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Shichijo K, Kametani Y, Shiota Y, Yoshizawa K, Fujitsuka M, Shimakoshi H. Effect of Macrocycles on the Photochemical and Electrochemical Properties of Cobalt-Dehydrocorrin Complex: Formation and Investigation of Co(I) Species. Inorg Chem 2023; 62:11785-11795. [PMID: 37307067 DOI: 10.1021/acs.inorgchem.3c00882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Co(II)-pyrocobester (P-Co(II)), a dehydrocorrin complex, was semisynthesized from vitamin B12 (cyanocobalamin), and its photochemical and electrochemical properties were investigated and compared to those of the cobester (C-Co(II)), the cobalt-corrin complex. The UV-vis absorptions of P-Co(II) in CH2Cl2, ascribed to the π-π* transition, were red-shifted compared to those of C-Co(II) due to the π-expansion of the macrocycle in the pyrocobester. The reversible redox couple of P-Co(II) was observed at E1/2 = -0.30 V vs Ag/AgCl in CH3CN, which was assigned to the Co(II)/Co(I) redox couple by UV-vis, ESR, and molecular orbital analysis. This redox couple was positively shifted by 0.28 V compared to that of C-Co(II). This is caused by the high electronegativity of the dehydrocorrin macrocycle, which was estimated by DFT calculations for the free-base ligands. The reactivity of the Co(I)-pyrocobester (P-Co(I)) was evaluated by the reaction with methyl iodide in CV and UV-vis to form a photosensitive Co(III)-CH3 complex (P-Co(III)-CH3). The properties of the excited state of P-Co(I), *Co(I), were also investigated by femtosecond transient absorption (TA) spectroscopy. The lifetime of *Co(I) was estimated to be 29 ps from the kinetic trace at 587 nm. The lifetime of *Co(I) became shorter in the presence of Ar-X, such as iodobenzonitrile (1a), bromobenzonitrile (1b), and chlorobenzonitrile (1c), and the rate constants of electron transfer (ET) between the *Co(I) and Ar-X were determined to be 2.9 × 1011 M-1 s-1, 4.9 × 1010 M-1 s-1, and 1.0 × 1010 M-1 s-1 for 1a, 1b, and 1c, respectively.
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Affiliation(s)
- Keita Shichijo
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Yohei Kametani
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Yoshihito Shiota
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Mamoru Fujitsuka
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Osaka 567-0047, Japan
| | - Hisashi Shimakoshi
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
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2
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Ghosh A, Conradie J. B12 and F430 models: Metal- versus ligand-centered redox in cobalt and nickel tetradehydrocorrin derivatives. J Inorg Biochem 2023; 243:112199. [PMID: 36996695 DOI: 10.1016/j.jinorgbio.2023.112199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 03/18/2023] [Indexed: 03/29/2023]
Abstract
DFT calculations with the well-tested OLYP and B3LYP* exchange-correlation functionals (along with D3 dispersion corrections and all-electron ZORA STO-TZ2P basis sets) and careful use of group theory have led to significant insights into the question of metal- versus ligand-centered redox in Co and Ni B,C-tetradehydrocorrin complexes. For the cationic complexes, both metals occur in their low-spin M(II) forms. In contrast, the charge-neutral states vary for the two metals: while the Co(I) and CoII-TDC•2- state are comparable in energy for cobalt, a low-spin NiII-TDC•2- state is clearly preferred for nickel. The latter behavior stands in sharp contrast to other corrinoids that reportedly stabilize a Ni(I) center.
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Affiliation(s)
- Abhik Ghosh
- Department of Chemistry, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
| | - Jeanet Conradie
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa.
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3
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Marques HM. The inorganic chemistry of the cobalt corrinoids - an update. J Inorg Biochem 2023; 242:112154. [PMID: 36871417 DOI: 10.1016/j.jinorgbio.2023.112154] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023]
Abstract
The inorganic chemistry of the cobalt corrinoids, derivatives of vitamin B12, is reviewed, with particular emphasis on equilibrium constants for, and kinetics of, their axial ligand substitution reactions. The role the corrin ligand plays in controlling and modifying the properties of the metal ion is emphasised. Other aspects of the chemistry of these compounds, including their structure, corrinoid complexes with metals other than cobalt, the redox chemistry of the cobalt corrinoids and their chemical redox reactions, and their photochemistry are discussed. Their role as catalysts in non-biological reactions and aspects of their organometallic chemistry are briefly mentioned. Particular mention is made of the role that computational methods - and especially DFT calculations - have played in developing our understanding of the inorganic chemistry of these compounds. A brief overview of the biological chemistry of the B12-dependent enzymes is also given for the reader's convenience.
