4390-05-0Relevant articles and documents
Characterization of a new enzyme oxidizing ω-amino group of aminocarboxyric acid, aminoalcohols and amines from Phialemonium sp. AIU 274
Isobe, Kimiyasu,Sasaki, Tomoko,Aigami, Yuusuke,Yamada, Miwa,Kishino, Shigenobu,Ogawa, Jun
, p. 89 - 95 (2013/10/22)
A new enzyme exhibiting oxidase activity for ω-aminocarboxylic acids, ω-aminoalcohols, monoamines and diamines was found from a newly isolated fungal strain, Phialemonium sp. AIU 274. The enzyme also oxidized aromatic amines, but not l- and d-amino acids. The Vmax/Km value for hexylamine was higher than those for 6-aminoalcohol and 6-aminhexanoic acid in the aliphatic C6 substrates. In the aliphatic amines, the higher Vmax/Km values were obtained by the longer carbon chain amines. Thus, the enzyme catalyzed oxidative deamination of the ω-amino group in a wide variety of the ω-amino compounds and preferred medium- and long-chain substrates. The oxidase with such broad substrate specificity was first reported here. The enzyme contained copper, and the enzyme activity was strongly inhibited by isoniazid, iproniazid and semicarbazide, but not by clorgyline and pargyline. The enzyme was composed of two identical subunits of 75 kDa.
Mn(III) oxidation of peptides: A mechanistic investigation of kinetic variations in hydrophobic-induced oxidation of tetrapeptides of elastin sequences
Srinivasa,Abiraj,Baba, A. Ramesha,Gowda, D. Channe
, p. 115 - 123 (2008/02/03)
Four tetrapeptide analogues of elastin sequences, glycyl-glycyl-alanyl- proline (GGAP), glycyl-glycyl-valyl-proline (GGVP), glycyl-glycyl-isoleucyl- proline (GGIP), and glycyl-glycyl-phenylalanyl-proline (GGFP) were synthesized, based on their increasing order of hydrophobicity, by a classical solution phase method and were characterized. These tetrapeptides (TETPs) were oxidized using Mn(OAc)3 in 25% acetic acid at 298 K, and the kinetics of the reaction was monitored spectrophotometrically at λmax == 400 nm. A first-order dependence of rate on each of [Mn(OAc)3], [OAc -], and substrate [TETP], an inverse order dependence on [H +], has been observed. The rate is independent of [Mn(II)]. However, an inverse order dependence on varying the dielectric constant using various percentages (v/v) of acetic acid has also been observed, and but addition of anions such as Cl- and ClO4- has insignificant effect on the rate. Activation parameters have been evaluated using the Arrhenius and Erying plots. The oxidation products were isolated and characterized. Based on the results obtained, a plausible mechanism involving [Mn(OAc)4]- has been proposed. An apparent correlation was noted between the rate of oxidation of these TETPs by Mn(III) in the presence of sulfate ions in sulfuric acid medium and Mn(OAc)3 in the acetic acid medium. The rate of oxidation with Mn(OAc)3 was observed to be slower than with the former. The rate of oxidation of GGFP was found to be higher than GGIP, GGVP, and GGAP, This may be due to the presence of an aromatic side chain and/or because of the increased hydrophobicity. The overall order of rate of oxidation of TETPs is GGFP > GGIP > GGVP > GGAP, which also represents an increasing order of their hydrophobicity.
Hydrogen Atom Transfer Oxidation of Primary and Secondary Alcoholates into Aldehydes and Ketones by Aromatic Halides in Liquid Ammonia. A New Electrochemically Induceable Reaction
Amatore, Christian,Badoz-Lambling, Janine,Bonnel-Huyghes, Claudine,Pinson, Jean,Saveant, Jean Michel,Thiebault, Andre
, p. 1979 - 1986 (2007/10/02)
It is possible to induce the oxidation of alcoholates into the corresponding carbonyl compounds by electrochemical reduction of aromatic halides in liquid ammonia, i.e., to electrochemically trigger the reaction ArX + >CH-O- -> ArH + >C=O + X-.H-Atom transfer from the acoholate to the aryl radical formed upon reduction of the aryl halide appears as the key step of the oxidation process.The ketyl anion radical thus formed can be oxidized into the parent carbonyl compound, remain electrochemically stable, or be reduced into the dianion depending upon the location of the two corresponding standard potentials toward the reduction potential of the aryl halide.Electricity consumption thus tends toward 0, 1, and 2 F/mol for the three cases, respectively.The reactions competing with H-atom transfer, thus lowering the efficiency of the electrochemical inducement of the oxidation process, are electron transfer to the aryl radical which occur at the electrode surface and/or in the solution.These will play the role of termination steps for the corresponding chain system involving homogeneous initiation of the reaction.The kinetic analysis of the competition between H-atom transfer and homogeneous or heterogeneous electron transfer allows a detailed investigation of the reaction mechanism by electrochemical techniques such as cyclic voltammetry.This also leads to the determination of the rate constants of H-atom transfer of the alcoholate-aryl radical couple.
