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Sarlauskas J, Tulaite K, Tamuliene J. Investigation of oxygen influence to the optical properties of tirapazamine. J Mol Model 2022; 28:96. [PMID: 35320419 DOI: 10.1007/s00894-022-05085-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/08/2022] [Indexed: 11/27/2022]
Abstract
New data on 3-amino-1,2,4-benzotriazine 1,4-dioxide (tirapazamine) fluorescence has been obtained using the Perkin-Elmer Lambda 950 UV-Vis-NIR spectrophotometer experimental technique in combination with the extensive DFT-theory approach. Based on the results obtained, we revealed that the optical properties of the molecule under study remain significantly unchanged when the number of oxygen substitutions decreases from 2 to 0. Here we also present the results of the study of the influence of acetonitrile and ethyl acetate on the fluorescence of tirapazamine with the different number of oxygen atoms. Results of our investigation indicate the formation of anion in the case of 3-amino-1,2,4-benzotriazine 1,4-dioxide with two oxygen atoms and their transformation to tirapazamine with one oxygen atom.
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Affiliation(s)
- Jonas Sarlauskas
- Life Sciences Centre, Institute of Biochemistry, Vilnius University, Sauletekio av. 7, Vilnius, Lithuania
| | - Kamile Tulaite
- Vilnius University Institute of Photonics and Nanotechnology, Faculty of Physics, Vilnius University, Sauletekio av. 3, 10257, Vilnius, Lithuania
| | - Jelena Tamuliene
- Institute of Theoretical Physics and Astronomy, Vilnius University, Sauletekio av. 3, Vilnius, Lithuania.
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2
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Silva VL, Kaassis A, Dehsorkhi A, Koffi CR, Severic M, Abdelhamid M, Nyimanu D, Morris CJ, Al-Jamal WT. Enhanced selectivity, cellular uptake, and in vitro activity of an intrinsically fluorescent copper-tirapazamine nanocomplex for hypoxia targeted therapy in prostate cancer. Biomater Sci 2020; 8:2420-2433. [PMID: 32236169 DOI: 10.1039/c9bm01905g] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In the present work, a copper-tirapazamine (TPZ) nanocomplex [Cu(TPZ)2] was synthesized for selective hypoxia-targeted therapy. The nanocomplex revealed a crystalline form, and exhibited higher lipophilicity, compared to TPZ. Furthermore, its stability was confirmed in different media, with minimum dissociation in serum (∼20% up to 72 h). In contrast to other hypoxia-targeted agents, our intrinsically fluorescent nanocomplex offered an invaluable tool to monitor its cellular uptake and intracellular distribution under both normoxia and hypoxia. The conferred higher cellular uptake of the nanocomplex, especially under hypoxia, and its biocompatible reductive potential resulted in superior hypoxia selectivity in two prostate cancer (PC) cell lines. More promisingly, the nanocomplex showed higher potency in three-dimensional tumor spheroids, compared to TPZ, due to its slower metabolism, and probably deeper penetration in tumor spheroids. Interestingly, the nuclear localization of the intact nanocomplex, combined with its higher DNA binding affinity, as evidenced by the DNA binding assay, resulted in significant S-phase cell-cycle arrest, followed by apoptosis in the three-dimensional spheroid model. In conclusion, the presented findings suggested that the Cu(TPZ)2 nanocomplex can be a promising hypoxia-targeted therapeutic, which could potentiate the efficacy of the existing chemo- and radiotherapy in PC.
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Affiliation(s)
- Vera L Silva
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
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3
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Shen X, Laber CH, Sarkar U, Galazzi F, Johnson KM, Mahieu NG, Hillebrand R, Fuchs-Knotts T, Barnes CL, Baker GA, Gates KS. Exploiting the Inherent Photophysical Properties of the Major Tirapazamine Metabolite in the Development of Profluorescent Substrates for Enzymes That Catalyze the Bioreductive Activation of Hypoxia-Selective Anticancer Prodrugs. J Org Chem 2018; 83:3126-3131. [DOI: 10.1021/acs.joc.7b03035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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4
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Liu Q, Lei Z, Huang A, Lu Q, Wang X, Ahmed S, Awais I, Yuan Z. Mechanisms of the Testis Toxicity Induced by Chronic Exposure to Mequindox. Front Pharmacol 2017; 8:679. [PMID: 29018347 PMCID: PMC5622959 DOI: 10.3389/fphar.2017.00679] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 09/11/2017] [Indexed: 12/12/2022] Open
Abstract
Mequindox (MEQ) is a synthetic antimicrobial agent widely used in China since the 1980s. Although the toxicity of MEQ is well recognized, its testis toxicity has not been adequately investigated. In the present study, we provide evidence that MEQ triggers oxidative stress, mitochondrion dysfunction and spermatogenesis deficiency in mice after exposure to MEQ (0, 25, 55, and 110 mg/kg in the diet) for up to 18 months. The genotoxicity and adrenal toxicity may contribute to sperm abnormalities caused by MEQ. Moreover, using LC/MS-IT-TOF analysis, two metabolites, 3-methyl-2-(1-hydroxyethyl) quinoxaline-N4-monoxide (M4) and 3-methyl-2-(1-hydroxyethyl) quinoxaline-N1-monoxide (M8), were detected in the serum of mice, which directly confirms the relationship between the N→O group reduction metabolism of MEQ and oxidative stress. Interestingly, only M4 was detected in the testes, suggesting that the higher reproductive toxicity of M4 than M8 might be due to the increased stability of M4-radical (M4-R) compared to M8-radical (M8-R). Furthermore, the expression of the blood-testis barrier (BTB)-associated junctions such as tight junctions, gap junctions and basal ectoplasmic specializations were also examined. The present study demonstrated for the first time the role of the M4 in testis toxicity, and illustrated that the oxidative stress, mitochondrion dysfunction and interference in spermatogenesis, as well as the altered expression of BTB related junctions, were involved in the reproductive toxicity mediated by MEQ in vivo.
