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Toma M, Zubčić G, Lapić J, Djaković S, Šakić D, Vrček V. Ferrocenoyl-adenines: substituent effects on regioselective acylation. Beilstein J Org Chem 2022; 18:1270-1277. [PMID: 36225728 PMCID: PMC9520867 DOI: 10.3762/bjoc.18.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/09/2022] [Indexed: 11/23/2022] Open
Abstract
A series of N6-substituted adenine–ferrocene conjugates was prepared and the reaction mechanism underlying the synthesis was explored. The SN2-like reaction between ferrocenoyl chloride and adenine anions is a regioselective process in which the product ratio (N7/N9-ferrocenoyl isomers) is governed by the steric property of the substituent at the N6-position. Steric effects were evaluated by using Charton (empirical) and Sterimol (computational) parameters. The bulky substituents may shield the proximal N7 region of space, which prevents the approach of an electrophile towards the N7 atom. As a consequence, the formation of N7-isomer is a kinetically less feasible process, i.e., the corresponding transition state structure increases in relative energy (compared to the formation of the N9-isomer). In cases where the steric hindrance is negligible, the electronic effect of the N6-substituent is prevailing. That was supported by calculations of Fukui functions and molecular orbital coefficients. Both descriptors indicated that the N7 atom was more nucleophilic than its N9-counterpart in all adenine anion derivatives. We demonstrated that selected substituents may shift the acylation of purines from a regioselective to a regiospecific mode.
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Affiliation(s)
- Mateja Toma
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovačića 1, 10000 Zagreb, Croatia
| | - Gabrijel Zubčić
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovačića 1, 10000 Zagreb, Croatia
| | - Jasmina Lapić
- Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Senka Djaković
- Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Davor Šakić
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovačića 1, 10000 Zagreb, Croatia
| | - Valerije Vrček
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovačića 1, 10000 Zagreb, Croatia
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2
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Hornung JE, Weinrich T, Göbel MW. Directed Crosslinking of RNA by Glutathione‐Triggered PNA‐Quinone‐Methide‐Conjugates. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jan-Erik Hornung
- Goethe-Universitat Frankfurt am Main Institut für Organische Chemie und Chemische Biologie GERMANY
| | - Timo Weinrich
- Goethe-Universitat Frankfurt am Main Institut für Organische Chemie und Chemische Biologie GERMANY
| | - Michael W. Göbel
- Goethe-Universität Frankfurt Institut für Organische Chemie und Chemi Max-von-Laue-Str. 7 60438 Frankfurt am Main GERMANY
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3
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Hornung JE, Hellwig N, Göbel MW. Peptide Nucleic Acid Conjugates of Quinone Methide Precursors Alkylate Ribonucleic Acid after Activation with Light. Bioconjug Chem 2020; 31:639-645. [PMID: 31904221 DOI: 10.1021/acs.bioconjchem.9b00796] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Quinone methide precursors 2 and 3 were protected with a photoreactive 2-nitrobenzyl group and conjugated to peptide nucleic acids (PNA) using a Huisgen click reaction. After brief irradiation at 365 nm, cross-linking with complementary RNA strands started and was analyzed with an ALFexpress sequencer. When this method was used, the gel temperature had a major influence on apparent rates. Quinone methides are known to form transient as well as stable bonds with nucleotides. Although both were detected at 25 °C, analysis at 57 °C only recorded the stable types of cross-links, suggesting much slower alkylation kinetics. Linker 11 allowed us to attach quinone methides to internal positions of the PNA/RNA duplex and to capture a model of miR-20a with good efficiency.
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Sun Y, Tsai M, Zhou W, Lu W, Liu J. Reaction Kinetics, Product Branching, and Potential Energy Surfaces of 1O 2-Induced 9-Methylguanine-Lysine Cross-Linking: A Combined Mass Spectrometry, Spectroscopy, and Computational Study. J Phys Chem B 2019; 123:10410-10423. [PMID: 31718186 DOI: 10.1021/acs.jpcb.9b08796] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a kinetics and mechanistic study on the 1O2 oxidation of 9-methylguanine (9MG) and the cross-linking of the oxidized intermediate 2-amino-9-methyl-9H-purine-6,8-dione (9MOGOX) with Nα-acetyl-lysine-methyl ester (abbreviated as LysNH2) in aqueous solutions of different pH. Experimental measurements include the determination of product branching ratios and reaction kinetics using mass spectrometry and absorption spectroscopy, and the characterization of product structures by employing collision-induced dissociation. Strong pH dependence was revealed for both 9MG oxidation and the addition of nucleophiles (water and LysNH2) at the C5 position of 9MOGOX. The 1O2 oxidation rate constant of 9MG was determined to be 3.6 × 107 M-1·s-1 at pH 10.0 and 0.3 × 107 M-1·s-1 at pH 7.0, both of which were measured in the presence of 15 mM LysNH2. The ωB97XD density functional theory coupled with various basis sets and the SMD implicit solvation model was used to explore the reaction potential energy surfaces for the 1O2 oxidation of 9MG and the formation of C5-water and C5-LysNH2 adducts of 9MOGOX. Computational results have shed light on reaction pathways and product structures for the different ionization states of the reactants. The present work has confirmed that the initial 1O2 addition represents the rate-limiting step for the oxidative transformations of 9MG. All of the downstream steps are exothermic with respect to the starting reactants. The C5-cross-linking of 9MOGOX with LysNH2 significantly suppressed the formation of spiroiminodihydantoin (9MSp) resulting from the C5-water addition. The latter became dominant only at the low concentration (∼1 mM) of LysNH2.
