1
|
Watson WP, Munter T, Golding BT. The effect of vitamin B 12 on DNA adduction by styrene oxide, a genotoxic xenobiotic. Chem Biol Interact 2023; 382:110591. [PMID: 37302460 DOI: 10.1016/j.cbi.2023.110591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/25/2023] [Accepted: 05/31/2023] [Indexed: 06/13/2023]
Abstract
Vitamin B12 (cyano- or hydroxo-cobalamin) acts, via its coenzymes, methyl- and adenosyl-cobalamin, as a partner for enzymatic reactions in humans catalysed by methionine synthase and methylmalonyl-CoA mutase. As well as its association with pernicious anaemia, human B12 deficiency may also be a risk factor for neurological illnesses, heart disease and cancer. In the present work the effect of vitamin B12 (hydroxocobalamin) on the formation of DNA adducts by the epoxide phenyloxirane (styrene oxide), a genotoxic metabolite of phenylethene (styrene), has been studied using an in vitro model system. Styrene was converted to its major metabolite styrene oxide as a mixture of enantiomers using a microsomal fraction from the livers of Sprague-Dawley rats with concomitant inhibition of epoxide hydrolase. However, microsomal oxidation of styrene in the presence of vitamin B12 gave diastereoisomeric 2-hydroxy-2-phenylcobalamins. The quantitative formation of styrene oxide-DNA adducts was investigated using 2-deoxyguanosine or calf thymus DNA in the presence or absence of vitamin B12. Microsomal incubations containing either deoxyguanosine or DNA in the absence of vitamin B12 gave 2-amino-7-(2-hydroxy-1-phenylethyl)-1,7-dihydro-6H-purin-6-one [N7-(2-hydroxy-1-phenylethyl)-guanine], and 2-amino-7-(2-hydroxy-2-phenylethyl)-1,7-dihydro-6H-purin-6-one [N7-(2-hydroxy-2-phenylethyl)guanine] as the principal adducts. With deoxyguanosine the level of formation of guanine adducts was ca. 150 adducts/106 unmodified nucleoside. With DNA the adduct level was 36 pmol/mg DNA (ca. 1 adduct/0.83 × 105 nucleotides). Styrene oxide adducts from deoxyguanosine or DNA were not detected in microsomal incubations of styrene in the presence of vitamin B12. These results suggest that vitamin B12 could protect DNA against genotoxicity due to styrene oxide and other xenobiotic metabolites. However, this potential defence mechanism requires that the 2-hydroxyalkylcobalamins derived from epoxides are not 'anti-vitamins' and ideally liberate, and therefore, recycle vitamin B12. Otherwise, depletion of vitamin B12 leading to human deficiency could increase the risk of carcinogenesis initiated by genotoxic epoxides.
Collapse
Affiliation(s)
- William P Watson
- Syngenta Central Toxicology Laboratory, Alderley Park, Cheshire, SK10 4TJ, UK
| | - Tony Munter
- Syngenta Central Toxicology Laboratory, Alderley Park, Cheshire, SK10 4TJ, UK
| | - Bernard T Golding
- School of Natural and Environmental Sciences - Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| |
Collapse
|
2
|
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.
Collapse
Affiliation(s)
- Helder M Marques
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa.
| |
Collapse
|
3
|
DNA as an in vitro trapping agent for detection of bulky genotoxic metabolites. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1152:122276. [PMID: 32721860 DOI: 10.1016/j.jchromb.2020.122276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/17/2020] [Accepted: 07/15/2020] [Indexed: 11/20/2022]
Abstract
The instability of electrophilic reactive metabolites in in vitro metabolism studies makes their accurate analysis challenging. To stabilise the reactive compounds prior to their analysis, different trapping agents, such as thiols, amines and cob(I)alamin, have earlier been tested depending on the metabolites to be analysed and the type of study. In the present work, DNA is introduced as a trapping agent for measuring the formation of bulky electrophilic metabolites. Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon (PAH), was used as a model compound in a rat liver S9 metabolic system. Under physiological incubation conditions, B[a]P metabolises to diol epoxide (BPDE) metabolites which were trapped by DNA resulting in the formation of covalently bound DNA adducts. The methodology for analysis of these adducts included extraction of the DNA from the metabolic system, digestion of the DNA to yield nucleosides and analysis of the BPDE-adduct to deoxyguanosine (BPDE-dG) by liquid chromatography coupled to high resolution mass spectrometry (HRMS). The chromatographic conditions in combination with the high mass accuracy data (±3 ppm) was useful in resolving BPDE-dG in its protonated form from the complex set of ions present in the metabolic matrix. The method was validated in terms of sensitivity, specificity, accuracy, precision and recovery, and applied to provide a preliminary estimate of BPDE-dG levels from the metabolism of B[a]P in rat S9. The use of DNA as a trapping agent for in vitro metabolites has a potential to aid in cancer risk assessment procedure of PAHs, for instance, in inter-species comparison of metabolism to reactive metabolites and can be adapted for screening of genotoxic metabolites, e.g., from emerging environmental contaminants.
