1
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Reyes Y, Adhikary A, Wnuk SF. Nitrogen-Centered Radicals Derived from Azidonucleosides. Molecules 2024; 29:2310. [PMID: 38792171 PMCID: PMC11124349 DOI: 10.3390/molecules29102310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/04/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Azido-modified nucleosides have been extensively explored as substrates for click chemistry and the metabolic labeling of DNA and RNA. These compounds are also of interest as precursors for further synthetic elaboration and as therapeutic agents. This review discusses the chemistry of azidonucleosides related to the generation of nitrogen-centered radicals (NCRs) from the azido groups that are selectively inserted into the nucleoside frame along with the subsequent chemistry and biological implications of NCRs. For instance, the critical role of the sulfinylimine radical generated during inhibition of ribonucleotide reductases by 2'-azido-2'-deoxy pyrimidine nucleotides as well as the NCRs generated from azidonucleosides by radiation-produced (prehydrated and aqueous) electrons are discussed. Regio and stereoselectivity of incorporation of an azido group ("radical arm") into the frame of nucleoside and selective generation of NCRs under reductive conditions, which often produce the same radical species that are observed upon ionization events due to radiation and/or other oxidative conditions that are emphasized. NCRs generated from nucleoside-modified precursors other than azidonucleosides are also discussed but only with the direct relation to the same/similar NCRs derived from azidonucleosides.
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Affiliation(s)
- Yahaira Reyes
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA;
| | - Amitava Adhikary
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA;
| | - Stanislaw F. Wnuk
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA;
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2
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Reyes Y, Mebel A, Wnuk SF. 6-azido and 6-azidomethyl uracil nucleosides. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2023; 43:453-471. [PMID: 37859415 DOI: 10.1080/15257770.2023.2271023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023]
Abstract
Azido nucleosides have been utilized for click reactions, metabolic incorporation into cellular DNA, and fluorescent imaging of live cells. Two classes of 6-azido modified uracil nucleosides; one with azido group directly attached to uracil ring and second with azido group attached via methylene linker are described. The 6-azido-2'-deoxyuridine (6-AdU) was prepared in 55% overall yield by lithiation-based regioselective C6-iodination of silyl protected 2'-deoxyuridine followed by treatment with sodium azide and deprotection with TBAF. Lithiation-based C6-alkylation of the protected uridine with methyl iodide followed by the oxidation of the 6-methyl product with selenium dioxide and the subsequent mesylation and azidation of the resulting 6-hydroxymethyl group gave after deprotection 6-azidomethyluridine (6-AmU) in 61% overall yield. Direct lithiation-based C6-hydroxymethylation followed by mesylation/azidation sequence and deprotection provided 6-AmU or 6-azidomethyl-2'-deoxyuridine (6-AmdU). Yields for the lithiation-based regioselective C6-iodination and alkylation were higher for uridine than 2'-deoxyuridine derivatives and they appear to be less dependent on the sugar protection group used. Strain promoted click reactions of 6-AdU and 6-AmdU with symmetrically fused cyclopropyl cyclooctyne (OCT) provided fluorescent triazoles. DFT-calculated dihedral angles and energy differences for the favored anti and syn conformation of 6-AdU and 6-AmdU versus their C5 azido counterparts are discussed.