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Affiliation(s)
- Qianying Liu
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Wuhan, China
| | - Zhixin Lei
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China
| | - Anxiong Huang
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China
| | - Qirong Lu
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, China
| | - Xu Wang
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, China
| | - Saeed Ahmed
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China
| | - Ihsan Awais
- Department of Biosciences, COMSATS Institute of Information Technology, Sahiwal, Pakistan
| | - Zonghui Yuan
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Wuhan, China.,MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China.,Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, China
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5
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Toxic metabolites, MAPK and Nrf2/Keap1 signaling pathways involved in oxidative toxicity in mice liver after chronic exposure to Mequindox. Sci Rep 2017; 7:41854. [PMID: 28157180 PMCID: PMC5291092 DOI: 10.1038/srep41854] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 12/30/2016] [Indexed: 12/21/2022] Open
Abstract
Mequindox (MEQ) is a synthetic antimicrobial agent of quinoxaline-1,4-dioxide group (QdNOs). The liver is regarded as the toxicity target of QdNOs, and the role of N → O group-associated various toxicities mediated by QdNOs is well recognized. However, the mechanism underlying the in vivo effects of MEQ on the liver, and whether the metabolic pathway of MEQ is altered in response to the pathophysiological conditions still remain unclear. We now provide evidence that MEQ triggers oxidative damage in the liver. Moreover, using LC/MS-ITTOF analysis, two metabolites of MEQ were detected in the liver, which directly confirms the potential connection between N → O group reduction metabolism of MEQ and liver toxicity. The gender difference in MEQ-induced oxidative stress might be due to adrenal toxicity and the generation of M4 (2-isoethanol 1-desoxymequindox). Furthermore, up-regulation of the MAPK and Nrf2-Keap1 family and phase II detoxifying enzymes (HO-1, GCLC and NQO1) were also observed. The present study demonstrated for the first time the protein peroxidation and a proposal metabolic pathway after chronic exposure of MEQ, and illustrated that the MAPK, Nrf2-Keap1 and NF-кB signaling pathways, as well as the altered metabolism of MEQ, were involved in oxidative toxicity mediated by MEQ in vivo.
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Liu Q, Zhang J, Luo X, Ihsan A, Liu X, Dai M, Cheng G, Hao H, Wang X, Yuan Z. Further investigations into the genotoxicity of quinoxaline-di-N-oxides and their primary metabolites. Food Chem Toxicol 2016; 93:145-57. [PMID: 27170491 DOI: 10.1016/j.fct.2016.04.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/26/2016] [Accepted: 04/28/2016] [Indexed: 12/15/2022]
Abstract
Quinoxaline-di-N-oxides (QdNOs) are potential antibacterial agents with a wide range of biological properties. Quinocetone (QCT), carbadox (CBX), olaquindox (OLA), mequindox (MEQ) and cyadox (CYA) are classical QdNOs. Though the genotoxicity of parent drugs has been evaluated, the genotoxicity of their primary N → O reduced metabolites remains unclear. In the present study, a battery of four different short-term tests, mouse lymphoma assay (MLA), Ames test, chromosomal aberration assay in vitro and bone marrow erythrocyte micronucleus assay in vivo was carried out to investigate the genotoxicity of the six primary N → O reduced metabolites. Additionally, the genotoxicity of five parent drugs was evaluated by the MLA. Strong genotoxicity of N1-MEQ, B-MEQ and B-CBX was found in three of the assays but not in the Ames assay, and the rank order was N1-MEQ>B-MEQ>B-CBX that is consistent with prototype QdNOs. Negative results for the five QdNOs were noted in the MLA. We present for the first time a comparison of the genotoxicity of primary N → O reduced metabolites, and evaluate the ability of five QdNOs to cause mutations in the MLA. The present study demonstrates that metabolites are involved in genetic toxicity mediated by QdNOs, and improve the prudent use of QdNOs for public health.
