Tocopherol Inhibition of NO₂-Mediated Nitrosation

Starch Can Inhibit Nitrite-Dependent Oxidation of Crocin in Gastric Lumen Increasing Bioavailability of Carotenoids

“…The faster oxidation can be attributed to the oxidation of crocin by NO 2 and N 2 O 3 formed by reactions 3 and 4, respectively, in addition to the reaction of O 2 with crocin radicals. If crocin is reacted with NO 2 and/or N 2 O 3 , it can function as a scavenger of reactive nitrogen oxide species such as β-carotene and other carotenoids (Cooney et al, 1994;Everett et al, 1996).…”

Nitric Oxide: A Multitasked Signaling Gas in Plants

“…NO was suggested to be a key intermediate in the metabolism of inorganic nitrogen compound in higher plants and nitrogenfixing organisms. It was only in 1994 that NO was proved to be endogenously produced in a nonenzymatic way through conversion of nitrogen dioxide to NO by carotenoids in the light (Cooney et al, 1994). Moreover, synthesis of NO on the apoplast has also been described by a nonenzymatic mechanism, whereby nitrite is converted to NO under acid conditions in response to abscisic acid (ABA) and gibberellins (Bethke et al,2004).…”

Products of the reaction between α- or γ-tocopherol and nitrogen oxides analyzed by high-performance liquid chromatography with UV-visible and atmospheric pressure chemical ionization mass spectrometric detection

“…Three major products, namely ␣-TQ [21], TR [6,22], and dimer [25][26][27][28][29][30], were identified in the reaction of ␣-tocopherol by HPLC chromatograms of the reaction solutions under similar reaction conditions, In the case of ␥-Toc, TR, and 5-nitro-␥-tocopherol (5-NGT) [5,6,22] were obtained. These structures were determined by comparing the various spectral data with those reported in previous papers.…”

“…The main oxidation products from ␣-Toc were identified as, being ␣-tocopheryl quinone (␣-TQ) [21], tocored (TR) [22][23][24], and 2,3-dihydro-7a-(3-hydroxy-3,7,11,15-tetramethyl -hexadeca -6,10,14-trienyl )-3,5,6,9,10,11a-hexamethyl-3-3-(4,8,12-trimethyl-3,7,11-tridecatrienyl)-1H-pyrano [2,3a] xanthene-8(7aH),11(11aH)-dione (dimer) [25][26][27][28][29][30]. The products from the reaction of ␥-Toc were separated and characterized as TR and 5-nitro-␥-tocopherol (5-NGT) [6-8, 23,24,31].…”