Ethoxyquin nitroxide

Kinetics of the lipoperoxyl radical-scavenging activity of indicaxanthin in solution and unilamellar liposomes

“…Our kinetic measurements in solution showed that the effectiveness of the molecule as a lipoperoxyl radical-scavenger is comparable to that of a lipid antioxidant such as vitamin E, with a stoichiometric factor approaching 2, and an inhibition constant of the same order as that reported for a-tocopherol under similar conditions [24]. The cyclic amine of betalamic acid, the building block of the betalain pigments may be envisaged as a site in the molecule active in reducing lipoperoxyl radicals, by acting similarly to the amine group of ethoxyquin, a potent chain-breaking antioxidant in lipid systems [14,15] and in vivo [29]. After Hatom donation, the polyene system of indicaxanthin may allow the formation of a resonance-stabilised aminyl radical whose reactivity will be affected by the environment.…”

“…Betalains are cationized compounds with a positive nitrogen in a polyene system. Their cyclic amine has been considered as the reactive group conferring to this class of molecules their reducing activity [14,15]. Indicaxanthin, the yellow pigment characterizing the edible fruit of the cactus Opuntia ficus indica, is the adduct of betalamic acid with proline ( Figure 1).…”

Betalains in the era of global agri-food science, technology and nutritional health

“…Their cyclic amine, which is similar to that of the antioxidant ethoxyquine (Belitz and Grosch 1987;Lin and Olcott 1995), has reasonably been considered to be the reactive group conferring to this class of molecules reducing properties. Therefore and by theory, these phytochemicals (betacyanins and betaxanthins) carries a phenolic and an acyclic amine group, which are excellent electron donors and then are able to stabilise radicals (Kanner and Harel 1985;Kanner et al 1996;Kanner et al 2001).…”

HPLC determination of ethoxyquin and its major oxidation products in fresh and stored fish meals and fish feeds

“…As a prerequisite to an investigation of the accumulation of EQ and its products in animal food products we have focused on methods for the determination of EQ oxidation products in both the fish meal and compounded fish feeds used in salmon aquaculture. The oxidation products of EQ are numerous, and only some have been identified 9–13. When EQ was added to oxidised fish meal or oxidised fish oil, a quinone imine compound (QI, 2,6‐dihydro‐2,2,4‐trimethyl‐6‐quinolone) and a dimer (DM, 1,8′‐di(1,2‐dihydro‐6‐ethoxy‐2,2,4‐trimethylquinoline)) were reported as the major oxidation products 12.…”