127-17-3Relevant articles and documents
Fluoromethylglyoxal: Synthesis and Glyoxalase I Catalyzed Product Partitioning via a Presumed Enediol Intermediate
Kozarich, John W.,Chari, Ravi V.J.,Wu, John C.,Lawrence, Timothy L.
, p. 4593 - 4595 (1981)
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Lohmann,Meyerhof
, p. 62 (1934)
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Ikawa,Snell
, p. 4900 (1954)
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Immobilization of thermotolerant intracellular enzymes on functionalized nanoporous activated carbon and application to degradation of an endocrine disruptor: kinetics, isotherm and thermodynamics studies
Saranya,Ranjitha,Sekaran
, p. 66239 - 66259 (2015)
A bacterium, Serratia marcescens capable of degrading the endocrine disruptor, 2-nitrophloroglucinol (NPG) was isolated from tannery wastewater contaminated soil. The mixed intracellular enzymes (MICE) produced from S. marcescens were extracted and characterized. The functionalized nanoporous activated carbon matrix (FNAC) was prepared to immobilize MICE. The optimum conditions for the immobilization of MICE on FNAC were found to be time, 2.5 h; pH, 7.0; temperature, 40°C; concentration of MICE, 4 mg; particle size of FNAC, 300 μm and mass of FNAC, 1 g. The FNAC materials before and after immobilization of MICE were characterized using scanning electron microscopy, Fourier transform-infrared spectrophotometry and an X-ray diffractometer. The thermal behaviour of the free and the immobilized MICE was studied using thermogravimetric analysis. The immobilization of MICE on FNAC obeyed the Freundlich model and the immobilization process followed a pseudo second order kinetic model. MICE-FNAC matrix was used to degrade NPG in aqueous solution. The degradation of NPG by MICE-FNAC was optimum at contact time, 3 h; pH, 7.0; temperature, 40°C; concentration of NPG, 20 μM and agitation speed, 70 rpm. The degradation of NPG was found to be enhanced in the presence of Zn2+, Cu2+, Ca2+ and V3+ ions. The degradation of NPG by MICE-FNAC was studied using UV-visible, fluorescence and FTIR spectroscopy. The degradation of NPG by MICE-FNAC was confirmed using HPLC, NMR and GC-MS spectroscopy.
Crystal structure of D-serine dehydratase from Escherichia coli
Urusova, Darya V.,Isupov, Michail N.,Antonyuk, Svetlana,Kachalova, Galina S.,Obmolova, Galina,Vagin, Alexei A.,Lebedev, Andrey A.,Burenkov, Gleb P.,Dauter, Zbigniew,Bartunik, Hans D.,Lamzin, Victor S.,Melik-Adamyan, William R.,Mueller, Thomas D.,Schnackerz, Klaus D.
, p. 422 - 432 (2012)
D-Serine dehydratase from Escherichia coli is a member of the β-family (fold-type II) of the pyridoxal 5′-phosphate-dependent enzymes, catalyzing the conversion of D-serine to pyruvate and ammonia. The crystal structure of monomeric D-serine dehydratase has been solved to 1.97 A-resolution for an orthorhombic data set by molecular replacement. In addition, the structure was refined in a monoclinic data set to 1.55 A resolution. The structure of DSD reveals a larger pyridoxal 5′-phosphate- binding domain and a smaller domain. The active site of DSD is very similar to those of the other members of the β-family. Lys118 forms the Schiff base to PLP, the cofactor phosphate group is liganded to a tetraglycine cluster Gly279-Gly283, and the 3-hydroxyl group of PLP is liganded to Asn170 and N1 to Thr424, respectively. In the closed conformation the movement of the small domain blocks the entrance to active site of DSD. The domain movement plays an important role in the formation of the substrate recognition site and the catalysis of the enzyme. Modeling of D-serine into the active site of DSD suggests that the hydroxyl group of D-serine is coordinated to the carboxyl group of Asp238. The carboxyl oxygen of D-serine is coordinated to the hydroxyl group of Ser167 and the amide group of Leu171 (O1), whereas the O2 of the carboxyl group of D-serine is hydrogen-bonded to the hydroxyl group of Ser167 and the amide group of Thr168. A catalytic mechanism very similar to that proposed for L-serine dehydratase is discussed.
