Wyniki wyszukiwania dla: ANTIOXIDANTS
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Comparison of the main bioactive compounds and antioxidants in garlic and white and red onion after treatment protocols
PublikacjaPolski czosnek, biała i czerwona cebula była blanszowana, gotowana, smażona i poddawana działaniom promieniowania mikrofalowego. Następnie były w nich oznaczane m.in. takie związki jak polifenole, flawonoidy, kwas ascorbinowy i aktywne antyoksydanty. Udowodniono, że blanszowanie, smażenie i poddawanie działaniu promieniowania mikrofalowego nie wpływa znacząco na zmiejszenie zawartości badanych związków w czosnku i cebuli. Wyznaczono...
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Cardioprotection during cancer chemotherapy with the use of natural antioxidants: review of literature and results of own studies
PublikacjaDoniesienie poświęcone jest wykorzystaniu naturalnych antyoksydantów w ochronie mięśnia sercowego przed toksycznym działaniem antracyklin wykorzystywanych w leczeniu nowotworów. Pokazane zostało działanie ochronne kilku związków oraz zwierających je składników żywności w tym buraka czerwonego, który był przedmiotem badań własnych.
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The optimisation of analytical parameters for routine profiling of antioxidants in complex mixture by HPLC coupled post-column derivatisation
PublikacjaIntroduction: The wide application of natural and artificial antioxidants in food, cosmetic and pharmaceutical industry as well as the recognition of the importance of food antioxidants for supporting human health created demand for reliable and industrially applicable methods of determining antioxidative activity. This requirement can be fullfilled with the recently proposed HPLC-post-column derivatisation approach enabling the...
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Inhibition of phthalocyanine-sensitized photohemolysis of human erythrocytes by polyphenolic antioxidants: description of quantitative structure–activity relationships
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Post-Chromatographic Derivatization Coupled with Mass Spectrometry as a Method of Profiling and Identification of Antioxidants; Ligustrum vulgare Phytocomplex as an Example
PublikacjaHigh-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) coupled with radical scavenging assays, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) can be both used for the detection of the antioxidants in plant extracts. In this study, the ethanolic (70% v/v) extracts from different morphological parts of Ligustrum vulgare collected...
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Chemical and biological evaluation of antioxidant activity of endogenous redox-active compounds compared to plant-derived exogenous antioxidants
PublikacjaThe research conducted so far has shown that endogenous antioxidants, despite being regarded as the first line of antioxidant defense, may not be sufficient to maintain redox homeostasis in cells exposed to oxidative stress. The results obtained in the doctoral dissertation show that endogenous redox-active compounds were moderate or weak scavengers of ABTS and DPPH radicals, while in cellular setting, their impact on the reducing...
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Interactions between polyphenolic antioxidants quercetin and naringenin dictate the distinctive redox-related chemical and biological behaviour of their mixtures
PublikacjaFood synergy concept is suggested to explain observations that isolated antioxidants are less bioactive than real foods containing them. However, mechanisms behind this discrepancy were hardly studied. Here, we demonstrate the profound impact of interactions between two common food flavonoids (individual: aglycones quercetin—Q and naringenin—N− or their glycosides rutin—R and naringin—N+ vs. mixed: QN− and RN+) on their electrochemical...
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Effect of Co-Encapsulated Natural Antioxidants with Modified Starch on the Oxidative Stability of β-Carotene Loaded within Nanoemulsions
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A Three-Step Approach to Estimation of Reduction Potentials of Natural Mixtures of Antioxidants Based on DPPH Test; Illustration for Catechins and Cocoa
PublikacjaThe aim of this study is to propose a methodology to assess electrochemical properties of complex mixtures of antioxidants, such as plant extracts, based on the results of simple and popular DPPH test. The first, most difficult step, involves determinations of standard reduction potentials (E0) for the series of purified compounds (here catechins). The next step is the calculation of stoichiometric values (n10) based on the results...
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The impact of interactions between polyphenolic antioxidants on the redox-related chemical and biological properties of their mixtures – the extension of food synergy concept.
PublikacjaThe results of studies indicate that chemopreventive efficiency of isolated phytochemicals is lower than that of polyphenol-rich foods. This discrepancy has been ascribed to the food synergy concept that assumes additive or even synergistic influence of different food ingredients on human health. The results presented in the dissertation made it possible to propose an alternative and innovative explanation of these observations. The...