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Madrid, Spain

Panzella L.,University of Naples Federico II | Verotta L.,University of Milan | Goya L.,ICTAN | Ramos S.,ICTAN | And 4 more authors.
Journal of Agricultural and Food Chemistry | Year: 2013

Novel polyfunctionalized antioxidants, 5-S-lipoylhydroxytyrosol (1) and its disulfide 2, trisulfide 3, and tetrasulfide 4, were prepared from tyrosol and dihydrolipoic acid in the presence, when appropriate, of sulfur. Compound 1 exhibited significant activity in the ferric reducing/antioxidant power (FRAP) assay (1.60 Trolox equiv), whereas polysulfides 2-4 were more efficient in the DPPH reduction assay (88-93% reduction vs 68% by Trolox). At 10 μM concentration, all compounds 1-4 proved to be efficient hydroxyl radical scavengers (56-69% inhibition) in a Fenton reaction assay. When administered to human HepG2 cells, 1-4 proved to be nontoxic and exhibited marked protective effects against reactive oxygen species (ROS) generation (60-84% inhibition at 1 μM concentration) and cell damage induced by 400 μM tert- butylhydroperoxide. All compounds 1-4 exhibited overall greater antioxidant activity than hydroxytyrosol. © 2012 American Chemical Society.

Most analytical studies on polyphenols in cereals refer to compounds determined in aqueous-organic extracts and alkali hydrolysates, but an appreciable amount of polyphenols bound to cell wall constituents may remain insoluble in the residues of extraction and alkali hydrolysis. The main objective of this work was to determine if sulphuric acid hydrolysis may release significant amounts of polyphenols to be considered for analytical and nutritional studies. HPLC/MS analyses of polyphenols were performed in methanol-acetone extracts, alkali and sulphuric acid hydrolysates of wheat flour, bran and a pool of cereals of the diet. The amount of polyphenols found in the acidic hydrolysates (200-1600 mg/100 g) was higher than in alkali hydrolysates (0.2-372 mg/100 g). Lower amount of polyphenols were found in the methanol-acetone extracts (44-160 mg/100 g). Hydroxybenzoic, caffeic, cinammic, ferulic and protocatechuic acids were the main constituents of the hydrolysates. The contribution of cereals to the intake of dietary polyphenols in Spain was estimated around 360 mg/person/day (65 mg of extractable and 295 mg nonextractable polyphenols). It was concluded that the acidic hydrolysis, usually omitted in analysis of polyphenols in cereals, may be allow to obtain polyphenol contents closer to the actual values. © 2010 Elsevier Ltd. All rights reserved.

Arranz S.,ICTAN | Silvan J.M.,ICTAN | Saura-Calixto F.,ICTAN
Molecular Nutrition and Food Research | Year: 2010

Scope: Dietary polyphenols (PP) can be divided into two groups: extractable polyphenols (EPP) or compounds solubilized by aqueous organic solvents, and nonextractable polyphenols (NEPP) or compounds that remain in their corresponding extraction residues. Most studies on food polyphenols and dietary intakes address exclusively EPP. The objective of this work was to determine the actual amount of PP, including NEPP, in food and in a whole diet.Methods and results: HPLC-MS analyses were performed to identify EPP in methanol-acetone extracts and NEPP in the acidic hydrolyzates of their extraction residues in cereals, fruits, vegetables, nuts, and legumes. NEPP contents, estimated as hydrolyzable PP plus nonextractable proanthocyanidins (PA), ranged from 880 mg/100 g dry weight in fruits to 210 mg/100 g in cereals and were substantially higher than the contents of EPP. NEPP intake (day/person) in the Spanish diet (942 mg) is higher than EPP intake (258 mg) fruits and vegetables (746 mg) are the major contributors to the total PP intake (1201 mg).Conclusion: Non extractable polyphenols are the major part of dietary polyphenols. The knowledge of intakes and physiological properties of NEPP may be useful for a better understanding of the potential health effects of dietary PP. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Panzella L.,University of Naples Federico II | Cerruti P.,CNR Institute of Neuroscience | Ambrogi V.,University of Naples Federico II | Agustin-Salazar S.,CNR Institute of Neuroscience | And 8 more authors.
ACS Sustainable Chemistry and Engineering | Year: 2016

Treatment with boiling 6 M HCl increases up to 30 times the intrinsic antioxidant potency of spent coffee grounds, leading to a versatile multifunctional material (hydrolyzed spent coffee grounds, HSCG). Spectral and morphological analyses suggest that the remarkable potentiation of the antioxidant activity is due to efficient removal of the hydrolyzable components, mainly carbohydrates, making the polyphenol-rich component available for interaction with free radicals and oxidizing species. HSCG efficiently protects hepatocarcinoma (HepG2) cells from oxidative stress-induced injury and delays lipid peroxidation in fish and soybean oils. Moreover, films made of polyethylene/2% HSCG blends display greater stability to thermal and photo-oxidative degradation. HSCG may thus represent an easily accessible and sustainable alternative to currently available biomaterials with intrinsic antioxidant properties for biomedical, industrial, and technological applications. © 2016 American Chemical Society.

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