Antioxidant Activity of Natural Phenols and Derived Hydroxylated Biphenyls

Abstract

A comparative in vitro study of the antioxidant potential of natural phenols (zingerone, curcumin, raspberry ketone, magnolol) and their synthesized derivatives was performed. The antioxidant efficiency was evaluated in blood serum obtained from healthy individuals, by means of spectrophotometry, before and after the addition of pro-oxidant tert-butyl hydroperoxide (TBH). Moreover, the antioxidant effect of an equimolar mixture of curcumin and zingerone was investigated. Interpretation of our results reveals that in the blood serum of healthy individuals curcumin (C1), raspberry ketone (RK1), magnolol (M1) and synthesized derivative of zingerone (Z2) demonstrate remarkable antioxidant effects (р < 0.05). However, in the state of TBH-induced excessive oxidative stress natural magnolol and synthesized derivatives C1, Z1 and RK1 show powerful antioxidant activity and thus can be further investigated to obtain information about their metabolic transformations and their potential influence at the cellular level. Results obtained from measurements in an equimolar mixture of zingerone and curcumin indicate synergism (р < 0.05) between the two compounds. This combination is especially successful due to the fast and efficient neutralization of added pro-oxidant TBH. The commercial availability of turmeric and ginger and their frequent combined use in diet suggest ideas for further broader utilization of the beneficial synergistic effect of their phenolic components.

Circulating Fatty Acids Associate with Metabolic Changes in Adolescents Living with Obesity

“…TAS was measured using Erel's colorimetric method with ABTS as a chromogen [24]. SOD activity was measured according to the method of Misra and Fridovich [25], while SHG concentrations were determined by Ellman's spectrophotometric method with the reaction of 2,2 ′ -dinitro-5,5 ′dithio-benzoic acid (DTNB) with aliphatic thiols [26] modified in our laboratory. An automated colorimetric method with ferrous ions was used for TOS quantification [27].…”

Childhood obesity accelerates biological ageing: is oxidative stress a link?

“…SOD activity was determined using the adrenalin method proposed by Misra and Fridovich (15) . The total concentration SHG in serum was determined through Ellman's method (16) , involving the reaction of 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) with aliphatic thiol compounds. TOS were determined by modifying of colorimetric method, with oxidation of ferrous ion-odianisidine complex to ferric ion, proportional to total oxidants protection present in sample (17) .…”

Polyphenols from Moldova wines and their involvement in antioxidant and anti-stress processes

“…Antioxidanții sunt compușii ce se supun oxidării sau inhibă reacțiile inițiale de oxigen sau peroxizi, mulți din ei (cum sunt tocoferolii) fiind utilizați drept conservanți în diferite produse (grăsimi, produse alimentare, săpunuri). În industria chimică, antioxidanții se referă de obicei la compuși ce frânează autooxidarea unui produs chimic [13]. Autooxidarea este cauzată în primul rând de reacțiile dintre oxigen și substrat.…”

“…Efectele ale antioxidanților naturali depind de absorbția hidrogenului fenolic în reacțiile radicalice, de stabilitatea radicalului antioxidant natural format în timpul reacțiilor radicalice și de substituenții prezenți în structură. Aceasta este probabil contribuția cea mai semnificativă a capacității antioxidanților naturali de a interveni în reacțiile radicalice [13]. Oxidarea reprezintă un proces redox şi constă în transferul de electroni de la o substanţă la un agent oxidant și formarea posibilă a radicalilor liberi, care provoacă reacţii distructive în lanţ.…”