The preparation and characterization of two vitamin E analogs-sydnonimine conjugates, delta-tocopheryloxycarbonyl-3-morpholinosydnonimine (2) and troloxoxycarbonyl-3-morpholinosydnonimine (3), in which the hydroxyl group of the tocopheryl moieties is linked via an enzymatically cleavable urethane group to the sydnone moiety is described. In the presence of porcine liver esterase, these tocopheryl-sydnonimine conjugates generated the expected antioxidant moieties, i.e., delta-tocopherol or Trolox, and were found to convert oxyhemoglobin to methemoglobin at 37 degrees C in 50 mM phosphate buffer at pH 7.4, thus providing evidence for nitric oxide release. Their potency as antioxidants was indirectly studied by associating the two products of the hydrolysis, SIN-1, and delta-tocopherol or Trolox. Our findings suggest that unlike the other members of the sydnonimine family these chromane-sydnonimine derivatives do not act as peroxynitrite donors, and require enzymatic bioactivation before nitric oxide or nitroxyl anion (NO(-)) can be released.
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http://dx.doi.org/10.1016/j.niox.2006.03.006 | DOI Listing |
Antioxidants (Basel)
November 2024
Department of Food Technology, Marine Research Institute (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain.
Int J Mol Sci
June 2019
School of Chemical and Physical Sciences, Lennard-Jones Building, Keele University, Staffordshire ST5 5BG, UK.
Retinoids are present in human tissues exposed to light and under increased risk of oxidative stress, such as the retina and skin. Retinoid cation radicals can be formed as a result of the interaction between retinoids and other radicals or photoexcitation with light. It has been shown that such semi-oxidized retinoids can oxidize certain amino acids and proteins, and that α-tocopherol can scavenge the cation radicals of retinol and retinoic acid.
View Article and Find Full Text PDFEur J Pharmacol
April 2018
Division of Hygienic Chemistry, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan. Electronic address:
Crizotinib is an inhibitor of anaplastic lymphoma kinase (ALK) and is of significant therapeutic benefit to patients with non-small cell lung cancer (NSCLC) harboring the EML4-ALK fusion gene. In the present study, we demonstrated that α-tocopherol, a major component of vitamin E, attenuated the effects of crizotinib independently of its anti-oxidant properties. α-Tocopherol significantly inhibited crizotinib-induced apoptosis in cells transformed by EML4-ALK.
View Article and Find Full Text PDFJ Food Sci
July 2012
Inst. des Régions Arides de Médenine, Laboratoire d'Aridoculture et Cultures Oasiennes, Médenine 4119, Tunisia.
This article aims to determine the phenolic, tocopherol contents, and antioxidant capacities from fruits (juices, peels, and seed oils) of 6 Tunisian pomegranate ecotypes. Total anthocyanins were determined by a differential pH method. Hydrolyzable tannins were determined with potassium iodate.
View Article and Find Full Text PDFBiomed Chromatogr
October 2012
Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas and Universidad de Valladolid, Sanz y Fores s/n, Valladolid, Spain.
A method for the simultaneous determination of lipoic acid and/or Trolox methyl ether, along with α-, γ- and δ-tocopherol was developed using liquid chromatography-tandem mass spectrometry with negative electrospray ionization (HPLC-ESI-MS/MS) in an ion-trap mass spectrometer. Detection and quantification were accomplished by a multiple reaction monitoring method, using specific transitions from precursor ion to product ion for each analyte. Chromatographic separation was achieved in a 12 min run using a C(18) -bonded phase and methanol-aqueous ammonium acetate elution gradient.
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