Collapse
|
4
|
Potrząsaj A, Ociepa M, Baka O, Spólnik G, Gryko D. Vitamin B12
Enables Consecutive Generation of Acyl and Alkyl Radicals from One Reagent. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901137] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Aleksandra Potrząsaj
- Institute of Organic Chemistry Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Michał Ociepa
- Institute of Organic Chemistry Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Oskar Baka
- Institute of Organic Chemistry Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Grzegorz Spólnik
- Institute of Organic Chemistry Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Dorota Gryko
- Institute of Organic Chemistry Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| |
Collapse
|
5
|
Tahara K, Pan L, Ono T, Hisaeda Y. Learning from B 12 enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis. Beilstein J Org Chem 2018; 14:2553-2567. [PMID: 30410616 PMCID: PMC6204771 DOI: 10.3762/bjoc.14.232] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 09/13/2018] [Indexed: 01/12/2023] Open
Abstract
Cobalamins (B12) play various important roles in vivo. Most B12-dependent enzymes are divided into three main subfamilies: adenosylcobalamin-dependent isomerases, methylcobalamin-dependent methyltransferases, and dehalogenases. Mimicking these B12 enzyme functions under non-enzymatic conditions offers good understanding of their elaborate reaction mechanisms. Furthermore, bio-inspiration offers a new approach to catalytic design for green and eco-friendly molecular transformations. As part of a study based on vitamin B12 derivatives including heptamethyl cobyrinate perchlorate, we describe biomimetic and bioinspired catalytic reactions with B12 enzyme functions. The reactions are classified according to the corresponding three B12 enzyme subfamilies, with a focus on our recent development on electrochemical and photochemical catalytic systems. Other important reactions are also described, with a focus on radical-involved reactions in terms of organic synthesis.
Collapse
Affiliation(s)
- Keishiro Tahara
- Department of Material Science, Graduate School of Material Science, University of Hyogo, 3-2-1, Kouto, Kamigori, Ako 678-1297, Japan
| | - Ling Pan
- Department of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
| | - Toshikazu Ono
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.,Center for Molecular Systems (CMS), Kyushu University, Fukuoka 819-0395, Japan.,PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Yoshio Hisaeda
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.,Center for Molecular Systems (CMS), Kyushu University, Fukuoka 819-0395, Japan
| |
Collapse
|
6
|
Motwani HV, Eriksson L, Göpfert L, Larsen K. Reaction kinetic studies for comparison of mutagenic potency between butadiene monoxide and glycidamide. Chem Biol Interact 2018; 288:57-64. [PMID: 29653098 DOI: 10.1016/j.cbi.2018.03.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/13/2018] [Accepted: 03/27/2018] [Indexed: 12/13/2022]
Abstract
DNA adducts can be formed from covalent binding of electrophilic reactive compounds to the nucleophilic N- and O-atoms of the biomolecule. The O-sites on DNA, with nucleophilic strength (n) of ca. 2, is recognized as a critical site for mutagenicity. Characterization of the reactivity of electrophilic compounds at the O-sites can be used to predict their mutagenic potency in relative terms. In the present study, reaction kinetic experiments were performed for butadiene monoxide (BM) in accordance with the Swain-Scott relation using model nucleophiles representing N- and O-sites on DNA, and earlier for glycidamide (GA) using a similar approach. The epoxide from the kinetic experiments was trapped by cob(I)alamin, resulting in formation of an alkylcobalamin which was analyzed by liquid chromatography tandem mass spectrometry. The Swain-Scott relationship was used to determine selectivity constant (s) of BM and GA as 0.86 and 1.0, respectively. The rate constant for the reaction at n of 2 was extrapolated to 0.023 and 0.038 M-1 h-1 for BM and GA, respectively, implying a higher mutagenic potency per dose unit of GA compared to BM. The reaction kinetic parameters associated with mutagenic potency were also estimated by a density functional theory approach, which were in accordance to the experimental determined values. These types of reaction kinetic measures could be useful in development of a chemical reactivity based prediction tool that could aid in reduction of animal experiments in cancer risk assessment procedures for relative mutagenicity.