Oxidation of lactic acid by water soluble (Colloidal) manganese dioxide
Khan, Zaheer,Raju,Akram, Mohd,Kabir-Ud-Din
, p. 359 - 366 (2004)
Spectrophotometric method has been used to characterize water-soluble colloidal manganese dioxide obtained by the redox reaction between sodium thiosulphate and potassium permanganate in neutral aqueous medium which shows a single peak in the visible region with λmax = 425 nm. The kinetics of the oxidation of lactic acid by colloidal manganese dioxide (oxidant) has been investigated spectrophotometrically under pseudo-first-order conditions of excess lactic acid. The rate of the noncatalytic reaction pathway was slow which increased with increasing lactic acid concentration. The reaction was first-order with respect to [oxidant] as well as [lactic acid]. In presence of manganase(II) and fluoride ions, the noncatalytic path disappeared completely while the oxidation rate of autocatalytic path increased and decreased, respectively with increasing [Mn(II)] and [F-]. A mechanistic scheme in conformity with the observed kinetics has been proposed with the rate-law: v = -d[MnO2]/dt = κ1κ2[MnO2] [H+][lactic acid]T/ ([H+] Ka)(κ_1 + ≤2)
A Convenient Electrochemical Synthesis of α-Oxoacids
Pokhodenko, Vitaly D.,Koshechko, Vjacheslav G.,Titov, Vladimir E.,Lopushanskaja, Victorija A.
, p. 3277 - 3278 (1995)
The possibility of obtaining aliphatic and aromatic-α-oxoacids via the direct electrochemical carboxylation of acetyl and benzoyl chlorides has been shown for the first time.
Ciusa
, (1937)
Mechanism of the Cl-atom-initiated Oxidation of Acetone and Hydroxyacetone in Air
Jenkin, Michael E.,Cox, Richard A.,Emrich, Martin,Moortgat, Geert K.
, p. 2983 - 2991 (1993)
The products of the Cl-atom-initiated oxidation of acetone and hydroxyacetone (CH3COCH2OH) in O2-N2 mixtures at 700 Torr and 298 K have been identified using long-path-length FTIR spectroscopy and long-path-length UV-visible diode array spectroscopy.The oxidation of acetone yields methyl glyoxal (CH3COCHO), HCHO, CO, CO2, CH3COOH, CH3OH, HCOOH and O3 as identifiable products.The data have been analysed, utilising the results of a kinetic study of the oxidation of acetone in air.The mechanism of the oxidation proceeds initially via the production of acetonylperoxy radicals (CH3COCH2O2) which are removed by their self-reaction (3), and reaction with other peroxy radicals produced by the subsequent chemistry: 2CH3COCH2O2 --> 2CH3COCH2O + O2 (3a), --> CH3COCHO + CH3COCH2OH + O2 (3b).The thermal decomposition of CH3COCH2O radicals produced in channel (3a) into CH3CO radicals and HCHO, is shown to predominate over the alternative reaction with O2, under the conditions of these experiments: CH3COCH2O + M --> CH3CO + HCHO + M (12), CH3COCH2O + O2 --> CH3COCHO + HO2 (13).Measurements of the yields of HCHO and CH3COCHO are consistent with the operation of both channels of reaction (3) and allow certain conclusions to be drawn concerning the reactions of CH3COCH2O2 with CH3O2 and CH3C(O)O2.The only detected primary organic product of the oxidation of CH3COCH2OH is CH3COCHO, formed with a yield of (100 +/- 5)percent by the following reaction sequence: Cl + CH3COCH2OH --> HCl + CH3COCHOH (4), CH3COCHOH + O2 --> CH3COCHO + HO2 (5).The concentration-time dependence of a range of secondary organic products, formed in the system was also measured.Identifiable products are CO, CO2, CH3COOH, HCHO, CH3OH, HCOOH and pyruvic acid (CH3COCOOH).These results are consistent with the presence of the CH3COCH(OH)O2 radical, formed as an intermediate in reaction (5): CH3COCH(OH)O2 CH3COCHO +HO2 (5 ).
Keto-enol equilibria in the pyruvic acid system: Determination of the Keto-enol equilibrium constants of pyruvic acid and pyruvate anion and the acidity constant of pyruvate enol in aqueous solution
Chiang,Kresge,Pruszynski
, p. 3103 - 3107 (1992)
Keto-enol equilibrium constants for the pyruvic acid system in aqueous solution at 25°C were determined by Meyer halogen titration and also by another method that evaluates these constants as ratios of enolization to ketonization rate constants, KE = kE/kK. Measurements by each method were made in both acidic and basic solution, and enol required for the ketonization rate measurements was supplied by hydrolysis of a silyl derivative and also by an equilibrated DMSO solution in which the enol content is greater than it is in water. The various methods gave nicely consistent results, which nevertheless differed between acidic and basic solutions, in accord with the different states of ionization of pyruvic acid in the two media; the values obtained were pKE = 3.21 for pyruvic acid in the carboxylic acid form and pKE = 5.03 for the pyruvate ion. The latter gives a free energy change for the ketonization of pyruvate enol that is 47% of the free energy liberated by the hydrolysis of the high-energy molecule, phosphoenolpyruvate; this shows that nearly half of the high energy content of this molecule resides in its masked enol function. An acidity constant for ionization of the enol hydroxyl group of pyruvate enol, pKaE = 11.55, was also determined, and this, when combined with pKE for this species, gives pKaK = 16.58 as the acidity constant of the pyruvate ion ionizing as a carbon acid.
