Electrochemical multicomponent synthesis of 4-selanylpyrazoles under catalyst- and chemical-oxidant-free conditions

Green Chemistry, Journal Year: 2021, Volume and Issue: 23(11), P. 3950 - 3954

Published: Jan. 1, 2021

An electrochemical multicomponent reaction was established under catalyst-, chemical-oxidant-free and mild conditions, which provides an eco-friendly simple protocol for constructing 4-selanylpyrazoles from easily available raw materials with high yields.

Language: Английский

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Carbon Monoxide Poisoning: From Microbes to Therapeutics

Annual Review of Medicine, Journal Year: 2023, Volume and Issue: 75(1), P. 337 - 351

Published: Aug. 15, 2023

Carbon monoxide (CO) poisoning leads to 50,000–100,000 emergency room visits and 1,500–2,000 deaths each year in the United States alone. Even with treatment, survivors often suffer from long-term cardiac neurocognitive deficits, highlighting a clear unmet medical need for novel therapeutic strategies that reduce morbidity mortality associated CO poisoning. This review examines prevalence impact of pathophysiology humans highlights recent advances accelerate clearance mitigate toxicity. We focus on developments high-affinity molecules take advantage uniquely strong interaction between heme selectively bind sequester preclinical models. These scavengers, which employ heme-binding scaffolds ranging organic small hemoproteins derived potentially even microorganisms, show promise as field-deployable antidotes may rapidly improve outcomes acute

Language: Английский

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Four-component synthesis of 3-aminomethylated imidazoheterocycles in EtOH under catalyst-free, oxidant-free and mild conditions

Green Chemistry, Journal Year: 2021, Volume and Issue: 23(12), P. 4430 - 4434

Published: Jan. 1, 2021

The 3-aminomethylated imidazoheterocycles were efficiently synthesized in one-step via a four-component reaction of equimolar cheap and commercially available reactants at ambient temperature under catalyst-, oxidant-, base-free mild conditions.

Language: Английский

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External electrolyte-free electrochemical one-pot cascade synthesis of 4-thiocyanato-1H-pyrazoles

Chinese Chemical Letters, Journal Year: 2022, Volume and Issue: 34(2), P. 107640 - 107640

Published: June 30, 2022

Language: Английский

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Chemogenetic Evolution of a Peroxidase-like Artificial Metalloenzyme

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(9), P. 5079 - 5087

Published: April 13, 2021

Directed evolution has helped enzyme engineering to remarkable successes in the past. A main challenge directed is find most suitable starting point, that is, an allows maximum "evolvability". Consisting of a synthetic cofactor embedded protein scaffold, artificial metalloenzymes (ArMs) are reminiscent rough-hewn ancestral metalloproteins and thus could provide evolutionarily clean slate. Here, we report design ArM with peroxidase-like properties based on nitrobindin variant, NB4. After identifying metal cofactor, two rounds were sufficient elevate ArM's activity levels akin those some natural peroxidases (up kcat = 14.1 s–1 kcat/Km 52,800 M–1 s–1). substitution arginine distal environment (position 76) was key boost peroxidase activity. Molecular dynamics simulations reveal flexibility site NB4 scaffold absent wildtype which unrestricted movement catalytically important Arg76. In addition oxidation common redox mediators (ABTS, syringaldehyde, 2,6-dimethoxyphenol), proved efficient decolorization three recalcitrant dyes (indigo carmine, reactive blue 19, black 5) amenable several recycling.

