2880-58-2Relevant academic research and scientific papers
Peroxidase versus Peroxygenase Activity: Substrate Substituent Effects as Modulators of Enzyme Function in the Multifunctional Catalytic Globin Dehaloperoxidase
McGuire, Ashlyn H.,Carey, Leiah M.,De Serrano, Vesna,Dali, Safaa,Ghiladi, Reza A.
, p. 4455 - 4468 (2018)
The dehaloperoxidase-hemoglobin (DHP) from the terebellid polychaete Amphitrite ornata is a multifunctional hemoprotein that catalyzes the oxidation of a wide variety of substrates, including halo/nitrophenols, haloindoles, and pyrroles, via peroxidase and/or peroxygenase mechanisms. To probe whether substrate substituent effects can modulate enzyme activity in DHP, we investigated its reactiviy against a panel of o-guaiacol substrates given their presence (from native/halogenated and non-native/anthropogenic sources) in the benthic environment that A. ornata inhabits. Using biochemical assays supported by spectroscopic, spectrometric, and structural studies, DHP was found to catalyze the H2O2-dependent oxidative dehalogenation of 4-haloguaiacols (F, Cl, and Br) to 2-methoxybenzoquinone (2-MeOBQ). 18O labeling studies confirmed that O atom incorporation was derived exclusively from water, consistent with substrate oxidation via a peroxidase-based mechanism. The 2-MeOBQ product further reduced DHP to its oxyferrous state, providing a link between the substrate oxidation and O2 carrier functions of DHP. Nonnative substrates resulted in polymerization of the initial substrate with varying degrees of oxidation, with 2-MeOBQ identified as a minor product. When viewed alongside the reactivity of previously studied phenolic substrates, the results presented here show that simple substituent effects can serve as functional switches between peroxidase and peroxygenase activities in this multifunctional catalytic globin. More broadly, when recent findings on DHP activity with nitrophenols and azoles are included, the results presented here further demonstrate the breadth of heterocyclic compounds of anthropogenic origin that can potentially disrupt marine hemoglobins or function as environmental stressors, findings that may be important when assessing the environmental impact of these pollutants (and their metabolites) on aquatic systems.
The Crystal Structure of 2-Methoxy-1,4-benzoquinone: Molecular Recognition involving Intermolecular Dipole-Dipole- and C-H...O Hydrogen Bond Interactions
Keegstra, Erik M. D.,Spek, Anthony L.,Zwikker, Jan W.,Jenneskens, Leonardus W.
, p. 1633 - 1634 (1994)
In its crystal structure 2-methoxy-1,4-benzoquinone 2 is networked into a planar hexagonal pattern by intermolecular dipole-dipole- and extensive C-H...O hydrogen bond interactions leading to a graphite-like layer packing motif.
Regioselective synthesis of substituted pterocarpans and pterocarpenes. Lewis acid Ti(IV) promoted formal (3 + 2) cycloaddition reactions
Murugesh,Subburaj,Trivedi
, p. 2217 - 2228 (1996)
A synthesis of novel pterocarpans (8a-3, 10a-c and 11a-e) and pterocarpenes (7a-d and 9a-c) has been carried out. This method involves the Lewis acid Ti(IV) promoted formal (3 + 2) cycloaddition reaction of 2-alkoxy-1,4-benzoquinones (6a-c) with appropriately substituted 2H-chromenes (1a-b, 2a-b and 5) at -78°C.
Reactivity of a Ru(iii)-hydroxo complex in substrate oxidation in water
Ohzu, Shingo,Ishizuka, Tomoya,Kotani, Hiroaki,Kojima, Takahiko
, p. 15018 - 15021 (2014)
A mononuclear RuIII-OH complex oxidizes substrates such as hydroquinones in water through a pre-equilibrium process based on adduct formation by hydrogen bonding between the RuIII-OH complex and the substrates. The reaction mechanism switches from hydrogen atom transfer to electron transfer depending on the oxidation potential of substrates. This journal is
Catalytic conversion of lignin: Studies on oxidation of lignin model phenolic monomer over CoMCM-41 and CoMCM-48 catalysts
Sadual,Sahoo,Badamali
, p. 434 - 442 (2018)
The present study focussed on investigation of the potentiality of cobalt containing mesoporous material (M41S) as a robust heterogeneous catalyst for the oxidation of lignin model phenolic compound. Cobalt containing MCM-41 and MCM-48 were prepared under hydrothermal condition and characterized by various spectroscopic and analytical techniques. Formation of well ordered hexagonal and cubic mesopore structures of MCMs, containing cobalt in the silicate framework was inferred from XRD, TG-DTA and N2 adsorption-desorption studies. DR UV-visible spectral analysis revealed existence of Co(II) and Co(III) in the tetrahedral framework. The oxidative ability of CoMCMs were studied for the lignin model phenolic monomer, 1-(4-hydroxy-3-methoxyphenoxy)-ethanol, under mild conditions using environmentally benign H2O2 as the oxidant. The catalytic results showed that under optimum reaction conditions, apocynol undergoes selective oxidation yielding 2-methoxybenzoquinone and acetovanillone. CoMCM-41 was found to be more selective towards acetovanillone, on the contrary, CoMCM-48 was better catalyst for 2-methoxybenzoquinone yield.