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Affiliation(s)
- Yahaira Reyes
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA
| | - Alexander Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA
| | - Stanislaw F Wnuk
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA
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3
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Peng H, Vu S, Retes P, Ward S, Kumar A, Sevilla MD, Adhikary A, Greenberg MM. Photochemical and Single Electron Transfer Generation of 2'-Deoxycytidin- N4-yl Radical from Oxime Esters. J Org Chem 2023; 88:7381-7390. [PMID: 37220149 PMCID: PMC10308854 DOI: 10.1021/acs.joc.3c00646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A 2'-deoxycytidin-N4-yl radical (dC·), a strong oxidant that also abstracts hydrogen atoms from carbon-hydrogen bonds, is produced in a variety of DNA damaging processes. We describe here the independent generation of dC· from oxime esters under UV-irradiation or single electron transfer conditions. Support for this σ-type iminyl radical generation is provided by product studies carried out under aerobic and anaerobic conditions, as well as electron spin resonance (ESR) characterization of dC· in a homogeneous glassy solution at low temperature. Density functional theory (DFT) calculations also support fragmentation of the corresponding radical anions of oxime esters 2d and 2e to dC· and subsequent hydrogen atom abstraction from organic solvents. The corresponding 2'-deoxynucleotide triphosphate (dNTP) of isopropyl oxime ester 2c (5) is incorporated opposite 2'-deoxyadenosine and 2'-deoxyguanosine by a DNA polymerase with approximately equal efficiency. Photolysis experiments of DNA containing 2c support dC· generation and indicate that the radical produces tandem lesions when flanked on the 5'-side by 5'-d(GGT). These experiments suggest that oxime esters are reliable sources of nitrogen radicals in nucleic acids that will be useful mechanistic tools and possibly radiosensitizing agents when incorporated in DNA.
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Affiliation(s)
- Haihui Peng
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, United States
| | - Son Vu
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, United States
| | - Parker Retes
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Samuel Ward
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Anil Kumar
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Michael D Sevilla
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Amitava Adhikary
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Marc M Greenberg
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, United States
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4
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Adjei D, Reyes Y, Kumar A, Ward S, Denisov SA, Alahmadi M, Sevilla MD, Wnuk SF, Mostafavi M, Adhikary A. Pathways of the Dissociative Electron Attachment Observed in 5- and 6-Azidomethyluracil Nucleosides: Nitrogen (N 2) Elimination vs Azide Anion (N 3-) Elimination. J Phys Chem B 2023; 127:1563-1571. [PMID: 36780335 PMCID: PMC9984991 DOI: 10.1021/acs.jpcb.2c08257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
5-Azidomethyl-2'-deoxyuridine (5-AmdU, 1) has been successfully employed for the metabolic labeling of DNA and fluorescent imaging of live cells. 5-AmdU also demonstrated significant radiosensitization in breast cancer cells via site-specific nitrogen-centered radical (π-aminyl (U-5-CH2-NH•), 2, and σ-iminyl (U-5-CH═N•), 3) formation. This work shows that these nitrogen-centered radicals are not formed via the reduction of the azido group in 6-azidomethyluridine (6-AmU, 4). Radical assignments were performed using electron spin resonance (ESR) in supercooled solutions, pulse radiolysis in aqueous solutions, and theoretical (DFT) calculations. Radiation-produced electron addition to 4 leads to the facile N3- loss, forming a stable neutral C-centered allylic radical (U-6-CH2•, 5) through dissociative electron attachment (DEA) via the transient negative ion, TNI (U-6-CH2-N3•-), in agreement with DFT calculations. In contrast, TNI (U-5-CH2-N3•-) of 1, via facile N2 loss (DEA) and protonation from the surrounding water, forms radical 2. Subsequently, 2 undergoes rapid H-atom abstraction from 1 and produces the metastable intermediate α-azidoalkyl radical (U-5-CH•-N3). U-5-CH•-N3 converts facilely to radical 3. N3- loss from U-6-CH2-N3•- is thermodynamically controlled, whereas N2 loss from U-5-CH2-N3•- is dictated by protonation from the surrounding waters and resonance conjugation of the azidomethyl side chain at C5 with the pyrimidine ring.