Language: Английский

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Design and Engineering of an Efficient Peroxidase Using Myoglobin for Dye Decolorization and Lignin Bioconversion

International Journal of Molecular Sciences, Journal Year: 2021, Volume and Issue: 23(1), P. 413 - 413

Published: Dec. 30, 2021

The treatment of environmental pollutants such as synthetic dyes and lignin has received much attention, especially for biotechnological treatments using both native artificial metalloenzymes. In this study, we designed engineered an efficient peroxidase the O2 carrier myoglobin (Mb) a protein scaffold by four mutations (F43Y/T67R/P88W/F138W), which combines key structural features natural peroxidases presence conserved His-Arg pair Tyr/Trp residues close to heme active center. Kinetic studies revealed that quadruple mutant exhibits considerably enhanced activity, with catalytic efficiency (kcat/Km) comparable most enzyme, horseradish (HRP). Moreover, enzyme can effectively decolorize variety organic catalyze bioconversion lignin, Kraft model compound, guaiacylglycerol-β-guaiacyl ether (GGE). As analyzed HPLC ESI-MS, identified several products GGE, produced via bond cleavage followed dimerization or trimerization, illustrates mechanism bioconversion. This study indicates could be exploited decolorization textile wastewater contaminated various dyes, well produce more value-added products.

Language: Английский

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Recent Advancements for Enhanced Biocatalyst and Biotransformation

Molecular Biotechnology, Journal Year: 2025, Volume and Issue: unknown

Published: April 9, 2025

Language: Английский

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Oxidative dehalogenation of trichlorophenol catalyzed by a promiscuous artificial heme-enzyme

RSC Advances, Journal Year: 2022, Volume and Issue: 12(21), P. 12947 - 12956

Published: Jan. 1, 2022

The miniaturized metalloenzyme Fe(iii)-mimochrome VI*a (Fe(iii)-MC6*a) acts as an excellent biocatalyst in the H2O2-mediated oxidative dehalogenation of well-known pesticide and biocide 2,4,6-trichlorophenol (TCP). artificial enzyme can oxidize TCP with a catalytic efficiency (kcat/KTCPm = 150 000 mM-1 s-1) up to 1500-fold higher than most active natural horseradish peroxidase (HRP). UV-visible EPR spectroscopies were used provide indications mechanism. One equivalent H2O2 fully converts Fe(iii)-MC6*a into oxoferryl-porphyrin radical cation intermediate [(Fe(iv)[double bond, length m-dash]O)por˙+], similarly compound I (Cpd I). Addition Cpd rapidly leads formation corresponding quinone, while decays back ferric resting state absence substrate. data suggest mechanism involving two consecutive one-electron reactions. All results highlight value miniaturization strategy for development chemically stable, highly efficient metalloenzymes powerful catalysts degradation toxic pollutants.

Language: Английский

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CO bonding in hexa‐ and pentacoordinate carboxy‐neuroglobin: A quantum mechanics/molecular mechanics and local vibrational mode study

Journal of Computational Chemistry, Journal Year: 2022, Volume and Issue: 43(25), P. 1725 - 1746

Published: Aug. 15, 2022

Abstract We present a comprehensive investigation on the different role of CO in carboxyneuroglobin (1) as ligand heme group active site forming bond with iron and (2) dissociated from but still trapped inside site, focusing two specific orientations, one perpendicular to plane defined by distal histidine enzyme (form A) located parallel that B). Our study includes wild type carboxy‐neuroglobin nine known protein mutations. Considering interacting can adapt tautomeric forms possible orientations CO, total 36 systems were analyzed this study. Fully optimized geometries vibrational frequencies calculated at QM/MM level, followed local mode analysis, decode properties. The intrinsic strengths derived complemented NBO QTAIM data, reveal strength bond, hexacoordinate (where is group) pentacoordinate scenarios, dominated through space charge transfer between Fe, fine‐tuned electrostatic dispersion interactions side chain amino acids pocket. Suggestions are made advise how modifications influence molecular properties coordinated or which could serve fine‐tuning existing design new neuroglobin models FeC strengths.

Language: Английский

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Functional metalloenzymes based on myoglobin and neuroglobin that exploit covalent interactions

Journal of Inorganic Biochemistry, Journal Year: 2024, Volume and Issue: 257, P. 112595 - 112595

Published: May 7, 2024

Language: Английский

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