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Affiliation(s)
- Helder M Marques
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa.
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4
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Deng WH, Liao RZ. Sequential C-H Methylation Catalyzed by the B 12 -Dependent SAM Enzyme TokK: Comprehensive Theoretical Study of Selectivities. Chemistry 2023; 29:e202202995. [PMID: 36321632 DOI: 10.1002/chem.202202995] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 12/14/2022]
Abstract
TokK is a B12 -dependent radical SAM enzyme involved in the biosynthesis of the β-lactam antibiotic asparenomycin A. It can catalyze three methylations on different sp3 -hybridized carbon positions to introduce an isopropyl side chain at the β-lactam ring of pantetheinylated carbapenem. Herein, we report a quantum chemical study of the reaction mechanism of TokK. A stepwise ''push-pull'' radical relay mechanism is proposed for each methylation: a 5'-deoxyadenosine radical first abstracts a hydrogen atom from the substrate in the active site, then methylcobalamin directionally donates a methyl group to the substrate. More importantly, calculations were able to uncover the origin of observed chemoselectivity and stereoselectivity for the first methylation and regioselectivity for the following two methylations. Further detailed distortion/interaction analysis can help to unravel the main factors controlling the selectivities. Our findings of sequential methylations by TokK could have profound implications for studying other B12 -dependent radical SAM enzymes.
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Affiliation(s)
- Wen-Hao Deng
- Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of Education Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica Hubei Key Laboratory of Materials Chemistry and Service Failure School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of Education Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica Hubei Key Laboratory of Materials Chemistry and Service Failure School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
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5
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Determination of the Chemical Stability of Cyanocobalamin in Medical Food by a Validated Immunoaffinity Column-Linked HPLC Method. J FOOD QUALITY 2022. [DOI: 10.1155/2022/1619936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Cyanocobalamin, which plays an essential role in the body, is a synthetic form used in medical food. This present study aimed to develop an HPLC analysis method for determination cyanocobalamin and investigate the stability of cyanocobalamin in medical food. Validation of the developed method for cyanocobalamin was evaluated with linearity, LOD, LOQ, and accuracy. The linearity of this method was calculated with a value of the coefficient of determination (R2) ≥ 0.999. LOD and LOQ were 0.165 and 0.499 μg/kg, respectively. The recovery of medical food matrixes for accuracy was more than 97.63%. The validated method was applied for determining cyanocobalamin from medical foods. The developed method was used to examine the additives for cyanocobalamin protection. Ferric chloride and sorbitol alleviated cyanocobalamin degradation from heat and ascorbic acid. Especially, sorbitol showed a superior protective effect during the medical food production process. Therefore, this study suggests that sorbitol is a sweetener additive that prevents cyanocobalamin degradation by heat and the food matrix in medical food processing.
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6
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Spataru T. The complete electronic structure and mechanism of the methionine synthase process as determined by the MCSCF method. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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7
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Methyl transfer reactions catalyzed by cobalamin-dependent enzymes: Insight from molecular docking. J Mol Graph Model 2020; 104:107831. [PMID: 33529932 DOI: 10.1016/j.jmgm.2020.107831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 11/22/2022]
Abstract
Methyl transfer reactions, mediated by methyltransferases (MeTrs), such as methionine synthase (MetH) or monomethylamine: CoM (MtmBC), constitute one of the most important classes of vitamin B12-dependent reactions. The challenge in exploring the catalytic function of MeTrs is related to their modular structure. From the crystallographic point of view, the structure of each subunit has been determined, but there is a lack of understanding of how each subunit interacts with each other. So far, theoretical studies of methyl group transfer were carried out for the structural models of the active site of each subunit. However, those studies do not include the effect of the enzymatic environment, which is crucial for a comprehensive understanding of enzyme-mediated methyl transfer reactions. Herein, to explore how two subunits interact with each other and how the methyl transfer reaction is catalyzed by MeTrs, molecular docking of the functional units of MetH and MtmBC was carried out. Along with the interactions of the functional units, the reaction coordinates, including the Co-C bond distance for methylation of cob(I)alamin (CoICbl) and the C-S bond distance in demethylation reaction of cob(III)alamin (CoIIICbl), were considered. The functional groups should be arranged so that there is an appropriate distance to transfer a methyl group and present results indicate that steric interactions can limit the number of potential arrangements. This calls into question the possibility of SN2-type mechanism previously proposed for MeTrs. Further, it leads to the conclusion that the methyl transfer reaction involves some spatial changes of modules suggesting an alternate radical-based pathway for MeTrs-mediated methyl transfer reactions. The calculations also showed that changes in torsion angles induce a change in reaction coordinates, namely Co-C and C-S bond distances, for the methylation and demethylation reactions catalyzed both by MetH and MtmBC.