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Affiliation(s)
- Daniel Adjei
- Institut de Chimie Physique, UMR 8000 CNRS, Bât. 349, Université Paris-Saclay; 91405, Orsay, Cedex, France
| | - Yahaira Reyes
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, USA
| | - Anil Kumar
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, Michigan 48309, USA
| | - Samuel Ward
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, Michigan 48309, USA
| | - Sergey A. Denisov
- Institut de Chimie Physique, UMR 8000 CNRS, Bât. 349, Université Paris-Saclay; 91405, Orsay, Cedex, France
| | - Moaadh Alahmadi
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, Michigan 48309, USA
| | - Michael D. Sevilla
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, Michigan 48309, USA
| | - Stanislaw F. Wnuk
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, USA
| | - Mehran Mostafavi
- Institut de Chimie Physique, UMR 8000 CNRS, Bât. 349, Université Paris-Saclay; 91405, Orsay, Cedex, France
| | - Amitava Adhikary
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, Michigan 48309, USA
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5
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Conder CJ, Jawale H, Wenthold PG. Mass spectrometry studies of nitrene anions. MASS SPECTROMETRY REVIEWS 2021:e21751. [PMID: 34842299 DOI: 10.1002/mas.21751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
Nitrene anions are a class of reactive intermediates that provide a means for studying the corresponding neutral molecules via electron photodetachment spectroscopy and photoelectron spectroscopy. The added electron makes it possible for protected nitrene anions to be manipulated by external electric and magnetic fields of a mass spectrometer. Nitrene anions also display their own unique reactivities as reagents, which have been investigated using ion/molecule reactions. Mass spectrometry of negative ions has thereby provided information on the electronic states, reactivities, and thermochemical properties of nitrene intermediates. This review also includes a discussion of condensed-phase nitrene anions.
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Affiliation(s)
- Cory J Conder
- Department of Chemistry, Purdue University, West Lafayette, Indiana, USA
| | - Harshal Jawale
- Department of Chemistry, Purdue University, West Lafayette, Indiana, USA
| | - Paul G Wenthold
- Department of Chemistry, Purdue University, West Lafayette, Indiana, USA
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6
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Kant M, Jaruga P, Coskun E, Ward S, Stark AD, Baumann T, Becker D, Adhikary A, Sevilla MD, Dizdaroglu M. Ne-22 Ion-Beam Radiation Damage to DNA: From Initial Free Radical Formation to Resulting DNA-Base Damage. ACS OMEGA 2021; 6:16600-16611. [PMID: 34235332 PMCID: PMC8246699 DOI: 10.1021/acsomega.1c01954] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/31/2021] [Indexed: 06/13/2023]
Abstract
We report on the physicochemical processes and the products of DNA damage involved in Ne-22 ion-beam radiation of hydrated (12 ± 3 H2O/nucleotide) salmon testes DNA at 77 K. Free radicals trapped at 77 K were identified using electron spin resonance (ESR) spectroscopy. The measurement of DNA damage using two different techniques of mass spectrometry revealed the formation of numerous DNA products. Results obtained by ESR spectroscopy showed that as the linear energy transfer (LET) of the ion-beam radiation increases along the beam track, the production of DNA radicals correspondingly increases until just before the Bragg peak is reached. Yields of DNA products along the ion-beam track were in excellent agreement with the radical production. This work is the first to use the combination of ESR spectroscopy and mass spectrometric techniques enabling a better understanding of mechanisms of radiation damage to DNA by heavy ion beams detailing the formation of DNA free radicals and their subsequent products.