Residue N84 of Yeast Cystathionine β-Synthase is a Determinant of Reaction Specificity
Lodha, Pratik H.,Hopwood, Emily M.S.,Manders, Adrienne L.,Aitken, Susan M.
, p. 1424 - 1431 (2010)
Cystathionine β-synthase (CBS) catalyzes the pyridoxal 5'-phosphate (PLP)-dependent condensation of l-serine and l-homocysteine to form l-cystathionine in the first step of the reverse transsulfuration pathway. Residue N84 of yeast CBS (yCBS), predicted to form a hydrogen bond with the hydroxyl moiety of the PLP cofactor, was mutated to alanine, aspartate and histidine. The truncated form of yCBS (ytCBS, residues 1-353) was employed in this study to eliminate any effects of the C-terminal, regulatory domain. The kcat/Kml-Ser of the N84A, N84D and N84H mutants for the β-replacement reaction is reduced by a factor of 230, 11000 and 640, respectively. Fluorescence resonance energy transfer between tryptophan residue(s) of the enzyme and the PLP cofactor, observed in the wild-type enzyme and N84A mutant, is altered in N84H and absent in N84D. PLP saturation values of 73%, 30% and 67% were observed for the alanine, aspartate and histidine mutants, respectively, compared to 98% for the wild-type enzyme. A marginal β-elimination activity was detected for N84D (kcat/Kml-Ser = 0.23 ± 0.02 M-1 s-1) and N84H (kcat/Kml-Ser = 0.34 ± 0.06 M-1 s-1), in contrast with wild-type ytCBS and the N84A mutant, which do not catalyze this reaction. The ytCBS-N84D enzyme is also inactivated upon incubation with l-serine, via an aminoacrylate-mediated mechanism. These results demonstrate that residue N84 is essential in maintaining the orientation of the pyridine ring of the PLP cofactor and the equilibrium between the open and closed conformations of the active site.
Photocatalytic reversible amination of α-keto acids on a ZnS surface: Implications for the prebiotic metabolism
Wang, Wei,Li, Qiliang,Yang, Bin,Liu, Xiaoyang,Yang, Yanqiang,Su, Wenhui
, p. 2146 - 2148 (2012)
We report the enzyme-like reversible amination of four intermediates pertinent to the reductive tricarboxylic acid cycle on a photo-irradiated surface of mineral sphalerite (ZnS). Given its prevalence in the waters of early Earth, we suggest that the mineral-based photochemistry might have catalyzed the homeostasis of prebiotic metabolic systems.
Muntz
, p. 663 (1947)
Rate constants for the reactions of methyl vinyl ketone, methacrolein, methacrylic acid, and acrylic acid with ozone
Neeb, Peter,Kolloff, Antje,Koch, Stephan,Moortgat, Geert K.
, p. 769 - 776 (1998)
Rate constants for the reaction of ozone with methylvinyl ketone (H2C=CHC(O)CH3), methacrolein (H2C=C(CH3)CHO), methacrylic acid (H2C=C(CH3)C(O)OH), and acrylic acid (H2C=CHC(O)OH) were measured at room temperature (296 ± 2 K) in the presence of a sufficient amount of cyclohexane to scavenge OH-radicals. Results from pseudo-first-order experiments in the presence of excess ozone were found not to be consistent with relative rate measurements. It appeared that the formation of the so-called Criegee-intermediates leads to an enhanced decrease in the concentration of the two organic acids investigated. It is shown that the presence of formic acid, which is known to react efficiently with Criegee-intermediates, diminishes the observed removal rate of the organic acids. The rate constant for the reaction of ozone with the unsaturated carbonyl compounds methylvinyl ketone and methacrolein was found not to be influenced by the addition of formic acid. Rate constants for the reaction of ozone determined in the presence of excess formic acid are (in cm3 molecule-1 s-1): methylvinyl ketone (5.4 ± 0.6) × 10-18; methacrolein (1.3 ± 0.14) × 10-18; methacrylic acid (4.1 ± 0.4) × 10-18; and acrylic acid (0.65 ± 0.13) × 10-18. Results are found to be consistent with the Criegee mechanism of the gas-phase ozonolysis.