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8
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Weinstain R, Slanina T, Kand D, Klán P. Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials. Chem Rev 2020; 120:13135-13272. [PMID: 33125209 PMCID: PMC7833475 DOI: 10.1021/acs.chemrev.0c00663] [Citation(s) in RCA: 261] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Indexed: 02/08/2023]
Abstract
Photoactivatable (alternatively, photoremovable, photoreleasable, or photocleavable) protecting groups (PPGs), also known as caged or photocaged compounds, are used to enable non-invasive spatiotemporal photochemical control over the release of species of interest. Recent years have seen the development of PPGs activatable by biologically and chemically benign visible and near-infrared (NIR) light. These long-wavelength-absorbing moieties expand the applicability of this powerful method and its accessibility to non-specialist users. This review comprehensively covers organic and transition metal-containing photoactivatable compounds (complexes) that absorb in the visible- and NIR-range to release various leaving groups and gasotransmitters (carbon monoxide, nitric oxide, and hydrogen sulfide). The text also covers visible- and NIR-light-induced photosensitized release using molecular sensitizers, quantum dots, and upconversion and second-harmonic nanoparticles, as well as release via photodynamic (photooxygenation by singlet oxygen) and photothermal effects. Release from photoactivatable polymers, micelles, vesicles, and photoswitches, along with the related emerging field of photopharmacology, is discussed at the end of the review.
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Affiliation(s)
- Roy Weinstain
- School
of Plant Sciences and Food Security, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 6997801, Israel
| | - Tomáš Slanina
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague, Czech Republic
| | - Dnyaneshwar Kand
- School
of Plant Sciences and Food Security, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 6997801, Israel
| | - Petr Klán
- Department
of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
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9
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Kieninger C, Wurst K, Podewitz M, Stanley M, Deery E, Lawrence AD, Liedl KR, Warren MJ, Kräutler B. Replacement of the Cobalt Center of Vitamin B
12
by Nickel: Nibalamin and Nibyric Acid Prepared from Metal‐Free B
12
Ligands Hydrogenobalamin and Hydrogenobyric Acid. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Christoph Kieninger
- Institute of Organic Chemistry University of Innsbruck 6020 Innsbruck Austria
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
| | - Klaus Wurst
- Institute of General Inorganic and Theoretical Chemistry University of Innsbruck 6020 Innsbruck Austria
| | - Maren Podewitz
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
- Institute of General Inorganic and Theoretical Chemistry University of Innsbruck 6020 Innsbruck Austria
| | - Maria Stanley
- School of Biosciences University of Kent Canterbury CT2 7NJ UK
| | - Evelyne Deery
- School of Biosciences University of Kent Canterbury CT2 7NJ UK
| | | | - Klaus R. Liedl
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
- Institute of General Inorganic and Theoretical Chemistry University of Innsbruck 6020 Innsbruck Austria
| | - Martin J. Warren
- School of Biosciences University of Kent Canterbury CT2 7NJ UK
- Quadram Institute Bioscience Norwich Science Park Norwich NR4 7UQ UK
| | - Bernhard Kräutler
- Institute of Organic Chemistry University of Innsbruck 6020 Innsbruck Austria
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
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10
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Kieninger C, Wurst K, Podewitz M, Stanley M, Deery E, Lawrence AD, Liedl KR, Warren MJ, Kräutler B. Replacement of the Cobalt Center of Vitamin B 12 by Nickel: Nibalamin and Nibyric Acid Prepared from Metal-Free B 12 Ligands Hydrogenobalamin and Hydrogenobyric Acid. Angew Chem Int Ed Engl 2020; 59:20129-20136. [PMID: 32686888 PMCID: PMC7693184 DOI: 10.1002/anie.202008407] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Indexed: 12/18/2022]
Abstract
The (formal) replacement of Co in cobalamin (Cbl) by NiII generates nibalamin (Nibl), a new transition-metal analogue of vitamin B12 . Described here is Nibl, synthesized by incorporation of a NiII ion into the metal-free B12 ligand hydrogenobalamin (Hbl), itself prepared from hydrogenobyric acid (Hby). The related NiII corrin nibyric acid (Niby) was similarly synthesized from Hby, the metal-free cobyric acid ligand. The solution structures of Hbl, and Niby and Nibl, were characterized by spectroscopic studies. Hbl features two inner protons bound at N2 and N4 of the corrin ligand, as discovered in Hby. X-ray analysis of Niby shows the structural adaptation of the corrin ligand to NiII ions and the coordination behavior of NiII . The diamagnetic Niby and Nibl, and corresponding isoelectronic CoI corrins, were deduced to be isostructural. Nibl is a structural mimic of four-coordinate base-off Cbls, as verified by its ability to act as a strong inhibitor of bacterial adenosyltransferase.