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Affiliation(s)
- Melis Kant
- Biomolecular
Measurement Division, National Institute
of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Pawel Jaruga
- Biomolecular
Measurement Division, National Institute
of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Erdem Coskun
- Biomolecular
Measurement Division, National Institute
of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
- Institute
for Bioscience & Biotechnology Research, University of Maryland, 9600 Gudelsky Way, Rockville, Maryland 20850, United
States
| | - Samuel Ward
- Department
of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Alexander D. Stark
- Department
of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Thomas Baumann
- National
Superconducting Cyclotron Laboratory, Michigan
State University, 640
South Shaw Lane, East Lansing, Michigan 48824, United
States
| | - David Becker
- Department
of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Amitava Adhikary
- Department
of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Michael D. Sevilla
- Department
of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Miral Dizdaroglu
- Biomolecular
Measurement Division, National Institute
of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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7
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Mudgal M, Dang TP, Sobczak AJ, Lumpuy DA, Dutta P, Ward S, Ward K, Alahmadi M, Kumar A, Sevilla MD, Wnuk SF, Adhikary A. Site of Azido Substitution in the Sugar Moiety of Azidopyrimidine Nucleosides Influences the Reactivity of Aminyl Radicals Formed by Dissociative Electron Attachment. J Phys Chem B 2020; 124:11357-11370. [PMID: 33270461 DOI: 10.1021/acs.jpcb.0c08201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this work, electron-induced site-specific formation of neutral π-type aminyl radicals (RNH·) and their reactions with pyrimidine nucleoside analogs azidolabeled at various positions in the sugar moiety, e.g., at 2'-, 3'-, 4'-, and 5'- sites along with a model compound 3-azido-1-propanol (3AZPrOH), were investigated. Electron paramagnetic resonance (EPR) studies confirmed the site and mechanism of RNH· formation via dissociative electron attachment-mediated loss of N2 and subsequent facile protonation from the solvent employing the 15N-labeled azido group, deuterations at specific sites in the sugar and base, and changing the solvent from H2O to D2O. Reactions of RNH· were investigated employing EPR by warming these samples from 77 K to ca. 170 K. RNH· at a primary carbon site (5'-azido-2',5'-dideoxyuridine, 3AZPrOH) facilely converted to a σ-type iminyl radical (R═N·) via a bimolecular H-atom abstraction forming an α-azidoalkyl radical. RNH· when at a secondary carbon site (e.g., 2'-azido-2'-deoxyuridine) underwent bimolecular electrophilic addition to the C5═C6 double bond of a proximate pyrimidine base. Finally, RNH· at tertiary alkyl carbon (4'-azidocytidine) underwent little reaction. These results show the influence of the stereochemical and electronic environment on RNH· reactivity and allow the selection of those azidonucleosides that would be most effective in augmenting cellular radiation damage.
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Affiliation(s)
- Mukesh Mudgal
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Thao P Dang
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Adam J Sobczak
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Daniel A Lumpuy
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Priya Dutta
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Samuel Ward
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Katherine Ward
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Moaadh Alahmadi
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Anil Kumar
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Michael D Sevilla
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Stanislaw F Wnuk
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Amitava Adhikary
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
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8
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Verma A, Adhikary A, Woloschak G, Dwarakanath BS, Papineni RVL. A combinatorial approach of a polypharmacological adjuvant 2-deoxy-D-glucose with low dose radiation therapy to quell the cytokine storm in COVID-19 management. Int J Radiat Biol 2020; 96:1323-1328. [PMID: 32910699 DOI: 10.1080/09553002.2020.1818865] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pandemic disease and is the major cause of deaths worldwide. The clinical complexities (inflammation, cytokine storm, and multi-organ dysfunction) associated with COVID-19 poses constraints to effective management of critically ill COVID-19 patients. Low dose radiation therapy (LDRT) has been evaluated as a potential therapeutic modality for COVID-19 pneumonia. However, due to heterogeneity in disease manifestation and inter-individual variations, effective planning for LDRT is limited for this large-scale event. 2-deoxy-D-glucose (2-DG) has emerged as a polypharmacological agent for COVID-19 treatment due to its effects on the glycolytic pathway, anti-inflammatory action, and interaction with viral proteins. We suggest that 2-DG will be a potential adjuvant to enhance the efficacy of LDRT in the treatment of COVID-19 pneumonia. Withal, azido analog of 2-DG, 2-azido-2-DG can produce rapid catastrophic oxidative stress and quell the cytokine storm in critically ill COVID-19 patients.