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Affiliation(s)
- Yan Sun
- Department of Chemistry and Biochemistry , Queens College of the City University of New York , 65-30 Kissena Blvd. , Queens , New York 11367 , United States.,Ph.D. Program in Chemistry , The Graduate Center of the City University of New York , 365 5th Avenue , New York , New York 10016 , United States
| | - Midas Tsai
- Department of Natural Sciences , LaGuardia Community College , 31-10 Thomson Avenue , Long Island City , New York 11101 , United States
| | - Wenjing Zhou
- Department of Chemistry and Biochemistry , Queens College of the City University of New York , 65-30 Kissena Blvd. , Queens , New York 11367 , United States
| | - Wenchao Lu
- Department of Chemistry and Biochemistry , Queens College of the City University of New York , 65-30 Kissena Blvd. , Queens , New York 11367 , United States.,Ph.D. Program in Chemistry , The Graduate Center of the City University of New York , 365 5th Avenue , New York , New York 10016 , United States
| | - Jianbo Liu
- Department of Chemistry and Biochemistry , Queens College of the City University of New York , 65-30 Kissena Blvd. , Queens , New York 11367 , United States.,Ph.D. Program in Chemistry , The Graduate Center of the City University of New York , 365 5th Avenue , New York , New York 10016 , United States
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Naumczuk B, Bocian W, Sitkowski J, Kawęcki R, Kozerski L. Solvent-dependent regioselectivity of 2′-deoxyadenosine alkylation by 9-aminomethyl derivatives of SN38. NEW J CHEM 2019. [DOI: 10.1039/c9nj04828f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The investigated compounds in DMSO solution unexpectedly alkylate the N9 nitrogen of 2′-deoxyadenosine, whereas the N6 nitrogen atom is alkylated in water solution.
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Affiliation(s)
- B. Naumczuk
- National Medicines Institute
- Chełmska 30/34
- Poland
- Institute of Organic Chemistry
- Polish Academy of Sciences
| | - W. Bocian
- National Medicines Institute
- Chełmska 30/34
- Poland
| | - J. Sitkowski
- National Medicines Institute
- Chełmska 30/34
- Poland
- Institute of Organic Chemistry
- Polish Academy of Sciences
| | - R. Kawęcki
- University of Natural Sciences and Humanities
- Faculty of Science
- 3 Maja 54
- Poland
| | - L. Kozerski
- National Medicines Institute
- Chełmska 30/34
- Poland
- Institute of Organic Chemistry
- Polish Academy of Sciences
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6
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Naumczuk B, Kawęcki R, Bocian W, Bednarek E, Sitkowski J, Kozerski L. Regioselective alkylation reaction of the 2′-deoxyctidine with 9-aminomethyl derivatives of SN38. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.08.096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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7
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Ramesh M, Bharatam PV. Formation of a Toxic Quinoneimine Metabolite from Diclofenac: A Quantum Chemical Study. Drug Metab Lett 2018; 13:64-76. [PMID: 30210009 DOI: 10.2174/1872312812666180913120736] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 08/27/2018] [Accepted: 08/27/2018] [Indexed: 01/26/2023]
Abstract
BACKGROUND Diclofenac is a non-steroidal antiinflammatory drug. It is predominantly metabolized by CYP2C9. 4'-hydroxydiclofenac and its quinoneimine are the metabolites of diclofenac. However, few numbers of serious cases of idiosyncratic hepatotoxicity due to diclofenac metabolism were reported. The formation of the quinoneimine metabolite was found to be responsible for this idiosyncratic toxicity. Quinoneimine is an over-oxidized metabolite of diclofenac. METHOD In this work, computational studies were conducted to detail the formation of a quinoneimine metabolite from diclofenac. Further, the idiosyncratic toxicity of quinoneimine due to its reactivity was also investigated by quantum chemical analysis. RESULTS & CONCLUSION The results demonstrate the possibility of formation of quinoneimine metabolite due to various factors that are involved in the metabolism of diclofenac. The present study may provide the structural in-sights during the drug development processes to avoid the metabolism directed idiosyncratic toxicity.
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Affiliation(s)
- Muthusamy Ramesh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar (Mohali)-160 062, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar (Mohali)-160 062, India
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8
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Škalamera Đ, Antol I, Mlinarić-Majerski K, Vančik H, Phillips DL, Ma J, Basarić N. Ultrafast Adiabatic Photodehydration of 2-Hydroxymethylphenol and the Formation of Quinone Methide. Chemistry 2018; 24:9426-9435. [PMID: 29677402 DOI: 10.1002/chem.201801543] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Indexed: 12/13/2022]
Abstract
The photochemical reactivity of 2-hydroxymethylphenol (1) was investigated experimentally by photochemistry under cryogenic conditions, by detecting reactive intermediates by IR spectroscopy, and by using nanosecond and femtosecond transient absorption spectroscopic methods in solution at room temperature. In addition, theoretical studies were performed to facilitate the interpretation of the experimental results and also to simulate the reaction pathway to obtain a better understanding of the reaction mechanism. The main finding of this work is that photodehydration of 1 takes place in an ultrafast adiabatic photochemical reaction without any clear intermediate, delivering quinone methide (QM) in the excited state. Upon photoexcitation to a higher vibrational level of the singlet excited state, 1 undergoes vibrational relaxation leading to two photochemical pathways, one by which synchronous elimination of H2 O gives QM 2 in its S1 state and the other by which homolytic cleavage of the phenolic O-H bond produces a phenoxyl radical (S0 ). Both are ultrafast processes that occur within a picosecond. The excited state of QM 2 (S1 ) probably deactivates to S0 through a conical intersection to give QM 2 (S0 ), which subsequently delivers benzoxete 4. Elucidation of the reaction mechanisms for the photodehydration of phenols by which QMs are formed is important to tune the reactivity of QMs with DNA and proteins for the potential application of QMs in medicine as therapeutic agents.
