Catechins are transformed into dinitrosocatechins (diNOcats) and then oxidized to the quinones by salivary nitrite under conditions simulating the stomach. This manuscript deals with formation of stable radicals in the NO group of diNOcat during nitrite-induced oxidation of (+)-catechin and diNOcat at pH 2. We postulated two mechanisms for the stable radical formation; one is nitrous acid-induced oxidation of diNOcat in the A-ring, and the other intermolecular charge transfer from the A-ring of diNOcat and/or diNOcat quinone to the quinone moiety of the B-ring of diNOcat quinone. In addition, an unstable phenoxyl radical, which might be transformed into quinone, was also produced, accompanying the formation of the stable radical on the NO group. Taking the above results into account, we mainly focus on the adverse effects of the radicals and quinone, which may be produced from (+)-catechin in the stomach under the conditions of high salivary nitrite concentrations.
TY - JOUR
AU - Morina, Filis
AU - Takahama, Umeo
AU - Mojović, Miloš
AU - Popovic-Bijelic, Ana
AU - Veljović-Jovanović, Sonja
PY - 2016
UR - http://rimsi.imsi.bg.ac.rs/handle/123456789/939
AB - Catechins are transformed into dinitrosocatechins (diNOcats) and then oxidized to the quinones by salivary nitrite under conditions simulating the stomach. This manuscript deals with formation of stable radicals in the NO group of diNOcat during nitrite-induced oxidation of (+)-catechin and diNOcat at pH 2. We postulated two mechanisms for the stable radical formation; one is nitrous acid-induced oxidation of diNOcat in the A-ring, and the other intermolecular charge transfer from the A-ring of diNOcat and/or diNOcat quinone to the quinone moiety of the B-ring of diNOcat quinone. In addition, an unstable phenoxyl radical, which might be transformed into quinone, was also produced, accompanying the formation of the stable radical on the NO group. Taking the above results into account, we mainly focus on the adverse effects of the radicals and quinone, which may be produced from (+)-catechin in the stomach under the conditions of high salivary nitrite concentrations.
PB - Elsevier Sci Ltd, Oxford
T2 - Food Chemistry
T1 - Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin
EP - 1122
SP - 1116
VL - 194
DO - 10.1016/j.foodchem.2015.08.081
ER -
@article{
author = "Morina, Filis and Takahama, Umeo and Mojović, Miloš and Popovic-Bijelic, Ana and Veljović-Jovanović, Sonja",
year = "2016",
abstract = "Catechins are transformed into dinitrosocatechins (diNOcats) and then oxidized to the quinones by salivary nitrite under conditions simulating the stomach. This manuscript deals with formation of stable radicals in the NO group of diNOcat during nitrite-induced oxidation of (+)-catechin and diNOcat at pH 2. We postulated two mechanisms for the stable radical formation; one is nitrous acid-induced oxidation of diNOcat in the A-ring, and the other intermolecular charge transfer from the A-ring of diNOcat and/or diNOcat quinone to the quinone moiety of the B-ring of diNOcat quinone. In addition, an unstable phenoxyl radical, which might be transformed into quinone, was also produced, accompanying the formation of the stable radical on the NO group. Taking the above results into account, we mainly focus on the adverse effects of the radicals and quinone, which may be produced from (+)-catechin in the stomach under the conditions of high salivary nitrite concentrations.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Food Chemistry",
title = "Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin",
pages = "1122-1116",
volume = "194",
doi = "10.1016/j.foodchem.2015.08.081"
}
Morina, F., Takahama, U., Mojović, M., Popovic-Bijelic, A.,& Veljović-Jovanović, S.. (2016). Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin. in Food Chemistry
Elsevier Sci Ltd, Oxford., 194, 1116-1122.
https://doi.org/10.1016/j.foodchem.2015.08.081
Morina F, Takahama U, Mojović M, Popovic-Bijelic A, Veljović-Jovanović S. Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin. in Food Chemistry. 2016;194:1116-1122.
doi:10.1016/j.foodchem.2015.08.081 .
Morina, Filis, Takahama, Umeo, Mojović, Miloš, Popovic-Bijelic, Ana, Veljović-Jovanović, Sonja, "Formation of stable radicals in catechin/nitrous acid systems: Participation of dinitrosocatechin" in Food Chemistry, 194 (2016):1116-1122,
https://doi.org/10.1016/j.foodchem.2015.08.081 . .
