3131-54-2Relevant articles and documents
Hemo-acrylic polymers as catalyst for the oxidative dehalogenation of 2,4,6-trichlorophenol. Chloroperoxidase's mimic imprinting effects
Díaz-Díaz, Goretti,Blanco-López, M. Carmen,Lobo-Casta?ón, M. Jesús,Miranda-Ordieres, Arturo J.,Tu?ón-Blanco, Paulino
, p. 117 - 121 (2012)
Acrylic polymers with catalytic activity for the oxidative degradation of 2,4,6-trichlorophenol (TCP) were developed. In order to mimic the active site of chloroperoxidase (CPO), chloro-iron(III)-protoporphyrin IX was used as the catalytic centre, and methacrylamide (MA) and 4-vinylpyridine (VPY) were used as the monomers that build up the active sites. Taking as basis 3:1 (w/w) acid:basic aminoacidic composition of CPO, three MA:VPY combinations were tested: one keeping the same ratio (3:1) i.e. 25% VPY in the functional monomer mixture, one with lower content of the basic monomer (9:1) i.e. 10% VPY, and one with higher concentration of it (1:1) i.e. 50% VPY. Polymers synthesized with the lowest VPY content exhibited the highest catalytic efficiency, which was improved by the creation of specific TCP binding sites through molecular imprinting technology. In these way, synthetic enzymes with useful properties for analytical and bioremediation applications were obtained.
Mechanisms of Reduction of trans-Cyclohexane-1,2-diamine-NNN'N'-tetra-acetatomanganate(III) by Hydrazine, Hydroxylamine, and Substituted Benzene-1,2-diols
Arselli, Patrizia,Mentasti, Edoardo
, p. 689 - 696 (1983)
The kinetics and mechanism of reduction of trans-cyclohexane-1,2-diamine-NNN'N'-tetra-acetatomanganate(III), III(cdta)(H2O)>-, by hydrazine hydroxylamine, and a series of substituted benzene-1,2-diols C6H3(OH)2R (R=H, 4-Me, 4-CO2H, or 3-CO2H) have been investigated by the stopped-flow technique.Simple first-order dependence on MnIII complex and reductant concentrations has been observed for hydrazine, which shows a rate with +>-1 dependence.For hydroxylamine, complex kinetic dependences on reductant and hydrogen-ion concentration suggest a composite inner-sphere mechanism.Also, in the case of the diols an inner-sphere mechanism, through intermediate association, is proposed; for these substrates experimental rates, higher than those computed with the Marcus cross relation, and limiting kinetics are in agreement with the lability of the oxidizing complex.
Copper-Aβ Peptides and Oxidation of Catecholic Substrates: Reactivity and Endogenous Peptide Damage
Pirota, Valentina,Dell'Acqua, Simone,Monzani, Enrico,Nicolis, Stefania,Casella, Luigi
, p. 16964 - 16973 (2016)
The oxidative reactivity of copper complexes with Aβ peptides 1–16 and 1–28 (Aβ16 and Aβ28) against dopamine and related catechols under physiological conditions has been investigated in parallel with the competitive oxidative modification undergone by the peptides. It was found that both Aβ16 and Aβ28 markedly increase the oxidative reactivity of copper(II) towards the catechol compounds, up to a molar ratio of about 4:1 of peptide/copper(II). Copper redox cycling during the catalytic activity induces the competitive modification of the peptide at selected amino acid residues. The main modifications consist of oxidation of His13/14 to 2-oxohistidine and Phe19/20 to ortho-tyrosine, and the formation of a covalent His6-catechol adduct. Competition by the endogenous peptide is rather efficient, as approximately one peptide molecule is oxidized every 10 molecules of 4-methylcatechol.
Purification and antiradical properties of the structural unit of betalains
Gandia-Herrero, Fernando,Escribano, Josefa,Garcia-Carmona, Francisco
, p. 1030 - 1036 (2012)
Betalamic acid [4-(2-oxoethylidene)-1,2,3,4-tetrahydropyridine- 2,6-dicarboxylic acid] is a naturally occurring compound that is normally found condensed with amino acids, amines, cyclo-DOPA, and cyclo-DOPA derivatives to form the betalains. Betalains are
Photometric assay for polyphenol oxidase activity in olives, olive pastes, and virgin olive oils
Valgimigli, Luca,Sanjust, Enrico,Curreli, Nicoletta,Rinaldi, Augusto,Pedulli, Gian F.,Rescigno, Antonio
, p. 1245 - 1248 (2001)
A photometric method is proposed that allows the determination of phenolase activity in olive fruits, olive pastes, and virgin olive oil. The method can also be used to quantify partially purified phenolase from olives, and is based on the coupling betwee
Characterization of immobilized tyrosinase-an enzyme that is stable in organic solvent at 100 °C
Wu, Lidong,Rathi, Brijesh,Chen, Yi,Wu, Xiuhong,Liu, Huan,Li, Jincheng,Ming, Anjie,Han, Gang
, p. 39529 - 39535 (2018)
Tyrosinase is a copper-containing enzyme present in plant and animal tissues, which catalyzes the production of melanin and other pigments. In organic solvent, tyrosinase can convert N-acetyl-l-tyrosine ethyl ester (insoluble in aqueous) to a derivative o
Catechol Oxidase versus Tyrosinase Classification Revisited by Site-Directed Mutagenesis Studies
Prexler, Sarah M.,Frassek, Martin,Moerschbacher, Bruno M.,Dirks-Hofmeister, Mareike E.