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Affiliation(s)
- Đani Škalamera
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000, Zagreb, Croatia.,Department of Organic Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia
| | - Ivana Antol
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000, Zagreb, Croatia
| | - Kata Mlinarić-Majerski
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000, Zagreb, Croatia
| | - Hrvoj Vančik
- Department of Organic Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
| | - Jiani Ma
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of, Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, P.R. China
| | - Nikola Basarić
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000, Zagreb, Croatia
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9
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Vignoni M, Walalawela N, Bonesi SM, Greer A, Thomas AH. Lipophilic Decyl Chain–Pterin Conjugates with Sensitizer Properties. Mol Pharm 2017; 15:798-807. [DOI: 10.1021/acs.molpharmaceut.7b00136] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Mariana Vignoni
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), CCT La Plata-CONICET, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York 11210, United States
| | - Niluksha Walalawela
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Sergio M. Bonesi
- CIHIDECAR-CONICET, Departamento de Química Orgánica, FCEyN, Universidad de Buenos Aires, Pabellón 2, 3er Piso, Ciudad Universitaria, Buenos Aires, Argentina
| | - Alexander Greer
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Andrés H. Thomas
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), CCT La Plata-CONICET, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina
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Zeng FM, Liu LY, Zheng J, Kong C, An J, Yu YX, Zhang XY, Elfarra AA. Identification of a Fused-Ring 2'-Deoxyadenosine Adduct Formed in Human Cells Incubated with 1-Chloro-3-buten-2-one, a Potential Reactive Metabolite of 1,3-Butadiene. Chem Res Toxicol 2016; 29:1041-50. [PMID: 27161607 DOI: 10.1021/acs.chemrestox.6b00095] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
1-Chloro-3-buten-2-one (CBO) is an in vitro metabolite of 1,3-butadiene (BD), a carcinogenic air pollutant. CBO exhibited potent cytotoxicity and genotoxicity that have been attributed in part to its reactivity toward DNA. Previously, we have characterized the CBO adducts with 2'-deoxycytidine and 2'-deoxyguanosine. In the present study, we report on the reaction of CBO with 2'-deoxyadenosine (dA) under in vitro physiological conditions (pH 7.4, 37 °C). We used the synthesized standards and their decomposition and acid-hydrolysis products to characterize the CBO-DNA adducts formed in human cells. The fused-ring dA adducts (dA-1 and dA-2) were readily synthesized and were structurally characterized as 1,N(6)-(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)-2'-deoxyadenosine and 1,N(6)-(1-hydroxy-1-chloromethylpropan-1,3-diyl)-2'-deoxyadenosine, respectively. dA-1 exhibited a half-life of 16.0 ± 0.7 h and decomposed to dA at pH 7.4 and 37 °C. At similar conditions, dA-2 decomposed to dA-1 and dA, and had a half-life of 0.9 ± 0.1 h. These results provide strong evidence for dA-1 being a degradation product of dA-2. dA-1 is formed by replacement of the chlorine atom of dA-2 by a hydroxyl group. The slow decomposition of dA-1 to dA, along with the detection of hydroxymethyl vinyl ketone (HMVK) as another degradation product, suggested equilibrium between dA-1 and a ring-opened carbonyl-containing intermediate that undergoes a retro-Michael reaction to yield dA and HMVK. Acid hydrolysis of dA-1 and dA-2 yielded the corresponding deribosylated products A-1D and A-2D, respectively. In the acid-hydrolyzed reaction mixture of CBO with calf thymus DNA, both A-1D and A-2D could be detected; however, the amount of A-2D was significantly larger than that of A-1D. Interestingly, only A-2D could be detected by LC-MS analysis of acid-hydrolyzed DNA from cells incubated with CBO, suggesting that dA-2 was stable in DNA and thus may play an important role in the genotoxicity and carcinogenicity of BD. In addition, A-2D could be developed as a biomarker of CBO formation in human cells.
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Affiliation(s)
- Fang-Mao Zeng
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China
| | - Ling-Yan Liu
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China
| | - Jin Zheng
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China
| | - Cong Kong
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences , Shanghai 200090, China
| | - Jing An
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China
| | - Ying-Xin Yu
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China
| | - Xin-Yu Zhang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China
| | - Adnan A Elfarra
- Department of Comparative Biosciences and the Molecular and Environmental Toxicology Center, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
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11
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Naumczuk B, Kawęcki R, Sitkowski J, Bocian W, Bednarek E, Kozerski L. Spontaneous 2′-deoxyguanosine alkylation by a new generation of topoisomerase I inhibitors of the camptothecin family. NEW J CHEM 2016. [DOI: 10.1039/c5nj03497c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
7-Ethyl-9-(N-morpholino)methyl-10-hydroxycamptothecin spontaneously binds covalently to 2′-deoxyguanosine under near-physiological conditions. This phenomenon may be important in the application of this type of camptothecin derivative in cancer chemotherapy.
