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Chedea V.S.,National Research Development Institute for Animal Biology and Nutrition Balotesti IBNA | Pintea A.,University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca | Bunea A.,University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca | Braicu C.,Chiricuta Cancer Institute | And 2 more authors.
BioMed Research International | Year: 2014

The aim of this study was to evaluate the effect of the carotenoidic saponified extract of Physalis alkekengi sepals (PA) towards the lipoxygenase (LOX) oxidation of linoleic acid. Lipoxygenase activity in the presence of carotenoids, standard and from extract, was followed by its kinetic behaviour determining the changes in absorption at 234 nm. The standard carotenoids used were β -carotene (β -car), lutein (Lut), and zeaxanthin (Zea). The calculated enzymatic specific activity (ESA) after 600 s of reaction proves that PA carotenoidic extract has inhibitory effect on LOX oxidation of linoleic acid. A longer polyenic chain of carotenoid structure gives a higher ESA during the first reaction seconds. This situation is not available after 600 s of reaction and may be due to a destruction of this structure by cooxidation of carotenoids, besides the classical LOX reaction. The PA carotenoidic extract inhibiting the LOX-1 reaction can be considered a source of lipoxygenase inhibitors. © 2014 Veronica Sanda Chedea et al. Source


Mahmoud M.A.A.,Mediterranean Agronomic Institute of Chania | Mahmoud M.A.A.,Ain Shams University | Chedea V.S.,National Research Development Institute for Animal Biology and Nutrition Balotesti IBNA | Chedea V.S.,The University of Shimane | And 2 more authors.
Food Research International | Year: 2013

In this study, the behaviour of catechin (Cat) and ascorbic acid (AA) and their mixtures at different ratios was studied in view of elaborating predictions over an eventual pro-oxidant or synergistic antioxidant activity. The Co(II)-EDTA luminol chemiluminescence showed that the mixture of Cat:AA (3:1) had the highest antioxidant activity, while the mixture of Cat:AA (1:2) the most pronounced pro-oxidant activity. As the concentration of AA increases, the antioxidant behaviour of the mixture increases strongly as well. The LC-MS analysis for the two mixtures (Cat:AA at ratios of 1:2 and 1:3) revealed that the sufficient of AA accounts for the good antioxidant behaviour of catechin (Cat:AA 1:3 with an IC50 of 47.61±0.00μM and the mixture Cat:AA 1:2 with an IC50 of 75.32±0.86μM as assessed by chemiluminescence), supported by the formation of structure I (m/z 183). As its concentration decreases, the antioxidant activity drops and this is attributed to the formation of structure II (m/z 255). However, when AA becomes lesser beyond this point, a re-strengthening of the antioxidant behaviour has been observed, which may be assigned to the formation of procyanidin structures. Thus, AA may suppress the formation of procyanidin, i.e. creation of CC bonds between the catechin units. © 2013 Elsevier Ltd. Source


Trimech I.,Mediterranean Agronomic Institute of Chania | Weiss E.K.,National Research Development Institute for Animal Biology and Nutrition Balotesti IBNA | Chedea V.S.,National Research Development Institute for Animal Biology and Nutrition Balotesti IBNA | Marin D.,National Research Development Institute for Animal Biology and Nutrition Balotesti IBNA | And 4 more authors.
Phytochemical Analysis | Year: 2014

Introduction The bioactive metabolites derived from weeds have attracted the interest of the food and pharmaceutical industries due to their health benefits. Objective To evaluate the anti-oxidant and acetylcholinesterase activity of Dittrichia viscosa extracts and characterise the polyphenolic metabolites using the LC coupled with diode-array detection (DAD) and positive mode electrospray ionisation (ESI) MS method with a view to evaluating the exploitation potential of this invasive weed. Materials and methods Roots and aerial parts of D. viscosa were extracted with solvents of increasing polarity and their major polyphenolic metabolites were identified by LC - DAD/ESI(+)/MS. The total phenolic content of the extracts was determined using the Folin-Ciocalteu method, while their anti-oxidant activity was evaluated on the basis of their ability to scavenge the stable free radical 1,1-diphenyl-2- picrylhydrazyl (DPPH) and hydrogen peroxide. Thin-layer chromatography was used to screen for acetylcholinesterase inhibitors. Results Stem extracts gave the highest phenolic content, whereas the roots showed the lowest content. Twenty-five polyphenolic constituents of the extracts were tentatively characterised according to their MS and UV spectroscopic data. Among the extracts studied, roots-ethyl acetate and flowers-diethyl ether revealed the highest activity according to the DPPH and chemiluminescence assays respectively. Conclusion The metabolic profile of D. viscosa was studied and the structures of the major polyphenolic metabolites were tentatively assigned based on their MS and UV-vis spectra. The extracts exhibited high levels of anti-oxidant and acetylcholinesterase inhibitory activity and the inhibitors are probably localised mainly in flowers and roots. Copyright © 2014 John Wiley & Sons, Ltd. Source


Chedea V.S.,National Research Development Institute for Animal Biology and Nutrition Balotesti IBNA | Chedea V.S.,The University of Shimane | Choueiri L.,Mediterranean Agronomic Institute of Chania | Jisaka M.,The University of Shimane | Kefalas P.,Mediterranean Agronomic Institute of Chania
Food Chemistry | Year: 2012

The oxidation products of a previously tested prooxidant mixture of quercetin (Q) and caffeic acid (CA) at 1:2 ratio were analysed by LC-MS. The UV-Vis and MS spectra of three chromatographic peaks eluting at tR = 9.11 min, tR = 14.36 min and tR = 30.30 min were studied further. The structures of the tentatively identified compounds indicate polymeric molecules. A pentamer formed by 3 units of quercetin and 2 units of caffeic acid was attributed in the case of peaks tR = 9.11 min and tR = 14.36 min. The quercetin quinone (QQ) - a polymerization intermediate - is a fragment of the compound identified in the MS spectrum with the m/z = 323 coming from Q o-quinone m/z = 300 plus 23 from Na+. According to the UV-Vis spectrum, we suggest a different intermolecular arrangement which gives a more extended e-delocalisation. At tR = 30.30 min, the spectra helped us to tentatively identify this oxidation product as being a polymer of 4 CA units and 1 QQ. © 2012 Elsevier Ltd. All rights reserved. Source

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