Search results for "PHENOLS"
showing 10 items of 766 documents
Oxidovanadium(v) complexes with l-proline-based amino acid phenolates
2019
L-proline was used to prepare chiral, tridentate amino acid phenol proligands H2L1—4. These proligands react with vanadium precursors VO(acac)2, VOSO4 ∙ 5 H2O and VO(OPr)3 in methanol to form the corresponding oxidoalkoxidovanadium(V) complexes 1—4. The complexes crystallize from methanol, and are octahedrally coordinated with a general formula [VO(L1—4)(OMe)(MeOH)]. In solution, however, they adopt several different conformations or isomeric structures depending on the solvent. peerReviewed
Green and Quick Extraction of Stable Biophenol-Rich Red Extracts from Grape Processing Waste
2021
The extraction of grape processing waste (wine pomace) via microwave-hydrodiffusion and gravity (MHG) from three different cultivars grown in Sicily (Syrah, Perricone and Nero d’Avola) rapidly affords aqueous extracts highly concentrated in valued biophenols including flavonoids, anthocyanins and phenolic acids. The method does not employ organic solvent, acid or base and does not require grinding or freeze drying of the wine pomace nor separation of the grape skins from seeds and stem. All the extracts have a pronounced stability as shown by their red-violet color fully retained after storage for more than a year (15 months) in freezer under air. Concentrations of phenolics up to…
Behaviour of some compounds with lmax at 280 nm in determination of total flavonoids of grape skin extracts made from a hydroalcoholic SO2-rich solve…
2010
This paper reports the results of a study on the ambiguous behaviour of substances with lmax at 280 nm in the determination of total flavonoids in whole grape skin extracts made from a hydroalcoholic SO2-rich solvent, apparently not eluted with methanol after absorption on a C18 cartridge employed for sample pre-concentration and SO2 removal. After rejecting the hypothesis that they were irreversibly absorbed on the C18 cartridge, it seemed that they reacted with other phenolics during passage through the C18 cartridge and were totally eluted with methanol in this new combined form. This new hypothesis seems very probable and is in accord with the more recent acquisition about the synthesis…
Effect of different processing methods on the quality of obtained pomegranate juice
2019
Pomegranate juice has many health properties as the fruits contain anticarcinogenic, antimicrobial and antiviral compounds. Its consumption has greatly increased throughout the world in recent years due to the potential of its different components, polyphenols and anthocyanins mostly. Many studies have been performed on the pomegranate juice yield demonstrating its influence on the organoleptic and physicochemical properties of the juice. Commercial pomegranate juice production involves pressing the fruits. As a consequence, there is a need to investigate the pressing machine types and adjustment in order to maximize juice yield and enhance its health properties. The aim of this study was t…
Investigating the Antiproliferative and Antioxidant Properties of Pancratium maritimum L. (Amaryllidaceae) Stems, Flowers, Bulbs, and Fruits Extracts
2018
Pancratium maritimumstems, flowers, bulbs, and fruits extracts were investigated for their antiproliferative and antioxidant properties. Total phenols and total flavonoids were also determined. Thein vitroantiproliferative activity was tested against seven cancer cell lines such as C32, HeLa, MDA-MB-231, PC3, A549, MCF-7, and LNCaP by using SRB assay. Interesting results were obtained with stems ethanol extract (ET1) against C32 cells (IC50of 27.1μg/mL) and fruits aqueous extract (AQ) against MCF-7 cell line (IC50of 36.5μg/mL). To define the antioxidant activity, four tests such as DPPH, ABTS FRAP, andβ-carotene bleaching tests were used.The most promising ABTS scavenging capacity was obser…
Species-Specific Antioxidant Power and Bioactive Properties of the Extracts Obtained from Wild Mediterranean Calendula Spp. (Asteraceae)
2019
In this study we focused on four taxa of the genus Calendula (C. maritima, C. suffruticosa subsp. fulgida, C. arvensis, and the hybrid between the first two ones), collected in Mediterranean area (Sicily). Six extracts for each species were obtained using solvents with increasing polarity (hexane, ethanol 80%, acetone 70%, and water) and through extraction by supercritical fluids (SFE). It has been observed that the solvent with the highest extraction efficiency was ethanol 80% for all species. However, SFE extracts showed high antioxidant activity comparable to the ethanol 80% extract (polyphenol, DPPH, and reducing power method). These findings were confirmed by in vitro analysis (MTT ass…
Oxidation Processes in Sicilian Olive Oils Investigated by a Combination of Optical and EPR Spectroscopy
2012
: Extra virgin olive oil (EVOO) is recognized as one of the healthiest foods for its high content of antioxidants, which forestall and slow down radical formation. Free radical-initiated oxidation is considered one of the main causes of rancidity in fats and oils. As a consequence, reliable protocols for the investigation of oil oxidation based on selective, noninvasive, and fast methods are highly desirable. Here we report an experimental approach based on UV-Vis absorbance, steady-state fluorescence, and electron paramagnetic resonance (EPR) spectroscopy for studying oxidation processes induced by temperature for a period up to 35 d on Sicilian EVOO samples. We followed the decrease in β…
Tunisian tomato by-products, as a potential source of natural bioactive compounds.
2016
Consumption of tomato and tomato products is positively related to the reduction in cardiovascular disease and several types of cancer, thanks to the presence of natural compounds, such as antioxidants. Peels and seeds fractions of tomato, collected after industrial processing in Tunisian industries, were analysed for nutritional and antioxidants composition in perspective of its utilisation. Proximate composition, fatty acids profile, carotenoids, such as lycopene and beta-carotene, polyphenols contents, demonstrated the good potential of these residual products as a source of natural compounds, useful for food and nutraceuticals applications.
Chemical Profile and Biological Activity of Cherimoya (Annona cherimola Mill.) and Atemoya (Annona atemoya) Leaves
2020
Annona cherimola (Cherimoya) and Annona atemoya (Atemoya) are tropical plants known for their edible fruit. Scientific data suggest that their leaves, used in traditional medicine in the form of teas or infusions without evidence of toxicity, contain several bioactive compounds. However, only Annona muricata among all the Annona species is currently used in the nutraceutical field, and its dried leaves are marketed for tea preparation. In this work, we explored the nutraceutical potential of Atemoya and Cherimoya leaves, by evaluating their chemical profile and functional properties. Phytochemical analyses showed large amounts of phenolic compounds, in particular proanthocyanidins, and iden…
Green biotechnology for valorisation of residual biomasses in nutraceutic sector: Characterization and extraction of bioactive compounds from grape p…
2019
The grape pomace (GP) is an important by-product of winemaking, accounting for about 13-25% of the grapes processed. The aim of this work was to investigate the nutritional and antioxidant composition of GP obtained from Nero d’Avola (NA) grape, one of the most important indigenous varieties in Italy, in order to verify application in nutraceutics. Seeds and skin of the GP were studied for their nutritional and antioxidants composition, fatty acid and polyphenols profile, bioactives properties in vitro, by gravimetric, spectrophotometric and chromatographic techniques. The results showed that NAGP seeds are rich in the beneficial polyunsaturated fatty acids and that the polyphenols extracte…