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Affiliation(s)
- B. Naumczuk
- Institute of Organic Chemistry
- Polish Academy of Sciences
- 01-224 Warsaw
- Poland
| | - R. Kawęcki
- University of Natural Sciences and Humanities
- 80-110 Siedlce
- Poland
| | - J. Sitkowski
- Institute of Organic Chemistry
- Polish Academy of Sciences
- 01-224 Warsaw
- Poland
- National Medicines Institute
| | - W. Bocian
- Institute of Organic Chemistry
- Polish Academy of Sciences
- 01-224 Warsaw
- Poland
- National Medicines Institute
| | - E. Bednarek
- National Medicines Institute
- 00-725 Warsaw
- Poland
| | - L. Kozerski
- Institute of Organic Chemistry
- Polish Academy of Sciences
- 01-224 Warsaw
- Poland
- National Medicines Institute
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Lu W, Teng H, Liu J. How protonation and deprotonation of 9-methylguanine alter its singlet O2 addition path: about the initial stage of guanine nucleoside oxidation. Phys Chem Chem Phys 2016; 18:15223-34. [DOI: 10.1039/c6cp01350c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protonated and deprotonated 9-methylguanine follow completely different oxidation routes.
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Affiliation(s)
- Wenchao Lu
- Department of Chemistry and Biochemistry
- Queens College of the City University of New York
- Queens
- USA
- Ph.D. Program in Chemistry, the Graduate Center of the City University of New York
| | - Huayu Teng
- Department of Chemistry and Biochemistry
- Queens College of the City University of New York
- Queens
- USA
| | - Jianbo Liu
- Department of Chemistry and Biochemistry
- Queens College of the City University of New York
- Queens
- USA
- Ph.D. Program in Chemistry, the Graduate Center of the City University of New York
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13
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Lai Z, Wang Z, Sun J. Organocatalytic Asymmetric Nucleophilic Addition to o-Quinone Methides by Alcohols. Org Lett 2015; 17:6058-61. [DOI: 10.1021/acs.orglett.5b03072] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Zengwei Lai
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Zhaobin Wang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jianwei Sun
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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15
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McCrane MP, Hutchinson MA, Ad O, Rokita SE. Oxidative quenching of quinone methide adducts reveals transient products of reversible alkylation in duplex DNA. Chem Res Toxicol 2014; 27:1282-93. [PMID: 24896651 DOI: 10.1021/tx500152d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
ortho-Quinone methides (ortho-QM) and para-quinone methides are generated by xenobiotic metabolism of numerous compounds including environmental toxins and therapeutic agents. These intermediates are highly electrophilic and have the potential to alkylate DNA. Assessing their genotoxicity can be difficult when all or some of their resulting adducts form reversibly. Stable adducts are most easily detected but are not necessarily the most prevalent products formed initially as DNA repair commences. Selective oxidation of ortho-QM-DNA adducts by bis[(trifluoroacetoxy)iodo]benzene (BTI) rapidly quenches their reversibility to prevent QM regeneration and allows for observation of the kinetic products. The resulting derivatives persist through standard enzymatic digestion, chromatography, and mass spectral analysis. The structural standards required for this approach have been synthesized and confirmed by two-dimensional NMR spectroscopy. The adducts of dA N(6), dG N1, dG N(2), and guanine N7 are converted to the expected para-quinol derivatives within 5 min after addition of BTI under aqueous conditions (pH 7). Concurrently, the adduct of dA N1 forms a spiro derivative comparable to that characterized previously after oxidation of the corresponding dC N3 adduct. By application of this oxidative quenching strategy, the dC N3 and dA N1 adducts have been identified as the dominant products formed by both single- and double-stranded DNA under initial conditions. As expected, however, these labile adducts dissipate within 24 h if not quenched with BTI. Still, the products favored by kinetics are responsible for inducing the first response to ortho-QM exposure in cells, and hence, they are also key to establishing the relationship between biological activity and molecular structure.
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Affiliation(s)
- Michael P McCrane
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742 United States
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16
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Chen W, Han Y, Peng X. Aromatic nitrogen mustard-based prodrugs: activity, selectivity, and the mechanism of DNA cross-linking. Chemistry 2014; 20:7410-8. [PMID: 24806710 DOI: 10.1002/chem.201400090] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Indexed: 12/26/2022]
Abstract
Three novel H2O2-activated aromatic nitrogen mustard prodrugs (6-8) are reported. These compounds contain a DNA alkylating agent connected to a H2O2-responsive trigger by different electron-withdrawing linkers so that they are inactive towards DNA but can be triggered by H2O2 to release active species. The activity and selectivity of these compounds towards DNA were investigated by measuring DNA interstrand cross-link (ICL) formation in the presence or absence of H2O2. An electron-withdrawing linker unit, such as a quaternary ammonia salt (6), a carboxyamide (7), and a carbonate group (8), is sufficient to deactivate the aromatic nitrogen mustard resulting in less than 1.5 % cross-linking formation. However, H2O2 can restore the activity of the effectors by converting a withdrawing group to a donating group, therefore increasing the cross-linking efficiency (>20 %). The stability and reaction sites of the ICL products were determined, which revealed that alkylation induced by 7 and 8 not only occurred at the purine sites but also at the pyrimidine site. For the first time, we isolated and characterized the monomer adducts formed between the canonical nucleosides and the aromatic nitrogen mustard (15) which supported that nitrogen mustards reacted with dG, dA, and dC. The activation mechanism was studied by NMR spectroscopic analysis. An in vitro cytotoxicity assay demonstrated that compound 7 with a carboxyamide linker dramatically inhibited the growth of various cancer cells with a GI50 of less than 1 μM, whereas compound 6 with a charged linker did not show any obvious toxicity in all cell lines tested. These data indicated that a neutral carboxyamide linker is preferable for developing nitrogen mustard prodrugs. Our results showed that 7 is a potent anticancer prodrug that can serve as a model compound for further development. We believe these novel aromatic nitrogen mustards will inspire further and effective applications.