Novel substrate specificity of designer 3-isopropylmalate dehydrogenase derived from Thermus thermophilus HB8
Fujita, Masaaki,Tamegai, Hideyuki,Eguchi, Tadashi,Kakinuma, Katsumi
, p. 2695 - 2700 (2001)
Redesigning of an enzyme for a new catalytic reaction and modified substrate specificity was exploited with 3-isopropylmalate dehydrogenase (IPMDH). Point-mutation on Gly-89, which is not in the catalytic site but near it, was done by changing it to Ala, Ser, Val, and Pro, and all the mutations changed the substrate specificity. The mutant enzymes showed higher catalytic efficiency (kcat/Km) than the native IPMDH when malate was used as a substrate instead of 3-isopropylmalate. More interestingly, an additional insertion of Gly between Gly-89 and Leu-90 significantly altered the substrate-specificity, although the overall catalytic activity was decreased. Particularly, this mutant turned out to efficiently accept D-lactic acid, which was not accepted as a substrate by wild-type IPMDH at all. These results demonstrate the opportunity for creating novel enzymes by modification of amino acid residues that do not directly participate in catalysis, or by insertion of additional residues.
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Hamilton,Revesz
, p. 2069 (1966)
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Photoinitiated synthesis of self-assembled vesicles
Griffith, Elizabeth C.,Rapf, Rebecca J.,Shoemaker, Richard K.,Carpenter, Barry K.,Vaida, Veronica
, p. 3784 - 3787 (2014)
The aqueous photochemistry of 2-oxooctanoic acid (a single-tailed surfactant) results in the synthesis of a double-tailed surfactant product followed by spontaneous self-assembly into vesicles. The photochemical mechanism is detailed here, and the reaction products are identified using mass spectrometry. Then, the self-assembled vesicles are characterized using dynamic light scattering, fluorescence microscopy, and NMR. Further, their stability over time and in the presence of MgCl2 salt is demonstrated. This work contributes to membrane evolution through the provision of a prebiotic route for the synthesis of plausible membrane components and subsequent self-assembly of a primitive enclosure.
Biosynthesis of Rhizocticins, Antifungal Phosphonate Oligopeptides Produced by Bacillus subtilis ATCC6633
Borisova, Svetlana A.,Circello, Benjamin T.,Zhang, Jun Kai,van der Donk, Wilfred A.,Metcalf, William W.
, p. 28 - 37 (2010)
Rhizocticins are phosphonate oligopeptide antibiotics containing the C-terminal nonproteinogenic amino acid (Z)-l-2-amino-5-phosphono-3-pentenoic acid (APPA). Here we report the identification and characterization of the rhizocticin biosynthetic gene cluster (rhi) in Bacillus subtilis ATCC6633. Rhizocticin B was heterologously produced in the nonproducer strain Bacillus subtilis 168. A biosynthetic pathway is proposed on the basis of bioinformatics analysis of the rhi genes. One of the steps during the biosynthesis of APPA is an unusual aldol reaction between phosphonoacetaldehyde and oxaloacetate catalyzed by an aldolase homolog RhiG. Recombinant RhiG was prepared, and the product of an in vitro enzymatic conversion was characterized. Access to this intermediate allows for biochemical characterization of subsequent steps in the pathway.
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Evans,Leermakers
, p. 1840 (1968)
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Oxidative dehydrogenation of lactic acid to pyruvic acid over Pb-Pt bimetallic supported on carbon materials
Zhang, Chen,Wang, Tao,Ding, Yunjie
, p. 59 - 65 (2017)
Various carbon materials, including activated carbon, flake graphite, carbon black and multiwall carbon nanotubes, were adopted as supports for lead-promoted platinum catalysts in the investigation of aqueous-phase oxidative dehydrogenation of lactic acid to produce pyruvic acid. Among them, the nanoscale 3Pb-1Pt/carbon black catalyst showed the highest TOF (769?h?1) and yielded 60% pyruvic acid within 20?min under mild conditions. N2adsorption, Raman spectroscopy, thermogravimetry, SEM, TEM and XPS were performed to investigate their different structures, graphitization degrees, metal particle sizes and surface oxidation states. Under the current conditions, smaller support particle size is essential for the enhanced lactic acid transformation rate by favoring the diffusion of reactants; less graphitic structure of catalyst is also beneficial by improving metal particle dispersion and facilitating the exposure of metals.