Collapse
Affiliation(s)
- Hitesh V Motwani
- Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-10691 Stockholm, Sweden.
| | - Lars Eriksson
- Department of Materials and Environmental Chemistry, Stockholm University, SE-10691 Stockholm, Sweden
| | - Lisa Göpfert
- Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-10691 Stockholm, Sweden
| | - Kristian Larsen
- Department of Materials and Environmental Chemistry, Stockholm University, SE-10691 Stockholm, Sweden
| |
Collapse
|
7
|
Parallelogram based approach for in vivo dose estimation of genotoxic metabolites in humans with relevance to reduction of animal experiments. Sci Rep 2017; 7:17560. [PMID: 29242644 PMCID: PMC5730592 DOI: 10.1038/s41598-017-17692-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/29/2017] [Indexed: 12/14/2022] Open
Abstract
When employing metabolism studies of genotoxic compounds/metabolites and cancer tests for risk estimation, low exposure doses in humans are roughly extrapolated from high exposure doses in animals. An improvement is to measure the in vivo dose, i.e. area under concentration-time curve (AUC), of the causative genotoxic agent. In the present work, we propose and evaluate a parallelogram based approach for estimation of the AUC of genotoxic metabolites that incorporates in vitro metabolic data and existing knowledge from published in vivo data on hemoglobin (Hb) adduct levels, using glycidamide (GA) as a case study compound that is the genotoxic metabolite of acrylamide (AA). The estimated value of AUC of GA per AUC of AA from the parallelogram approach vs. that from Hb adduct levels measured in vivo were in good agreement; 0.087 vs. 0.23 in human and 1.4 vs. 0.53 in rat, respectively. The described parallelogram approach is simple, and can be useful to provide an approximate estimation of the AUC of metabolites in humans at low exposure levels for which sensitive methods for analyzing the metabolites are not available, as well as aid in reduction of animal experiments for metabolism studies that are to be used for cancer risk assessment.
Collapse
|
8
|
Dereven'kov IA, Ivlev PA, Bischin C, Salnikov DS, Silaghi-Dumitrescu R, Makarov SV, Koifman OI. Comparative studies of reaction of cobalamin (II) and cobinamide (II) with sulfur dioxide. J Biol Inorg Chem 2017; 22:969-975. [PMID: 28620693 DOI: 10.1007/s00775-017-1474-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 06/07/2017] [Indexed: 12/20/2022]
Abstract
The kinetics of reactions of cobalamin (II) and cobinamide (II) with sulfur dioxide was studied by UV-visible (UV-vis) spectroscopy. Reaction results in oxidation of Co(II) center and involves two aquated SO2 moieties. The final product is suggested to be complex Co(III)-S2O 4•- . The absence of corrin ring modifications during the reactions was proved.
Collapse
Affiliation(s)
- Ilia A Dereven'kov
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000, Ivanovo, Russia
| | - Pavel A Ivlev
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000, Ivanovo, Russia
| | - Cristina Bischin
- Department of Chemistry and Chemical Engineering, "Babes-Bolyai" University, Str. Arany Janos Nr. 11, 400028, Cluj-Napoca, Romania
| | - Denis S Salnikov
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000, Ivanovo, Russia.
| | - Radu Silaghi-Dumitrescu
- Department of Chemistry and Chemical Engineering, "Babes-Bolyai" University, Str. Arany Janos Nr. 11, 400028, Cluj-Napoca, Romania
| | - Sergei V Makarov
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000, Ivanovo, Russia
| | - Oscar I Koifman
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000, Ivanovo, Russia
| |
Collapse
|
9
|
Electronic and structural properties of Cob(I)alamin: Ramifications for B 12 -dependent processes. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2016.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
10
|
Dowling DP, Miles ZD, Köhrer C, Maiocco SJ, Elliott SJ, Bandarian V, Drennan CL. Molecular basis of cobalamin-dependent RNA modification. Nucleic Acids Res 2016; 44:9965-9976. [PMID: 27638883 PMCID: PMC5175355 DOI: 10.1093/nar/gkw806] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 08/30/2016] [Accepted: 09/03/2016] [Indexed: 12/22/2022] Open
Abstract
Queuosine (Q) was discovered in the wobble position of a transfer RNA (tRNA) 47 years ago, yet the final biosynthetic enzyme responsible for Q-maturation, epoxyqueuosine (oQ) reductase (QueG), was only recently identified. QueG is a cobalamin (Cbl)-dependent, [4Fe-4S] cluster-containing protein that produces the hypermodified nucleoside Q in situ on four tRNAs. To understand how QueG is able to perform epoxide reduction, an unprecedented reaction for a Cbl-dependent enzyme, we have determined a series of high resolution structures of QueG from Bacillus subtilis. Our structure of QueG bound to a tRNATyr anticodon stem loop shows how this enzyme uses a HEAT-like domain to recognize the appropriate anticodons and position the hypermodified nucleoside into the enzyme active site. We find Q bound directly above the Cbl, consistent with a reaction mechanism that involves the formation of a covalent Cbl-tRNA intermediate. Using protein film electrochemistry, we show that two [4Fe-4S] clusters adjacent to the Cbl have redox potentials in the range expected for Cbl reduction, suggesting how Cbl can be activated for nucleophilic attack on oQ. Together, these structural and electrochemical data inform our understanding of Cbl dependent nucleic acid modification.