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Affiliation(s)
- Wenbing Chen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 N. Cramer St, Milwaukee, WI 53211 (USA)
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Singh MS, Nagaraju A, Anand N, Chowdhury S. ortho-Quinone methide (o-QM): a highly reactive, ephemeral and versatile intermediate in organic synthesis. RSC Adv 2014. [DOI: 10.1039/c4ra11444b] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In this critical review, we provide a comprehensive view of the chemistry of ortho-quinone methides as versatile reactive intermediates in organic synthesis.
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Affiliation(s)
- Maya Shankar Singh
- Department of Chemistry
- Faculty of Science
- Banaras Hindu University
- Varanasi 221 005, India
| | - Anugula Nagaraju
- Department of Chemistry
- Faculty of Science
- Banaras Hindu University
- Varanasi 221 005, India
| | - Namrata Anand
- Department of Chemistry
- Faculty of Science
- Banaras Hindu University
- Varanasi 221 005, India
| | - Sushobhan Chowdhury
- Department of Chemistry
- Faculty of Science
- Banaras Hindu University
- Varanasi 221 005, India
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18
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Hume PA, Brimble MA, Reynisson J. DNA adduct formation of mitomycin C. A test case for DFT calculations on model systems. COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2012.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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19
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Doria F, Nadai M, Folini M, Di Antonio M, Germani L, Percivalle C, Sissi C, Zaffaroni N, Alcaro S, Artese A, Richter SN, Freccero M. Hybrid ligand-alkylating agents targeting telomeric G-quadruplex structures. Org Biomol Chem 2012; 10:2798-806. [PMID: 22367401 DOI: 10.1039/c2ob06816h] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The synthesis, physico-chemical properties and biological effects of a new class of naphthalene diimides (NDIs) capable of reversibly binding telomeric DNA and alkylate it through an electrophilic quinone methide moiety (QM), are reported. FRET and circular dichroism assays showed a marked stabilization and selectivity towards telomeric G4 DNA folded in a hybrid topology. NDI-QMs' alkylating properties revealed a good reactivity on single nucleosides and selectivity towards telomeric G4. A selected NDI was able to significantly impair the growth of melanoma cells by causing telomere dysfunction and down-regulation of telomerase expression. These findings points to our hybrid ligand-alkylating NDIs as possible tools for the development of novel targeted anticancer therapies.
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Affiliation(s)
- Filippo Doria
- Dipartimento di Chimica, Università di Pavia, V.le Taramelli 10, 27100 Pavia, Italy
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20
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Breugst M, Corral Bautista F, Mayr H. Nucleophilic Reactivities of the Anions of Nucleobases and Their Subunits. Chemistry 2011; 18:127-37. [DOI: 10.1002/chem.201102411] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Indexed: 11/10/2022]
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21
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Manso JA, Camacho IFC, Calle E, Casado J. Alkylating potential of α,β-unsaturated compounds. Org Biomol Chem 2011; 9:6226-33. [PMID: 21773622 DOI: 10.1039/c1ob05298e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alkylation reactions of the nucleoside guanosine (Guo) by the α,β-unsaturated compounds (α,β-UC) acrylonitrile (AN), acrylamide (AM), acrylic acid (AA) and acrolein (AC), which can act as alkylating agents of DNA, were investigated kinetically. The following conclusions were drawn: i) The Guo alkylation mechanism by AC is different from those brought about the other α,β-UC; ii) for the first three, the following sequence of alkylating potential was found: AN > AM > AA; iii) A correlation between the chemical reactivity (alkylation rate constants) of AN, AM, and AA and their capacity to form adducts with biomarkers was found. iv) Guo alkylation reactions for AN and AM occur through Michael addition mechanisms, reversible in the first case, and irreversible in the second. The equilibrium constant for the formation of the Guo-AN adduct is K(eq) (37 °C) = 5 × 10(-4); v) The low energy barrier (≈10 kJ mol(-1)) to reverse the Guo alkylation by AN reflects the easy reversibility of this reaction and its possible correction by repair mechanisms; vi) No reaction was observed for AN, AM, and AA at pH < 8.0. In contrast, Guo alkylation by AC was observed under cellular pH conditions. The reaction rate constants for the formation of the α-OH-Guo adduct (the most genotoxic isomer), is 1.5-fold faster than that of γ-OH-Guo. vii) a correlation between the chemical reactivity of α,β-UC (alkylation rate constants) and mutagenicity was found.
