Search Results - "Land, Edward J."

Scavenging of Cation Radicals of the Visual Cycle Retinoids by Lutein, Zeaxanthin, Taurine, and Melanin by Rozanowska, Malgorzata, Edge, Ruth, Land, Edward J, Navaratnam, Suppiah, Sarna, Tadeusz, Truscott, T George

“…In the retina, retinoids involved in vision are under constant threat of oxidation, and their oxidation products exhibit deleterious properties. Using pulse…”
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Scavenging of Retinoid Cation Radicals by Urate, Trolox, and α-, β-, γ-, and δ-Tocopherols by Rozanowska, Malgorzata, Edge, Ruth, Land, Edward J, Navaratnam, Suppiah, Sarna, Tadeusz, Truscott, T George

“…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…”
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Free Radical Coupling of o‑Semiquinones Uncovered by Pezzella, Alessandro, Crescenzi, Orlando, Panzella, Lucia, Napolitano, Alessandra, Land, Edward J, Barone, Vincenzo, d’Ischia, Marco

“…As a rule, o-semiquinones decay through disproportionation leading to equimolar amounts of catechol and o-quinone products. However, the o-semiquinone 1S…”
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Tyrosinase Autoactivation and the Chemistry of ortho-Quinone Amines by Land, Edward J, Ramsden, Christopher A, Riley, Patrick A

“…Tyrosinase oxidizes tyrosine to dopaquinone, which undergoes nonenzymatic reactions leading to precursors of melanin pigments. Cyclization of dopaquinone gives…”
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Cyclic Structural Motifs in 5,6-Dihydroxyindole Polymerization Uncovered: Biomimetic Modular Buildup of a Unique Five-Membered Macrocycle by Arzillo, Marianna, Pezzella, Alessandro, Crescenzi, Orlando, Napolitano, Alessandra, Land, Edward J, Barone, Vincenzo, d’Ischia, Marco

“…An unprecedented 5,6-dihydroxyindole macrocycle (4) featuring a rigid twisted backbone was obtained by biomimetic oxidative cross-coupling of the 2,2′-biindole…”
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The Mechanism of Suicide-Inactivation of Tyrosinase: A Substrate Structure Investigation by Land, Edward J., Ramsden, Christopher A., Riley, Patrick A.

“…Tyrosinase is a copper-containing mono-oxygenase, widely distributed in nature, able to catalyze the oxidation of both phenols and catechols to the…”
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Evidence Consistent with the Requirement of Cresolase Activity for Suicide Inactivation of Tyrosinase by Land, Edward J., Ramsden, Christopher A., Riley, Patrick A., Stratford, Michael R.L.

“…Tyrosinase is a mono-oxygenase with a dinuclear copper catalytic center which is able to catalyze both the ortho-hydroxylation of monophenols (cresolase…”
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Short-Lived Quinonoid Species from 5,6-Dihydroxyindole Dimers en Route to Eumelanin Polymers:  Integrated Chemical, Pulse Radiolytic, and Quantum Mechanical Investigation by Pezzella, Alessandro, Panzella, Lucia, Crescenzi, Orlando, Napolitano, Alessandra, Navaratman, Suppiah, Edge, Ruth, Land, Edward J, Barone, Vincenzo, d'Ischia, Marco

“…The transient species formed by oxidation of three dimers of 5,6-dihydroxyindole (1), a major building block of the natural biopolymer eumelanin, have been…”
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Lack of Visible Chromophore Development in the Pulse Radiolysis Oxidation of 5,6-Dihydroxyindole-2-carboxylic Acid Oligomers: DFT Investigation and Implications for Eumelanin Absorption Properties by Pezzella, Alessandro, Panzella, Lucia, Crescenzi, Orlando, Napolitano, Alessandra, Navaratnam, Suppiah, Edge, Ruth, Land, Edward J, Barone, Vincenzo, d’Ischia, Marco

“…The structural factors underlying the peculiar optical properties and visible chromophore of eumelanin biopolymers are largely uncharted. It is known that…”
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Potency of inhibition of human DNA topoisomerase I by flavones assessed through physicochemical parameters by Bensasson, René V., Zoete, Vincent, Jossang, Akino, Bodo, Bernard, Arimondo, Paola B., Land, Edward J.