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Affiliation(s)
| | | | - Gayle Woloschak
- Department of Radiobiology, Northwestern University's Feinberg School of Medicine, Chicago, IL, USA
| | - Bilikere S Dwarakanath
- Department of Research and Development, Shanghai Proton and Heavy Ion Center, Shanghai, People's Republic of China
| | - Rao V L Papineni
- Department of Surgery, University of Kansas Medical Center (Adjunct), and PACT & Health LLC, Branford, CT, USA
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9
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Birudukota N, Mudgal MM, Shanbhag V. Discovery and development of azasteroids as anticancer agents. Steroids 2019; 152:108505. [PMID: 31568765 DOI: 10.1016/j.steroids.2019.108505] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 08/27/2019] [Accepted: 09/24/2019] [Indexed: 12/14/2022]
Abstract
Cancer is the second leading cause of death worldwide following cardiovascular diseases. Cancer can be treated by a variety of techniques including surgery, radiation therapy, immunotherapy, and chemotherapy. Choice of the method can be made based on type, physiologic location and the stage of disease progression. Among chemical methods, steroids find broad applications. Azasteroids have N- substitutions in steroidal rings. This structural modification renders azasteroids advantageous in increased effectiveness and reduced side effects. Numerous accounts of cancer efficacy of this family of compounds are available in literature. The progress made in the discovery, synthetic efforts and development of azasteroids as anticancer agents is broadly outlined in this review.
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Affiliation(s)
- Nagaraju Birudukota
- Department of Chemistry and Physics, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Fort Lauderdale, FL 33314, USA
| | - Mukesh Madan Mudgal
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, USA.
| | - Venkatesh Shanbhag
- Department of Chemistry and Physics, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Fort Lauderdale, FL 33314, USA
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10
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Kumar A, Becker D, Adhikary A, Sevilla MD. Reaction of Electrons with DNA: Radiation Damage to Radiosensitization. Int J Mol Sci 2019; 20:E3998. [PMID: 31426385 PMCID: PMC6720166 DOI: 10.3390/ijms20163998] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/01/2019] [Accepted: 08/12/2019] [Indexed: 01/19/2023] Open
Abstract
This review article provides a concise overview of electron involvement in DNA radiation damage. The review begins with the various states of radiation-produced electrons: Secondary electrons (SE), low energy electrons (LEE), electrons at near zero kinetic energy in water (quasi-free electrons, (e-qf)) electrons in the process of solvation in water (presolvated electrons, e-pre), and fully solvated electrons (e-aq). A current summary of the structure of e-aq, and its reactions with DNA-model systems is presented. Theoretical works on reduction potentials of DNA-bases were found to be in agreement with experiments. This review points out the proposed role of LEE-induced frank DNA-strand breaks in ion-beam irradiated DNA. The final section presents radiation-produced electron-mediated site-specific formation of oxidative neutral aminyl radicals from azidonucleosides and the evidence of radiosensitization provided by these aminyl radicals in azidonucleoside-incorporated breast cancer cells.
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Affiliation(s)
- Anil Kumar
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - David Becker
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Amitava Adhikary
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Michael D Sevilla
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA.
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11
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Wen Z, Peng J, Tuttle PR, Ren Y, Garcia C, Debnath D, Rishi S, Hanson C, Ward S, Kumar A, Liu Y, Zhao W, Glazer PM, Liu Y, Sevilla MD, Adhikary A, Wnuk SF. Electron-Mediated Aminyl and Iminyl Radicals from C5 Azido-Modified Pyrimidine Nucleosides Augment Radiation Damage to Cancer Cells. Org Lett 2018; 20:7400-7404. [PMID: 30457873 PMCID: PMC6465127 DOI: 10.1021/acs.orglett.8b03035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two classes of azido-modified pyrimidine nucleosides were synthesized as potential radiosensitizers; one class is 5-azidomethyl-2'-deoxyuridine (AmdU) and cytidine (AmdC), while the second class is 5-(1-azidovinyl)-2'-deoxyuridine (AvdU) and cytidine (AvdC). The addition of radiation-produced electrons to C5-azido nucleosides leads to the formation of π-aminyl radicals followed by facile conversion to σ-iminyl radicals either via a bimolecular reaction involving intermediate α-azidoalkyl radicals in AmdU/AmdC or by tautomerization in AvdU/AvdC. AmdU demonstrates effective radiosensitization in EMT6 tumor cells.