Oxidative cleavage of C-C double bond in cinnamic acids with hydrogen peroxide catalysed by vanadium(v) oxide
Horvat, Monika,Iskra, Jernej
, p. 2073 - 2081 (2022/04/07)
We have developed a cheap, green, mild and environmentally friendly method for the selective cleavage of carbon-carbon double bonds with a 30% aqueous solution of hydrogen peroxide as the oxidant and vanadium(v) oxide as the catalyst. The selectivity of the oxidative cleavage of cinnamic acid derivatives 1 depends on the substituents and the solvent used (DME - MeOCH2CH2OMe, TFE - 2,2,2-trifluoroethanol or MeCN). In DME, p-hydroxy derivatives were selectively converted to benzaldehyde derivatives 2, in TFE, oxidative cleavage led to the formation of benzoquinone derivatives 4, while in MeCN, cinnamic acid derivatives were selectively converted to benzoic acid derivatives 3. Ferulic acid 1a was quantitatively and selectively converted to vanillin 2a in a 91% isolated yield on a gram scale. Dimeric difurandione 1a′ was isolated as an intermediate, which was confirmed by in situ ATR-IR spectroscopy, while the formation of diols or epoxides was not observed. The analogous styrene derivative, 4-vinylguaiacol 1e was also selectively converted to either vanillin 2a or 2-methoxyquinone 4a in a high yield. The green metric for the conversion of ferulic acid to vanillin by different methods was calculated and compared to our method, and showed that our method has better environmental parameters.
Aerobic Oxidation of Dihydroxyarenes Substrates Catalyzed by Polymer-Supported RuII-Pheox/Silica-Gel: A Beneficial Route for Purification of Industrial Water
Abu-Elfotoh, Abdel-Moneim
supporting information, p. 236 - 243 (2022/04/09)
A broad class of dihydroxyarenes were easily oxidized by aerobic oxygen to quinone products in excellent yields under the catalytic effect of polymer-supported RuII-Pheox/silica-gel catalyst. By using this combined catalyst, hydroquinone and catechol derivatives with electron-donating groups were easily oxidized by molecular oxygen to quinone products in 90% to >99% yield, while in the case of electron-withdrawing group, only 70% was obtained. The biologically useful 1,4-Naphthoqinone products were obtained in 83% to 90%. The catalyst was easily obtained and reused many times without a significant decrease in reactivity. Interestingly, a sample of industrial water contaminated with phenolic compounds was subjected to aerobic oxidation by using this catalyst, and the resultant quinones were detected within one day and the catalyst was removed and reused several times with different contami-nating samples with the same efficiency. Other catalytic oxidations by using this promising catalyst were investigated.
Organophotocatalytic Aerobic Oxygenation of Phenols in a Visible-Light Continuous-Flow Photoreactor
Wellauer, Jo?l,Miladinov, Dragan,Buchholz, Thomas,Schütz, Jan,Stemmler, René T.,Medlock, Jonathan A.,Bonrath, Werner,Sparr, Christof
supporting information, p. 9748 - 9752 (2021/05/27)
A mild photocatalytic phenol oxygenation enabled by a continuous-flow photoreactor using visible light and pressurized air is described herein. Products for wide-ranging applications, including the synthesis of vitamins, were obtained in high yields by precisely controlling principal process parameters. The reactor design permits low organophotocatalyst loadings to generate singlet oxygen. It is anticipated that the efficient aerobic phenol oxygenation to benzoquinones and p-quinols contributes to sustainable synthesis.
PHOTOOXIDATION OF PHENOLIC COMPOUNDS
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Page/Page column 17-18, (2021/11/26)
The present invention relates to the photooxidation of phenolic compounds to the respective quinoid compounds using methylene blue as photosensitizer in a solvent mixture of water and alcohols using light of the high wavelength range of the visible spectrum.
Benzoic acid resin (BAR): a heterogeneous redox organocatalyst for continuous flow synthesis of benzoquinones from β-O-4 lignin models
Dias, Kevin de Aquino,Pereira Junior, Marcus Vinicius Pinto,Andrade, Leandro Helgueira
supporting information, p. 2308 - 2316 (2021/04/07)
A polymer-bound organocatalyst for Baeyer-Villiger reaction and phenol oxidation under continuous flow conditions is described for the first time.BARhas revealed two catalytic activities that enabled the generation of a novel approach for the synthesis of benzoquinones from β-O-4 lignin models in a one-pot protocol. High catalytic activities (yields up to 98%), selectivities, recyclability and productivity were achieved.
