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.
A green method for the electroorganic synthesis of new 1,3-indandione derivatives
Moghaddam, Abdolmajid Bayandori,Ganjali, Mohammad Reza,Norouzi, Parviz,Latifi, Maryam
, p. 1391 - 1396 (2006)
This is an environmentally friendly method in the field of electroorganic reactions under controlled potential electrolysis, without toxic reagents at a carbon electrode in an undivided cell which involves the (EC) mechanism reaction and comprises two ste
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.
Synthesis and DNA interaction of ethylenediamine platinum(II) complexes linked to DNA intercalants
Duskova, Katerina,Sierra, Sara,Fernández, María-José,Gude, Lourdes,Lorente, Antonio
, p. 7112 - 7118 (2012)
A series of ethylenediamine platinum(II) complexes connected through semi-rigid chains of 1,2-bis(4-pyridyl)ethane to DNA intercalating subunits (naphthalene, anthracene or phenazine) has been synthesized, and their interactions with calf thymus (CT) DNA
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.
Enhanced enzymatic reaction of tyrosinase-immobilized polyacrylamide- (γ-cyclodextrin) membrane coated on a platinum disk electrode in acetonitrile
Nakamura, Toshio,Ji, Xueping,Endo, Kazuyoshi,Takano, Daisuke
, p. 506 - 507 (2007)
A functionalized stable film, polyacrylamide-(γ-cyclodextrin) (PAA-γ-CD), synthesized from polyacrylamide (PAA) and γ-cyclodextrin (γ-CD), was used to immobilize enzyme. The membrane containing γ-CD provided an excellent environment for enzymatic kinetics
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
On the development of NAD(P)H-sensitive fluorescent probes
Maidwell, Nicola L.,Reza Rezai,Roeschlaub, Carl A.,Sammes, Peter G.
, p. 1541 - 1546 (2000)
In contrast to current, multi-reagent assay systems, the development of a single reagent that can be used to assay NAD(P)H is described. The reagent eliminates the fluorophore 4-methylumbelliferone from a quinoxalinium adduct upon reduction and the chemistry of this process is described. The Royal Society of Chemistry.
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
Quinone-induced protein modifications: Kinetic preference for reaction of 1,2-benzoquinones with thiol groups in proteins
Li, Yuting,Jongberg, Sisse,Andersen, Mogens L.,Davies, Michael J.,Lund, Marianne N.
, p. 148 - 157 (2016)
Oxidation of polyphenols to quinones serves as an antioxidative mechanism, but the resulting quinones may induce damage to proteins as they react through a Michael addition with nucleophilic groups, such as thiols and amines to give protein adducts. In this study, rate constants for the reaction of 4-methylbenzoquinone (4MBQ) with proteins, thiol and amine compounds were determined under pseudo first-order conditions by UV-vis stopped-flow spectrophotometry. The chemical structures of the adducts were identified by LC-ESI-MS/MS. Proteins with free thiols were rapidly modified by 4MBQ with apparent second order rate constants, k2 of (3.1±0.2)×104 M-1 s-1 for bovine serum albumin (BSA) and (4.8±0.2)×103 M-1 s-1 for human serum albumin at pH 7.0. These values are at least 12-fold greater than that for α-lactalbumin (4.0±0.2)×102 M-1 s-1, which does not contain any free thiols. Reaction of Cys-34 of BSA with N-ethylmaleimide reduced the thiol concentration by ~59%, which resulted in a decrease in k2 by a similar percentage, consistent with rapid adduction at Cys-34. Reaction of 4MBQ with amines (Gly, Nα-acetyl-l-Lys, N?-acetyl-l-Lys and l-Lys) and the guanidine group of Nα-acetyl-l-Arg was at least 5×105 slower than with low-molecular-mass thiols (l-Cys, Nα-acetyl-l-Cys, glutathione). The thiol-quinone interactions formed colorless thiol-phenol products via an intermediate adduct, while the amine-quinone interactions generated colored amine-quinone products that require oxygen involvement. These data provide strong evidence for rapid modification of protein thiols by quinone species which may be of considerable significance for biological and food systems.