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Affiliation(s)
- Christoph Kieninger
- Institute of Organic ChemistryUniversity of Innsbruck6020InnsbruckAustria
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
| | - Klaus Wurst
- Institute of GeneralInorganic and Theoretical ChemistryUniversity of Innsbruck6020InnsbruckAustria
| | - Maren Podewitz
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
- Institute of GeneralInorganic and Theoretical ChemistryUniversity of Innsbruck6020InnsbruckAustria
| | - Maria Stanley
- School of BiosciencesUniversity of KentCanterburyCT2 7NJUK
| | - Evelyne Deery
- School of BiosciencesUniversity of KentCanterburyCT2 7NJUK
| | | | - Klaus R. Liedl
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
- Institute of GeneralInorganic and Theoretical ChemistryUniversity of Innsbruck6020InnsbruckAustria
| | - Martin J. Warren
- School of BiosciencesUniversity of KentCanterburyCT2 7NJUK
- Quadram Institute BioscienceNorwich Science ParkNorwichNR4 7UQUK
| | - Bernhard Kräutler
- Institute of Organic ChemistryUniversity of Innsbruck6020InnsbruckAustria
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
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11
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Grimm C, Lazzarotto M, Pompei S, Schichler J, Richter N, Farnberger JE, Fuchs M, Kroutil W. Oxygen-Free Regioselective Biocatalytic Demethylation of Methyl-phenyl Ethers via Methyltransfer Employing Veratrol- O-demethylase. ACS Catal 2020; 10:10375-10380. [PMID: 32974079 PMCID: PMC7506938 DOI: 10.1021/acscatal.0c02790] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/17/2020] [Indexed: 11/28/2022]
Abstract
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The cleavage of aryl
methyl ethers is a common reaction in chemistry requiring rather harsh
conditions; consequently, it is prone to undesired reactions and lacks
regioselectivity. Nevertheless, O-demethylation of
aryl methyl ethers is a tool to valorize natural and pharmaceutical
compounds by deprotecting reactive hydroxyl moieties. Various oxidative
enzymes are known to catalyze this reaction at the expense of molecular
oxygen, which may lead in the case of phenols/catechols to undesired
side reactions (e.g., oxidation, polymerization). Here an oxygen-independent
demethylation via methyl transfer is presented employing a cobalamin-dependent
veratrol-O-demethylase (vdmB). The biocatalytic demethylation
transforms a variety of aryl methyl ethers with two functional methoxy
moieties either in 1,2-position or in 1,3-position. Biocatalytic reactions
enabled, for instance, the regioselective monodemethylation of substituted
3,4-dimethoxy phenol as well as the monodemethylation of 1,3,5-trimethoxybenzene.
The methyltransferase vdmB was also successfully applied for the regioselective
demethylation of natural compounds such as papaverine and rac-yatein. The approach presented here represents an alternative
to chemical and enzymatic demethylation concepts and allows performing
regioselective demethylation in the absence of oxygen under mild conditions,
representing a valuable extension of the synthetic repertoire to modify
pharmaceuticals and diversify natural products.
