Interaction of tocored with unsaturated fatty esters

Komoda, Mamoru; Harada, Ichiro

doi:10.1007/bf02631628

Cited by 19 publications

(8 citation statements)

References 12 publications

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“…Density measurements were carried out previously in methyl oleate and methyl linoleate at atmospheric pressure by several authors. ,,− A comparison between the proposed correlation (eq ) and the data report by these authors shows a good agreement (Table ). Only the data points reported by Komoda et al at 298 K for both components deviate significantly from the proposed correlation.…”

Section: Resultsmentioning

confidence: 64%

Section: Resultsmentioning

confidence: 64%

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Speed of Sound, Density, and Derivative Properties of Methyl Oleate and Methyl Linoleate under High Pressure

et al. 2013

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Speeds of sound were measured for methyl oleate and methyl linoleate (C15H30O2) at pressures up to 200 MPa along isotherms ranging from (283.15 to 393.15) K. Additional density measurements were carried out by using a U-tube densimeter up to 100 MPa from (293 to 393) K. From the integration of speed of sound, density was evaluated up to 200 MPa, and the isentropic compressibility was determined in the same p–T domain. A correlation that represents both the density and the speed of sound within their experimental uncertainties is reported to evaluate both the volume and its derivatives with respect to pressure (isothermal compressibility) and temperature (isobaric expansion).

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Section: Resultsmentioning

confidence: 64%

Section: Resultsmentioning

confidence: 64%

Speed of Sound, Density, and Derivative Properties of Methyl Oleate and Methyl Linoleate under High Pressure

et al. 2013

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“…In this addition linoleic acid bridges the 5-methyl and 6-hydroxyl of TOH and forms a new chroman ring. In a similar study (7) methyl linoleate adds under peroxidizing conditions to the 7-methyl of tocored (a TOH oxidation product).…”

Section: Introductionmentioning

confidence: 92%

Radical addition of linoleic hydroperoxides to α‐tocopherol or the analogous hydroxychroman

Gardner

Eskins

Grams

et al. 1972

Lipids

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Either linoleic acid hydroperoxide (LOOH) or methyl linoleate hydroperoxide react anaerobically with either a-tocopherol (TOH) or its model compound-2,2,5,7,8-pentamethyl-6hydroxychroman (COH)-to form principally an addition compound of the two reactants. The reaction can be catalyzed either by 1.28 X 10 -5 M Fe(III) or by proflavin (0.01%) sensitized by visible light. The presence of air in the reaction terminates the addition, and quinones become the major products from TOH or its model compound. The addition compound synthesized from COH and LOOH (a 4.9:1 ratio of 13-hydroperoxy-cis-9, trans-12-octadecadienoic acid and 9 -hy d ro p e r o xy-trans-10,cis-12-octadecadienoic acid) was used to solve structural details of the bridging function. Three isomers of the addition compound (methyl esterified) were isolated and identified as methyl 11-(2,2,5,7,8-pentam e t hy 1-6 -oxychroman)-cis-12,13-epoxytrans-9-octadecenoate; methyl 1 1-(2,2,5,7,8-p ent amethyl-6-oxychrom a n )-t rans-12,13-epoxy-trans-9-o ctade cenoate; and methyl 11-(2,2,5,7,8-pentamethyl-6-o xy chroman)-cis-9,10-epoxytrans-12-octadecenoate in order of decreasing abundance. The mechanism appears to be free radical addition brought about by the catalytic formation of alkoxy radicals from the hydroperoxide and chromanoxy radicals from TOH or its model.

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“…Antagonistic effects were also found between BHT and propyl gallate, and the combination of ellagic acid and catechin . Drawn from the knowledge about tocored and tocopherols, the underlying mechanism of the antagonistic effect may be due to their radicals’ interactions (Figure C), resulting in the decrease of theoretical stoichiometric factor ( n ) of both antioxidants . Given the antagonism between tocored and γ‐T, more future works are necessary to make sure the optimal content of both antioxidants in bulk oil systems.…”

Section: Resultsmentioning

confidence: 99%

Antioxidant Activity Evaluation of Tocored through Chemical Assays, Evaluation in Stripped Corn Oil, and CAA Assay

Zheng

Jin

Karrar

et al. 2019

Euro J Lipid Sci & Tech

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γ‐Tocopherol‐5,6‐quinone (tocored) is a crucial oxidized product of γ‐tocopherol (γ‐T) found in edible oil. Previously published studies on antioxidant activity (AOA) of tocored are not consistent. This study aims to monitor its AOA comprehensively through chemical assays (1,1‐diphenyl‐2‐picrylhydrazyl [DPPH] and ferric reducing antioxidant power [FRAP]), antioxidant evaluation in a food model system (stripped corn oil), and cellular antioxidant activity (CAA) assay, which would reasonably widen the knowledge of the AOA of γ‐T and tocored. In both DPPH and FRAP assays, tocored shows less AOA than γ‐T. Results of chemical properties in the Schaal oven test show that tocored possesses better AOA than γ‐T. Correlation coefficients of γ‐T and tocored between peroxide and K234 or p‐AnV are 0.8784–0.9875 and 0.8716–0.9879, respectively. The CAA assay also shows that tocored possesses better cellar AOA than γ‐T, with an EC50 at 21.55 µg mL−1. Drawing conclusions from the results from chemical assays, evaluation in stripped corn oil, and CAA assay, tocored is verified as a potent antioxidant in edible vegetable oils compared to γ‐T. Practical Applications: The present work widens the knowledge of antioxidant activity of tocored and gamma‐tocopherol, and contributes to the understanding of existing antioxidant activity when gamma tocopherol is depleted when edible oils are in storage and processing processes.

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Interaction of tocored with unsaturated fatty esters

Cited by 19 publications

References 12 publications

Speed of Sound, Density, and Derivative Properties of Methyl Oleate and Methyl Linoleate under High Pressure

Speed of Sound, Density, and Derivative Properties of Methyl Oleate and Methyl Linoleate under High Pressure

Radical addition of linoleic hydroperoxides to α‐tocopherol or the analogous hydroxychroman

Antioxidant Activity Evaluation of Tocored through Chemical Assays, Evaluation in Stripped Corn Oil, and CAA Assay

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