, p. 8757 - 8761 (2019)
Catechol oxidases (COs) and tyrosinases (TYRs) are both polyphenol oxidases (PPOs) that catalyze the oxidation of ortho-diphenols to the corresponding quinones. By the official classification, only TYRs can also catalyze the hydroxylation of monophenols to ortho-diphenols. Researchers have been trying to find the molecular reason for the mono-/diphenolase specificity for decades. However, the hypotheses for the lack of monophenolase activity of plant COs are only based on crystal structures so far. To test these hypotheses, we performed site-directed mutagenesis studies and phylogenetic analyses with dandelion PPOs offering high phylogenetic diversity, the results of which refute the structure-based hypotheses. While plant PPOs of phylogenetic group 2 solely exhibit diphenolase activity, plant PPOs of phylogenetic group 1 unexpectedly also show monophenolase activity. This finding sheds new light upon the molecular basis for mono-/diphenol substrate specificity and challenges the current practice of generally naming plant PPOs as COs.
Differential activation of a latent polyphenol oxidase mediated by sodium dodecyl sulfate
Gandia-Herrero, Fernando,Jimenez-Atienzar, Mercedes,Cabanes, Juana,Garcia-Carmona, Francisco,Escribano, Josefa
, p. 6825 - 6830 (2005)
A kinetic study of the activity of soluble and membrane-bound latent polyphenol oxidase (PPO) extracted from beet root (Beta vulgaris) was carried out. For the first time, two types of behavior (hyperbolic and sigmoid) are reported in the same enzyme for
Aminomethylene-Phosphonate Analogue as a Cu(II) Chelator: Characterization and Application as an Inhibitor of Oxidation Induced by the Cu(II)-Prion Peptide Complex
Pariente Cohen, Natalie,Lo Presti, Eliana,Dell'Acqua, Simone,Jantz, Thomas,Shimon, Linda J. W.,Levy, Naomi,Nassir, Molhm,Elbaz, Lior,Casella, Luigi,Fischer, Bilha
, p. 8995 - 9003 (2019)
Recently, we reported on a series of aminomethylene-phosphonate (AMP) analogues, bearing one or two heterocyclic groups on the aminomethylene moiety, as promising Zn(II) chelators. Given the strong Zn(II) binding properties of these compounds, they may fi
Synthesis, structure, polyphenol oxidase mimicking and bactericidal activity of a zinc-schiff base complex
Mahato, Shreya,Meheta, Nishith,Kotakonda, Muddukrishnaiah,Joshi, Mayank,Shit, Madhusudan,Choudhury, Angshuman Roy,Biswas, Bhaskar
supporting information, (2020/12/13)
Focusing on the important biological functions of metallo-enzymes and metallo-therapeutics in living world, this research work demonstrates the synthesis, crystal structure, supramolecular architecture, 4-methylcatechol oxidation and bactericidal activity
The impact of an isoreticular expansion strategy on the performance of iodine catalysts supported in multivariate zirconium and aluminum metal-organic frameworks
Tahmouresilerd, Babak,Moody, Michael,Agogo, Louis,Cozzolino, Anthony F.
supporting information, p. 6445 - 6454 (2019/05/24)
Iodine functionalized variants of DUT-5 (Al) and UiO-67 (Zr) were prepared as expanded-pore analogues of MIL-53 (Al) and UiO-67 (Zr). They were prepared using a combination of multivariate and isorecticular expansion strategies. Multivariate MOFs with a 25% iodine-containing linker was chosen to achieve an ideal balance between a high density of catalytic sites and sufficient space for efficient diffusion. Changes to the oxidation potential of the catalyst as a result of the pore-expansion strategy led to a decrease in activity with electron rich substrates. On the other hand, these larger frameworks proved to be more efficient catalysts for substrates with higher oxidation potentials. Recyclability tests for these larger MOFs showed sustained catalytic activity over multiple recycles.