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Affiliation(s)
- José A Manso
- Departamento de Química Física, Universidad de Salamanca, Salamanca, Spain
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22
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Dixit VA, Bharatam PV. Toxic Metabolite Formation from Troglitazone (TGZ): New Insights from a DFT Study. Chem Res Toxicol 2011; 24:1113-22. [DOI: 10.1021/tx200110h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vaibhav A. Dixit
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab-160062, India
| | - Prasad V. Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S. A. S. Nagar, Punjab-160062, India
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23
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Nadai M, Doria F, Di Antonio M, Sattin G, Germani L, Percivalle C, Palumbo M, Richter SN, Freccero M. Naphthalene diimide scaffolds with dual reversible and covalent interaction properties towards G-quadruplex. Biochimie 2011; 93:1328-40. [PMID: 21699955 DOI: 10.1016/j.biochi.2011.06.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 06/14/2011] [Indexed: 11/26/2022]
Abstract
Selective recognition and alkylation of G-quadruplex oligonucleotides has been achieved by substituted naphathalene diimides (NDIs) conjugated to engineered phenol moieties by alkyl-amido spacers with tunable length and conformational mobility. FRET-melting assays, circular dichroism titrations and gel electrophoresis analysis have been carried out to evaluate both reversible stabilization and alkylation of the G-quadruplex. The NDIs conjugated to a quinone methide precursor (NDI-QMP) and a phenol moiety by the shortest alkyl-amido spacer exhibited a planar and fairly rigid geometry (modelled by DFT computation). They were the best irreversible and reversible G-quadruplex binders, respectively. The above NDI-QMP was able to alkylate the telomeric G-quadruplex DNA in the nanomolar range and resulted 100-1000 times more selective on G-quadruplex versus single- and double-stranded oligonucleotides. This compound was also the most cytotoxic against a lung carcinoma cell line.
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Affiliation(s)
- Matteo Nadai
- Dipartimento di Istologia, Microbiologia e Biotecnologie Mediche, via Gabelli 63, Padua, Italy
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24
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Verga D, Nadai M, Doria F, Percivalle C, Di Antonio M, Palumbo M, Richter SN, Freccero M. Photogeneration and reactivity of naphthoquinone methides as purine selective DNA alkylating agents. J Am Chem Soc 2011; 132:14625-37. [PMID: 20863115 DOI: 10.1021/ja1063857] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A one-step protecting-group-free synthesis of both 6-hydroxy-naphthalene-2-carbaldehyde and the bifunctional binaphthalenyl derivative afforded 6-hydroxymethylnaphthalen-2-ol, 6-methylaminomethyl-naphthalen-2-ol, [(2-hydroxy-3-naphthyl)methyl]trimethyl ammonium iodide, and a small library of bifunctional binol analogues in good yields. Irradiation of naphthol quaternary ammonium salt and binol-derivatives (X = OH, NHR, NMe(3)(+), OCOCH(3), and L-proline) at 310 and 360 nm resulted in the photogeneration of the 2,6-naphthoquinone-6-methide (NQM) and binol quinone methide analogues (BQMs) by a water-mediated excited-state proton transfer (ESPT). The hydration, the mono- and bis-alkylation reactions of morpholine and 2-ethanethiol, as N and S prototype nucleophiles, by the transient NQM (λ(max) 310, 330 nm) and BQMs (λ(max) 360 nm) were investigated in water by product distribution analysis and laser flash photolysis (LFP). Both the photogeneration and the reactivity of NQM and BQMs exhibited striking differences. BQMs were at least 2 orders of magnitude more reactive than NQM, and they were generated much more efficiently from a greater variety of photoprecursors including the hydroxymethyl, quaternary ammonium salt and several binol-amino acids. On the contrary, the only efficient precursor of NQM was the quaternary ammonium salt. All water-soluble BQM precursors were further investigated for their ability to alkylate and cross-link plasmid DNA and oligonucleotides by gel electrophoresis: the BQMs were more efficient than the isomeric o-BQM (binol quinone methide analogue of 2,3-naphthoquinone-3-methide). Sequence analysis by gel electrophoresis, HPLC, and MS showed that the alkylation occurred at purines, with a preference for guanine. In particular, a BQM was able to alkylate N7 of guanines resulting in depurination at the oligonucleotide level, and ribose loss at the nucleotide level. The photoreactivity of BQM precursors translated into photocytotoxic and cytotoxic effects on two human cancer cell lines: in particular, one compound showed promising selectivity index on both cell lines.
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Affiliation(s)
- Daniela Verga
- Dipartimento di Chimica Organica, Università di Pavia, V. le Taramelli 10, 27100 Pavia, Italy
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25
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Quinone methides tethered to naphthalene diimides as selective G-quadruplex alkylating agents. J Am Chem Soc 2010; 131:13132-41. [PMID: 19694465 DOI: 10.1021/ja904876q] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have developed novel G-quadruplex (G-4) ligand/alkylating hybrid structures, tethering the naphthalene diimide moiety to quaternary ammonium salts of Mannich bases, as quinone-methide precursors, activatable by mild thermal digestion (40 degrees C). The bis-substituted naphthalene diimides were efficiently synthesized, and their reactivity as activatable bis-alkylating agents was investigated in the presence of thiols and amines in aqueous buffered solutions. The electrophilic intermediate, quinone-methide, involved in the alkylation process was trapped, in the presence of ethyl vinyl ether, in a hetero Diels-Alder [4 + 2] cycloaddition reaction, yielding a substituted 2-ethoxychroman. The DNA recognition and alkylation properties of these new derivatives were investigated by gel electrophoresis, circular dichroism, and enzymatic assays. The alkylation process occurred preferentially on the G-4 structure in comparison to other DNA conformations. By dissecting reversible recognition and alkylation events, we found that the reversible process is a prerequisite to DNA alkylation, which in turn reinforces the G-quadruplex structural rearrangement.