“…DNA topoisomerases, enzymes involved in DNA replication and transcription, are known as targets for anticancer drugs. Among the various types of topoisomerase…”
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Investigation of the anomalous action of 5-hydroxyresorcinol on tyrosinase by Land, Edward J., Ramsden, Christopher A., Riley, Patrick A., Stratford, Michael R. L.

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Quinone chemistry and melanogenesis by Land, Edward J, Ramsden, Christopher A, Riley, Patrick A

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Chemical, Pulse Radiolysis and Density Functional Studies of a New, Labile 5,6-Indolequinone and Its Semiquinone by Pezzella, Alessandro, Crescenzi, Orlando, Natangelo, Anna, Panzella, Lucia, Napolitano, Alessandra, Navaratnam, Suppiah, Edge, Ruth, Land, Edward J, Barone, Vincenzo, d'Ischia, Marco

“…The chemical and spectroscopic characterization of 5,6-indolequinones and their semiquinones, key transient intermediates in the oxidative conversion of…”
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Dopamine quinone chemistry: a study of the influence of amide, amidine and guanidine substituents [-NH-CX-Y] on the mode of reaction by Land, Edward J, Perona, Almudena, Ramsden, Christopher A, Riley, Patrick A

“…The influence of N-substituents on the mode of reaction of ortho-quinones generated by oxidation of N-substituted dopamine derivatives has been studied…”
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Studies of carotenoid one-electron reduction radicals by Edge, Ruth, El-Agamey, Ali, Land, Edward J., Navaratnam, Suppiah, George Truscott, T.

“…The relative reduction potentials of a variety of carotenoids have been established by monitoring the reaction of carotenoid radical anion (CAR1 − ) with…”
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Evidence of the Indirect Formation of the Catecholic Intermediate Substrate Responsible for the Autoactivation Kinetics of Tyrosinase by Cooksey, Christopher J., Garratt, Peter J., Land, Edward J., Pavel, Stan, Ramsden, Christopher A., Riley, Patrick A., Smit, Nico P.M.

“…Tyrosinase (EC 1.14.18.1) exhibits unusual kinetic properties in the oxidation of monohydric phenol substrates consisting of a lag period that increases with…”
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Carotenoid Radical Anions and Their Protonated Derivatives by El-Agamey, Ali, Edge, Ruth, Navaratnam, Suppiah, Land, Edward J, Truscott, T. George

“…In this study, we report the protonation reactions for astaxanthin and canthaxanthin radical anions in methanol, alkaline methanol, and aqueous 2% Triton X-100…”
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Pulse radiolysis study of the interaction of retinoids with peroxyl radicals by Różanowska, Małgorzata, Cantrell, Ann, Edge, Ruth, Land, Edward J., Sarna, Tadeusz, Truscott, T. George

“…Vitamin A (retinol) and its derivatives—retinal and retinoic acid—are known for their ability to inhibit lipid peroxidation. Antioxidant actions of retinoids…”
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Relative One-Electron Reduction Potentials of Carotenoid Radical Cations and the Interactions of Carotenoids with the Vitamin E Radical Cation by Edge, Ruth, Land, Edward J, McGarvey, David, Mulroy, Louise, Truscott, T. George

“…Pulse radiolysis studies have been used to determine the electron-transfer rate constants between various pairs of carotenoids, one of which is present as the…”
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An MO study of regioselective amine addition to ortho-quinones relevant to melanogenesis by Land, Edward J., Ramsden, Christopher A., Riley, Patrick A.

“…Energy profiles for alternative intramolecular cyclisations of 4-(aminoalkyl)- ortho-quinones have been calculated using the AM1 method and ab initio energies…”
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