A simple and sensitive detection of glutamic-pyruvic transaminase activity based on fluorescence quenching of bovine serum albumin
Chen, Miao,Rong, Liya,Chen, Xiaoqing
, p. 103557 - 103562 (2015)
It is well known that Cu(ii) can coordinate with l-alanine (Cu-Ala), which can be destroyed through the addition of glutamic-pyruvic transaminase (GPT) since GPT can effectively catalyze the conversion of l-alanine into keto-acetic acid. As a result, the free Cu(ii) ion can combine with bovine serum albumin (BSA) and in turn quench the fluorescence of BSA. In this context, a simple and sensitive GPT activity detection via fluorescence quenching method has been developed. The fluorescence intensity of the system shows a linear relationship with the GPT concentration in the range of 5 and 400 U L-1 with a detection limit down to 3 U L-1 (S/N = 3). Avoiding any labels or complicated operations, this cost-effective and convenient method holds the potential for the rapid diagnosis of GPT-related diseases.
Enzymatic synthesis of pyruvic acid from acetaldehyde and carbon dioxide
Miyazaki,Shibue,Ogino,Nakamura,Maeda
, p. 1800 - 1801 (2001)
A new enzymatic synthesis of pyruvic acid from acetaldehyde and carbon dioxide has been developed.
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Boeeseken,Jakobs
, p. 811 (1936)
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Plattner,Clauson-Kaas
, p. 195 (1945)
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Brockmann,Stier
, p. 413 (1948)
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Utilizing in situ spectroscopic tools to monitor ketal deprotection processes
Ralbovsky, Nicole M.,Lomont, Justin P.,Ruccolo, Serge,Konietzko, Janelle,McHugh, Patrick M.,Wang, Sheng-Ching,Mangion, Ian,Smith, Joseph P.
, (2021/12/08)
The use of protection groups to shield a functional group during a synthesis is employed throughout many reactions and organic syntheses. The role of a protection group can be vital to the success of a reaction, as well as increase reaction yield and selectivity. Although much work has been done to investigate the addition of a protection group, the removal of the protection group is just as important – however, there is a lack of methods employed within the literature for monitoring the removal of a protection group in real time. In this work, the process of removing, or deprotecting, a ketal protecting group is investigated. Process analytical technology tools are incorporated for in situ analysis of the deprotection reaction of a small molecule model compound. Specifically, Raman spectroscopy and Fourier transform infrared spectroscopy show that characteristic bands can be used to track the decrease of the reactant and the increase of the expected products over time. To the best of our knowledge, this is the first report of process analytical technology being used to monitor a ketal deprotection reaction in real time. This information can be capitalized on in the future for understanding and optimizing pharmaceutically-relevant deprotection processes and downstream reactions.
The facet-regulated oxidative dehydrogenation of lactic acid to pyruvic acid on α-Fe2O3
Yin, Chunyu,Li, Xinli,Dai, Yunsheng,Chen, Zhi,Yang, Dingfeng,Liu, Ruixue,Zou, Weixin,Tang, Congming,Dong, Lin
supporting information, p. 328 - 332 (2021/01/29)
We propose a highly active α-Fe2O3 catalyst for the oxidative dehydrogenation of lactic acid to value-added pyruvic acid in air. The activity is determined by the utilized crystal face, due to the different adsorption energies of lactic acid molecules on different exposed planes. Furthermore, Fe sites show more preferential adsorption than crystal O sites.
Novel peptidomimetic peptide deformylase (PDF) inhibitors of Mycobacterium tuberculosis
Gokhale, Kunal M.,Telvekar, Vikas N.
, p. 148 - 156 (2020/08/26)
Emergence of MDR-TB and XDR-TB led to the failure of available anti-tubercular drugs. In order to explore, identify and develop new anti-tubercular drugs, novel peptidomimetic series of Mtb–peptide deformylase (PDF) inhibitors was designed and synthesized. In vitro antimycobacterial potential of compounds was established by screening of compounds against Mycobacterium tuberculosis H37Rv strain using MABA. Among them, ester series of compounds 4a, 4b, 4c, 4d, and 4e were found most active, with compound 4c being highly active and exhibiting minimum inhibitory concentration of 6.25?μg/ml against M.?tb H37Rv strain. Additionally, the compounds were docked to determine the probable binding interactions and understand the mechanism of action of most active molecules on Mtb-peptide deformylase (PDF), which is involved in the mycobacterium protein synthesis.