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Affiliation(s)
- Christopher Grimm
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstraße 28, 8010 Graz, Austria
| | - Mattia Lazzarotto
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstraße 28, 8010 Graz, Austria
| | - Simona Pompei
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstraße 28, 8010 Graz, Austria
| | - Johanna Schichler
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstraße 28, 8010 Graz, Austria
| | - Nina Richter
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria, c/o Institute of Chemistry, Heinrichstraße 28, 8010 Graz, Austria
| | - Judith E. Farnberger
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstraße 28, 8010 Graz, Austria
- ACIB GmbH, Petersgasse 14, 8010 Graz, Austria, c/o Institute of Chemistry, Heinrichstraße 28, 8010 Graz, Austria
| | - Michael Fuchs
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstraße 28, 8010 Graz, Austria
| | - Wolfgang Kroutil
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstraße 28, 8010 Graz, Austria
- Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
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12
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Kumar M, Francisco JS. Evidence of the Elusive Gold-Induced Non-classical Hydrogen Bonding in Aqueous Environments. J Am Chem Soc 2020; 142:6001-6006. [PMID: 32126169 DOI: 10.1021/jacs.9b05493] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The ability of a gold ion to act as a proton acceptor in hydrogen bonding continues to remain an open question. Heavy-atom effects and secondary competitive interactions in gold complexes make it challenging to precisely establish the identity of gold-ion-induced hydrogen bonding via experimental techniques. In such situations, computational chemistry may play an important role. Herein we have performed Born-Oppenheimer molecular dynamics simulations to study the behavior of [Au(CH3)2)]- in bulk and interfacial aqueous environments. The simulation results suggest that the [Au(CH3)2)]- complex forms one and two gold-ion-induced hydrogen bonds with the water molecules in interfacial and bulk environments, respectively. The calculated probabilities of key hydrogen-bonded configurations of [Au(CH3)2)]-, combined distribution functions, and diffusion coefficients further support this unusual hydrogen-bonding interaction. In summary, the present results suggest that gold-ion-induced hydrogen bonding in an actual solvent environment may be feasible. These results will improve our understanding about the role of weak interactions in transition metal complexes and, thus, will have implications in catalysis and supramolecular assemblies.
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Affiliation(s)
- Manoj Kumar
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Joseph S Francisco
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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13
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Elucidating the mechanism of cob(I)alamin mediated methylation reactions by alkyl halides: SN2 or radical mechanism? J Catal 2019. [DOI: 10.1016/j.jcat.2019.06.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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McCue AC, Moreau WM, Shell TA. Visible Light-Induced Radical Mediated DNA Damage. Photochem Photobiol 2018; 94:545-551. [PMID: 29377197 DOI: 10.1111/php.12890] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/18/2017] [Indexed: 12/31/2022]
Abstract
Light-responsive compounds have been used to manipulate biological systems with spatial and temporal control of the event of interest. Illumination of alkylcobalamins with green light (>500 nm) produces carbon-centered radicals, which have been demonstrated to effectively cause DNA damage. Molecules that cause DNA and RNA strand scission are useful for studying polynucleotide structure and the binding of small molecules and proteins to polynucleotides. Most molecules that cause DNA damage in a light-dependent manner require high energy, short wavelength ultraviolet light, which is readily absorbed by nucleotide bases causing damage to the polynucleotides. Therefore, using alkylcobalamins is advantageous for causing strand scission of polynucleotides, because they are activated by light wavelengths that are not absorbed by nucleotide bases. Green-light illumination of methylcobalamin effectively causes DNA strand scission based on gel mobility assays. This cleavage is due to the generation of carbon-centered radicals based on the results of a radical trapping study. In addition, synthesis of an alkylcobalamin with a DNA binding moiety, spermine, improves DNA cleavage efficacy by an order of magnitude in comparison with methylcobalamin.
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Affiliation(s)
- Amelia C McCue
- Department of Chemistry, Saint Anselm College, Manchester, NH
| | | | - Thomas A Shell
- Department of Chemistry and Biochemistry, Norwich University, Northfield, VT
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15
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16
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Ji L, Wang C, Ji S, Kepp KP, Paneth P. Mechanism of Cobalamin-Mediated Reductive Dehalogenation of Chloroethylenes. ACS Catal 2017. [DOI: 10.1021/acscatal.7b00540] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Li Ji
- College
of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Chenchen Wang
- College
of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Shujing Ji
- College
of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Kasper P. Kepp
- DTU
Chemistry, Technical University of Denmark, Building 206, Kgs. Lyngby DK-2800, Denmark
| | - Piotr Paneth
- Institute
of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
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