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Affiliation(s)
- Zhiwei Wen
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Jufang Peng
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Paloma R. Tuttle
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Yaou Ren
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Carol Garcia
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Dipra Debnath
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Sunny Rishi
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Cameron Hanson
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Samuel Ward
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Anil Kumar
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Yanfeng Liu
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Weixi Zhao
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Peter M. Glazer
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Yuan Liu
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Michael D. Sevilla
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Amitava Adhikary
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States
| | - Stanislaw F. Wnuk
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
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12
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Barkam S, Ortiz J, Saraf S, Eliason N, Mccormack R, Das S, Gupta A, Neal C, Petrovici A, Hanson C, Sevilla MD, Adhikary A, Seal S. Modulating the Catalytic Activity of Cerium Oxide Nanoparticles with the Anion of the Precursor Salt. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:20039-20050. [PMID: 28936278 PMCID: PMC5602578 DOI: 10.1021/acs.jpcc.7b05725] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In this work, we tested our hypothesis that surface chemistry and antioxidant properties of cerium nanoparticles (CNPs) are affected by presence of counterions. We first employed various precursor cerium (III) (Ce(III)) salts with different counterions (acetate, nitrate, chloride, sulfate) to synthesize CNPs following the same wet chemical methodology. Electron spin resonance (ESR) studies provided evidence for the formation of radicals from counterions (e.g., NO3•2- from reduction of NO3- in CNPs synthesized from Ce(III) nitrate). Physicochemical properties of these CNPs, e.g., dispersion stability, hydrodynamic size, signature surface chemistry, SOD-mimetic activity, and oxidation potentials were found to be significantly affected by the anions of the precursor salts. CNPs synthesized from Ce(III) nitrate and Ce(III) chloride exhibited higher extent of SOD-mimetic activities. Therefore, these CNPs were studied extensively employing in-situ UV-Visible spectroelectrochemistry and changing the counterion concentrations affected the oxidation potentials of these CNPs. Thus, the physicochemical and antioxidant properties of CNPs can be modulated by anions of the precursor. Furthermore, our ESR studies present evidence of the formation of guanine cation radical (G•+) in 5'-dGMP via UV-photoionization at 77 K in the presence of CNPs synthesized from Ce(III) nitrate and chloride and CNPs act as the scavenger of radiation-produced electrons.
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Affiliation(s)
- Swetha Barkam
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Julian Ortiz
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Shashank Saraf
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Nicholas Eliason
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Rameech Mccormack
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Soumen Das
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
- NanoScience Technology Center (NSTC), Materials Science Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Ankur Gupta
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Craig Neal
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
| | - Alex Petrovici
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, MI – 48309, USA
| | - Cameron Hanson
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, MI – 48309, USA
| | - Michael D. Sevilla
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, MI – 48309, USA
| | - Amitava Adhikary
- Department of Chemistry, 146 Library Drive, Oakland University, Rochester, MI – 48309, USA
- Corresponding authors: Prof. Amitava Adhikary, , Telephone: 248-370-2094, Fax: 248-370-2321; Prof. Sudipta Seal, , Telephone: 407-823-5277 or 407-882-1458, Fax: 407-882-1156 or 407-823-0208
| | - Sudipta Seal
- Advanced Materials Processing and Analysis Center (AMPAC), Materials Science and Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
- NanoScience Technology Center (NSTC), Materials Science Engineering (MSE), University of Central Florida, 4000, Central Florida Boulevard, Orlando, Fl – 32816, USA
- College of Medicine, University of Central Florida, 6850 Lake Nona Blvd, Orlando, FL – 32827, USA
- Corresponding authors: Prof. Amitava Adhikary, , Telephone: 248-370-2094, Fax: 248-370-2321; Prof. Sudipta Seal, , Telephone: 407-823-5277 or 407-882-1458, Fax: 407-882-1156 or 407-823-0208
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