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26
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Ferreira SB, da Silva FDC, Pinto AC, Gonzaga DTG, Ferreira VF. Syntheses of chromenes and chromanesvia o-quinone methide intermediates. J Heterocycl Chem 2009. [DOI: 10.1002/jhet.232] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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27
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Richter SN, Menegazzo I, Nadai M, Moro S, Palumbo M. Reactivity of clerocidin towards adenine: implications for base-modulated DNA damage. Org Biomol Chem 2009; 7:976-85. [PMID: 19225681 DOI: 10.1039/b819049f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Clerocidin is a complex natural molecule which induces DNA damage both directly and through irreversible/reversible poisoning of prokaryotic/eukaryotic topoisomerases II. By analysis of clerocidin reactivity towards adenine and thymine bases, we were able to fully characterize and compare the unique direct reactivity of clerocidin towards the four DNA bases, both in solution and in the DNA context. We showed that thymine was not reactive, while adenine gave a single stable covalent adduct, which was unambiguously identified as the 1,6-dialkylated species by means of modified clerocidin derivatives, modified adenine nucleotides, ESI-MS and multinuclear NMR spectroscopy. The mechanism of formation of the clerocidin adenosine adduct was similar to that occurring with cytosine, while being substantially different from that with guanine. An electrophoresis-based assay was able to highlight the unique ability of clerocidin to chemically discriminate among DNA nucleotides within a nucleic acid sequence. Finally, molecular modelling analysis gave useful indications to solve the apparent contradiction between direct and topoisomerase II-mediated covalent clerocidin reactivity with deoxyadenosine.
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Affiliation(s)
- Sara N Richter
- Department of Histology, Microbiology and Medicinal Biotechnologies, University of Padova, 35131 Padova, Italy
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28
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Wang H, Wahi MS, Rokita SE. Immortalizing a transient electrophile for DNA cross-linking. Angew Chem Int Ed Engl 2008; 47:1291-3. [PMID: 18175300 DOI: 10.1002/anie.200704137] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Huan Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
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29
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Wang H, Wahi M, Rokita S. Immortalizing a Transient Electrophile for DNA Cross-Linking. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200704137] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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30
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Weinert EE, Dondi R, Colloredo-Melz S, Frankenfield KN, Mitchell CH, Freccero M, Rokita SE. Substituents on quinone methides strongly modulate formation and stability of their nucleophilic adducts. J Am Chem Soc 2007; 128:11940-7. [PMID: 16953635 PMCID: PMC2538442 DOI: 10.1021/ja062948k] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Electronic perturbation of quinone methides (QM) greatly influences their stability and in turn alters the kinetics and product profile of QM reaction with deoxynucleosides. Consistent with the electron-deficient nature of this reactive intermediate, electron-donating substituents are stabilizing and electron-withdrawing substituents are destabilizing. For example, a dC N3-QM adduct is made stable over the course of observation (7 days) by the presence of an electron-withdrawing ester group that inhibits QM regeneration. Conversely, a related adduct with an electron-donating methyl group is very labile and regenerates its QM with a half-life of approximately 5 h. The generality of these effects is demonstrated with a series of alternative quinone methide precursors (QMP) containing a variety of substituents attached at different positions with respect to the exocyclic methylene. The rates of nucleophilic addition to substituted QMs measured by laser flash photolysis similarly span 5 orders of magnitude with electron-rich species reacting most slowly and electron-deficient species reacting most quickly. The reversibility of QM reaction can now be predictably adjusted for any desired application.
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Affiliation(s)
- Emily E. Weinert
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742 USA
| | - Ruggero Dondi
- Dipartimento di Chimica Organica, Università di Pavia, V.le Taramelli 10, 27100 Pavia, Italy
| | - Stefano Colloredo-Melz
- Dipartimento di Chimica Organica, Università di Pavia, V.le Taramelli 10, 27100 Pavia, Italy
| | - Kristen N. Frankenfield
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742 USA
| | - Charles H. Mitchell
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742 USA
| | - Mauro Freccero
- Dipartimento di Chimica Organica, Università di Pavia, V.le Taramelli 10, 27100 Pavia, Italy
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| | - Steven E. Rokita
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742 USA
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31
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da Silva MN, Ferreira SB, Jorqueira A, de Souza MC, Pinto AV, Kaiser CR, Ferreira VF. Synthesis of new carbonyl and fluoroalkyl o-quinone methides from β-lapachone. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.06.145] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Zhou Q, Xu T, Mangrum JB. Selective N1-Alkylation of 2′-Deoxyguanosine with a Quinolinyl Quinone Methide. Chem Res Toxicol 2007; 20:1069-74. [PMID: 17630703 DOI: 10.1021/tx700162d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nucleobase modification by quinone methides (QMs) has been extensively studied in the past decade, and multiple QM adducts were observed. For 2'-deoxyguanosine (dG), the N (2)-dG alkylation adduct was favored under aqueous buffered conditions over other N1-dG, N7-dG, and N7-guanine adducts. We report in this communication that the N1-dG adduct was selectively formed with a quinolinyl QM in 30% aqueous DMF and 10 mM phosphate buffer (pH 7.0) as a favored dG alkylation product. The quinolinyl QM was formed through the fluoride-induced desilylation and elimination of acetate, and the structure of the N1-dG adduct was fully established by one- and two-dimensional NMR analyses. In addition, the concentration of salt played a significant role in N1-dG adduct formation. Further HPLC analysis indicated that the addition of salt decreased the rate of QM formation from the acetate intermediate, although an in-depth mechanistic study is needed.