Collapse
Affiliation(s)
- Daniel P Dowling
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zachary D Miles
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Caroline Köhrer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Sean J Elliott
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Vahe Bandarian
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Catherine L Drennan
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA .,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
11
|
Motwani HV, Törnqvist M. In vivo doses of butadiene epoxides as estimated from in vitro enzyme kinetics by using cob(I)alamin and measured hemoglobin adducts: An inter-species extrapolation approach. Toxicol Appl Pharmacol 2014; 281:276-84. [DOI: 10.1016/j.taap.2014.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/16/2014] [Accepted: 10/19/2014] [Indexed: 12/11/2022]
|
12
|
Dereven'kov IA, Salnikov DS, Makarov SV, Boss GR, Koifman OI. Kinetics and mechanism of oxidation of super-reduced cobalamin and cobinamide species by thiosulfate, sulfite and dithionite. Dalton Trans 2014; 42:15307-16. [PMID: 23999614 DOI: 10.1039/c3dt51714d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We studied the kinetics of reactions of cob(I)alamin and cob(I)inamide with thiosulfate, sulfite, and dithionite by UV-Visible (UV-Vis) and stopped-flow spectroscopy. We found that the two Co(I) species were oxidized by these sulfur-containing compounds to Co(II) forms: oxidation by excess thiosulfate leads to penta-coordinate complexes and oxidation by excess sulfite or dithionite leads to hexa-coordinate Co(II)-SO2(-) complexes. The net scheme involves transfer of three electrons in the case of oxidation by thiosulfate and one electron for oxidation by sulfite and dithionite. On the basis of kinetic data, the nature of the reactive oxidants was suggested, i.e., HS2O3(-) (for oxidation by thiosulfate), S2O5(2-), HSO3(-), and aquated SO2 (for oxidation by sulfite), and S2O4(2-) and SO2(-) (for oxidation by dithionite). No difference was observed in kinetics with cob(i)alamin or cob(i)inamide as reductants.
Collapse
Affiliation(s)
- Ilia A Dereven'kov
- State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000 Ivanovo, Russia.
| | | | | | | | | |
Collapse
|
13
|
Kornobis K, Ruud K, Kozlowski PM. Cob(I)alamin: insight into the nature of electronically excited states elucidated via quantum chemical computations and analysis of absorption, CD and MCD data. J Phys Chem A 2013; 117:863-76. [PMID: 23281629 DOI: 10.1021/jp310446c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The nature of electronically excited states of the super-reduced form of vitamin B(12) (i.e., cob(I)alamin or B(12s)), a ubiquitous B(12) intermediate, was investigated by performing quantum-chemical calculations within the time-dependent density functional theory (TD-DFT) framework and by establishing their correspondence to experimental data. Using response theory, the electronic absorption (Abs), circular dichroism (CD) and magnetic CD (MCD) spectra of cob(I)alamin were simulated and directly compared with experiment. Several issues have been taken into considerations while performing the TD-DFT calculations, such as strong dependence on the applied exchange-correlation (XC) functional or structural simplification imposed on the cob(I)alamin. In addition, the low-lying transitions were also validated by performing CASSCF/MC-XQDPT2 calculations. By comparing computational results with existing experimental data a new level of understanding of electronic excitations has been established at the molecular level. The present study extends and confirms conclusions reached for other cobalamins. In particular, the better performance of the BP86 functional, rather than hybrid-type, was observed in terms of the excitations associated with both Co d and corrin π localized transitions. In addition, the lowest energy band was associated with multiple metal-to-ligand charge transfer excitations as opposed to the commonly assumed view of a single π → π* transition followed by vibrational progression. Finally, the use of the full cob(I)alamin structure, instead of simplified molecular models, shed new light on the spectral analyses of cobalamin systems and revealed new challenges of this approach related to long-range charge transfer excitations involving side chains.
