antioxidant activity. The methods were: 1) Folin-Cocalteau's assay for the quantification of total polyphenol content; 2) DPPH (1,1,-diphenil-2—picrylhydrazyl) assay and 3) ORAC (Oxygen Radical Absorbance Capacity) spectrophotometric assays for the assessment of radical scavenging activity; 4) High Performance Liquid Chromatography (HPLC) method, coupled with electrospray ionization mass spectrometer (ESI-MS) and DAD detector was developed in order to obtain the phenolic pattern of grape samples. Data obtained in this study underline that some table grape varieties can show interesting phenolic pattern independently from the presence or not of seeds. This observation suggests that selected varieties of seedless grapes could represent an interesting source of healthy compounds, satisfying consumers' preferences and reducing concerns versus alcoholic beverages

Dephasing of coupled spin qubit system during gate operations due to background charge fluctuations

It has been proposed that a quantum computer can be constructed based on electron spins in quantum dots or based on a superconducting nanocircuit. During two-qubit operations, the fluctuation of the coupling parameters is a critical factor. One source of such fluctuation is the stirring of the background charges. We focused on the influence of this fluctuation on a coupled spin qubit system. The induced fluctuation in exchange coupling changes the amount of entanglement, fidelity, and purity. In our previous study, the background charge fluctuations were found to be an important channel of dephasing for a single Josephson qubit.Comment: 10 pages, 7 figure. to be publishe

Dereplication of sclerotiorin-like azaphilones produced by Penicillium meliponae using LC-MS/MS analysis and molecular networking.

Penicillium meliponae, a recently described and rare species, was isolated as an endophytic fungus from the Amazonian plant Duguetia sthelechantha, and has been proven to be a pigment producer. Considering the high productivity of this species and the lack of data on its chemical composition, the present study aimed to characterize the chemical profile of P. meliponae and evaluate the influence of agitation and the use of different culture media. For this purpose, liquid chromatography coupled with mass spectrometry (LC-MS/MS) and molecular networking were used, allowing the identification of 17 azaphilone molecules with sclerotiorin-like skeletons, becoming the first chemical report of this species. In addition, the different production patterns in the tested culture media were indicative that this species is sensitive to changes in the composition of the carbon source and to the presence of agitation. Furthermore, this work contributes to the fragmentation mechanisms of the different possible structural arrangements for azaphilones of the sclerotiorin type and serves as a repository of information on the gas-phase behavior of this type of metabolite in mass spectrometry experiments and will assist future studies aimed at the discovery of azaphilones

Light Sterile Neutrinos: A White Paper

This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data