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Affiliation(s)
- Qibing Zhou
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA.
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Sund P, Kronberg L. Reaction of epichlorohydrin with adenosine, 2'-deoxyadenosine and calf thymus DNA: identification of adducts. Bioorg Chem 2006; 34:115-30. [PMID: 16549090 DOI: 10.1016/j.bioorg.2006.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Accepted: 01/25/2006] [Indexed: 11/19/2022]
Abstract
Epichlorohydrin (a probable human carcinogen) was allowed to react with adenosine and the adducts were characterized by NMR and UV spectroscopy, and mass spectrometry. The adduct initially formed was 1-(3-chloro-2-hydroxypropyl)-adenosine, which subsequently ring closures to 1,N(6)-(2-hydroxypropyl)-adenosine at neutral and basic conditions. At acid conditions, the N-1 adduct undergoes a slow deamination to yield 1-(3-chloro-2-hydroxypropyl)-inosine. Minor adducts identified were 7-(3-chloro-2-hydroxypropyl)-adenosine and 3-(3-chloro-2-hydroxypropyl)-adenosine which are easily deglycosylated, and an adduct where the epichlorohydrin residue was attached to the sugar moiety of adenosine. A diadduct, 1,N(6)-(2-hydroxypropyl)-N(6)-(3-chloro-2-hydroxypropyl)-adenosine was also identified. The reaction of epichlorohydrin with calf thymus DNA gave 1,N(6)-(2-hydroxypropyl)-deoxyadenosine and 3-(3-chloro-2-hydroxypropyl)-adenine (major adduct).
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Affiliation(s)
- Pernilla Sund
- Department of Organic Chemistry, Abo Akademi University, Biskopsgatan 8, FIN-20500 Turkul Abo, Finland
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Freccero M, Gandolfi R. Modeling Acid and Cationic Catalysis on the Reactivity of Duocarmycins. J Org Chem 2005; 70:7098-106. [PMID: 16122228 DOI: 10.1021/jo050751p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several catalyzed alkylation reactions of 9-methyladenine by a model [CPI, cyclopropa[c]pyrrolo[3,2-e]indol-4(5H)-one (1)] of duocarmycin anticancer drugs have been compared to the uncatalyzed reaction in gas phase and in water solvent bulk, using density functional theory at the B3LYP level with the 6-31+G(d,p) basis set and C-PCM solvation model. The effect on the CPI reactivity induced by water, formic and phosphoric acids (general acid catalysis), H3O+ (specific acid catalysis), sodium, and ammonium cation complexation (cationic catalysis) has been investigated. The calculations indicate that the specific acid catalysis and the catalysis induced by sodium cation complexation are strong in the gas phase, but solvation reduces them dramatically by electrostatic effects. The specific acid catalysis is still operative, but strongly reduced in water solution, where the reaction barrier is reduced by 8.6 kcal mol(-1) in comparison to the uncatalyzed reaction. The general acid catalysis induced by phosphoric acid (-7.3 kcal mol(-1)) and the catalysis induced by Na+ and NH4+ complexation become competitive, with a catalytic effect of -3.6 and -4.1 kcal mol(-1) in water, respectively. With the specific acid catalysis, the high acidity (low pK(a) value) of the conjugated acid of CPI (CPIH+), computed in water solution using both C-PCM (pK(a) = +2.6) and PCM-B3LYP/6-31+G(d,p) (pK(a) = +2.4) solvation models, suggests that the catalytic effects induced by NH4+ complexation could become more important than the specific acid catalysis and the general catalysis by H3PO4 under physiological conditions, due to concentration effects of the catalysts.
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Affiliation(s)
- Mauro Freccero
- Dipartimento di Chimica Organica, Università di Pavia, V.le Taramelli 10, 27100 Pavia Italy.
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35
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Freccero M, Gandolfi R. Modeling Substituent and Conformational Effects on the Reactivity of Antitumor Agents Containing a Cyclopropylcyclohexadienone Subunit. J Org Chem 2004; 69:6202-13. [PMID: 15357577 DOI: 10.1021/jo049193p] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The uncatalyzed alkylation reactions of ammonia by the parent spirocyclopropylcyclohexadienone (6), its 3-amino analogue (7), the cyclic derivative (8), its N-formyl derivative (9), and a closer model (10) of the CPI (1-4) drugs have been investigated in gas phase and in water solvent bulk, using density functional theory at the B3LYP level with several basis sets and the C-PCM solvation model. The effect of several structural key features such as the vinylogous amide conjugation, the acylation of the 2-amino substituent, the ring constraint of the heterocyclic nitrogen atom at C(2) carbon in a ring, and the presence of a condensed pyrrole ring on the reaction activation energy have been investigated. Substrate 7, which is a flexible conformational model of the cyclopropylpyrroloindole moiety (CPI) contained in the duocarmycins, has been used to model the shape-dependent reactivity of these drugs, in gas phase and water solutions. The calculations indicate that shape dependence of reactivity is strongly operative both in gas phase and in polar solvents, since conformational effects are capable of reducing the reaction activation energy by -8.4 and -4.3 kcal mol(-1) in gas phase and in water solution, respectively, that is required to promote "conformational catalysis".
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Affiliation(s)
- Mauro Freccero
- Dipartimento di Chimica Organica, Università di Pavia, V.le Taramelli 10, 27100 Pavia, Italy.
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