Collapse
Affiliation(s)
- Karina Kornobis
- Department of Chemistry, University of Louisville, 2320 South Brook Street, Louisville, Kentucky 40292, United States
| | | | | |
Collapse
|
14
|
Zhu W, Yuan Y, Zhou P, Zeng L, Wang H, Tang L, Guo B, Chen B. The expanding role of electrospray ionization mass spectrometry for probing reactive intermediates in solution. Molecules 2012; 17:11507-37. [PMID: 23018925 PMCID: PMC6268401 DOI: 10.3390/molecules171011507] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 08/29/2012] [Accepted: 09/05/2012] [Indexed: 12/31/2022] Open
Abstract
Within the past decade, electrospray ionization mass spectrometry (ESI-MS) has rapidly occupied a prominent position for liquid-phase mechanistic studies due to its intrinsic advantages allowing for efficient "fishing" (rapid, sensitive, specific and simultaneous detection/identification) of multiple intermediates and products directly from a "real-world" solution. In this review we attempt to offer a comprehensive overview of the ESI-MS-based methodologies and strategies developed up to date to study reactive species in reaction solutions. A full description of general issues involved with probing reacting species from complex (bio)chemical reaction systems is briefly covered, including the potential sources of reactive intermediate (metabolite) generation, analytical aspects and challenges, basic rudiments of ESI-MS and the state-of-the-art technology. The main purpose of the present review is to highlight the utility of ESI-MS and its expanding role in probing reactive intermediates from various reactions in solution, with special focus on current progress in ESI-MS-based approaches for improving throughput, testing reality and real-time detection by using newly developed MS instruments and emerging ionization sources (such as ambient ESI techniques). In addition, the limitations of modern ESI-MS in detecting intermediates in organic reactions is also discussed.
Collapse
Affiliation(s)
- Weitao Zhu
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Yu Yuan
- School of Pharmaceutical Sciences, Central South University, 172 Tongzipo Road, Changsha 410013, China;
| | - Peng Zhou
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Le Zeng
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Hua Wang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Ling Tang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Bin Guo
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Bo Chen
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| |
Collapse
|
15
|
Plymale NT, Dassanayake RS, Hassanin HA, Brasch NE. Kinetic and Mechanistic Studies on the Reactions of the Reduced Vitamin B12 Complex Cob(I)alamin with Nitrite and Nitrate. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100992] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
16
|
Motwani HV, Törnqvist M. Quantitative analysis by liquid chromatography–tandem mass spectrometry of glycidamide using the cob(I)alamin trapping method: Validation and application to in vitro metabolism of acrylamide. J Chromatogr A 2011; 1218:4389-94. [DOI: 10.1016/j.chroma.2011.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 02/22/2011] [Accepted: 05/09/2011] [Indexed: 11/29/2022]
|
17
|
Cob(I)alamin reacts with sucralose to afford an alkylcobalamin: Relevance to in vivo cobalamin and sucralose interaction. Food Chem Toxicol 2011; 49:750-7. [DOI: 10.1016/j.fct.2010.11.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 11/23/2010] [Accepted: 11/26/2010] [Indexed: 11/20/2022]
|
18
|
Kirman CR, Albertini RJ, Sweeney LM, Gargas ML. 1,3-Butadiene: I. Review of metabolism and the implications to human health risk assessment. Crit Rev Toxicol 2010; 40 Suppl 1:1-11. [PMID: 20868266 DOI: 10.3109/10408444.2010.507181] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
1,3-Butadiene (BD) is a multisite carcinogen in laboratory rodents following lifetime exposure, with mice demonstrating greater sensitivity than rats. In epidemiology studies of men in the styrene-butadiene rubber industry, leukemia mortality is associated with butadiene exposure, and this association is most pronounced for high-intensity BD exposures. Metabolism is an important determinant of BD carcinogenicity. BD is metabolized to several electrophilic intermediates, including epoxybutene (EB), diepoxybutane (DEB), and epoxybutane diol (EBD), which differ considerably in their genotoxic potency (DEB >> EB > EBD). Important species differences exist with respect to the formation of reactive metabolites and their subsequent detoxification, which underlie observed species differences in sensitivity to the carcinogenic effects of BD. The modes of action for human leukemia and for the observed solid tumors in rodents are both likely related to the genotoxic potencies for one or more of these metabolites. A number of factors related to metabolism can also contribute to nonlinearity in the dose-response relationship, including enzyme induction and inhibition, depletion of tissue glutathione, and saturation of oxidative metabolism. A quantitative risk assessment of BD needs to reflect these species differences and sources of nonlinearity if it is to reflect the current understanding of the disposition of BD.
Collapse
|