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Affiliation(s)
- Qianying Liu
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jianwu Zhang
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Xun Luo
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Awais Ihsan
- Department of Biosciences, COMSATS Institute of Information Technology, Sahiwal, Pakistan
| | - Xianglian Liu
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Menghong Dai
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, Hubei, China
| | - Guyue Cheng
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, Hubei, China
| | - Haihong Hao
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, Hubei, China
| | - Xu Wang
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, Hubei, China.
| | - Zonghui Yuan
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, Hubei 430070, China; MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, Hubei, China.
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7
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Gu Y, Jaiswal JK, Wang J, Hicks KO, Hay MP, Wilson WR. Photodegradation of the benzotriazine 1,4-Di-N-oxide hypoxia-activated prodrug SN30000 in aqueous solution. J Pharm Sci 2014; 103:3464-3472. [PMID: 25212501 DOI: 10.1002/jps.24099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/09/2014] [Accepted: 06/30/2014] [Indexed: 01/31/2023]
Abstract
SN30000 is a benzotriazine di-N-oxide which is selectively toxic to radio-resistant hypoxic cells in tumours. Given the complex photochemistry of some aromatic N-oxides, we evaluated the potential for photodegradation of SN30000 solutions. Initial studies demonstrated significant oxygen-insensitive degradation under normal laboratory lighting conditions. The kinetics of photodegradation showed marked concentration dependence of the form predicted by Beer's law, with a quantum yield of 0.016. The photoproducts could be rationalised as arising from an oxaziridine intermediate. The major stable product (cmpd 6; yield ∼50% of SN30000 loss under either UV or visible light) was characterised as resulting from intra-molecular oxygen transfer to the morpholine side chain of SN30000. This mechanism is consistent with lack of formation of the corresponding morpholine N-oxide from an analogue (SN29751) in which the proposed six-membered-ring transition state cannot form. Cmpd 6 was less cytotoxic than SN30000 to human tumour cells in culture, under either hypoxic or aerobic conditions, and was not toxic when administered intra-peritoneally to NIH-III nude mice at a dose (750 μmol/kg) above the maximal tolerated dose of SN30000 itself. In conclusion, SN30000 solutions are significantly photosensitive at low concentration, requiring protection from light, but the major photoproduct is less toxic than the parent.
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Affiliation(s)
- Yongchuan Gu
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Jagdish K Jaiswal
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Jingli Wang
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Kevin O Hicks
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Michael P Hay
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - William R Wilson
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
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8
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Evaluation of different PAMAM dendrimers as molecular vehicle of 1,2,4-triazine N-oxide derivative with potential antitumor activity. J INCL PHENOM MACRO 2013. [DOI: 10.1007/s10847-013-0324-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Junnotula V, Sarkar U, Sinha S, Gates KS. Initiation of DNA strand cleavage by 1,2,4-benzotriazine 1,4-dioxide antitumor agents: mechanistic insight from studies of 3-methyl-1,2,4-benzotriazine 1,4-dioxide. J Am Chem Soc 2009; 131:1015-24. [PMID: 19117394 PMCID: PMC2819123 DOI: 10.1021/ja8049645] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The antitumor agent 3-amino-1,2,4-benzotriazine 1,4-dioxide (tirapazamine, TPZ, 1) gains medicinal activity through its ability to selectively damage DNA in the hypoxic cells found inside solid tumors. This occurs via one-electron enzymatic reduction of TPZ to yield an oxygen-sensitive drug radical (2) that leads to oxidatively generated DNA damage under hypoxic conditions. Two possible mechanisms have been considered to account for oxidatively generated DNA damage by TPZ. First, homolysis of the N-OH bond in 2 may yield the well-known DNA-damaging agent, hydroxyl radical. Alternatively, it has been suggested that elimination of water from 2 generates a benzotriazinyl radical (4) as the ultimate DNA-damaging species. In the studies described here, the TPZ analogue 3-methyl-1,2,4-benzotriazine 1,4-dioxide (5) was employed as a tool to probe the mechanism of DNA damage within this new class of antitumor drugs. Initially, it was demonstrated that 5 causes redox-activated, hypoxia-selective oxidation of DNA and small organic substrates in a manner that is completely analogous to TPZ. This suggests that 5 and TPZ damage DNA by the same chemical mechanism. Importantly, the methyl substituent in 5 provides a means for assessing whether the putative benzotriazinyl intermediate 7 is generated following one-electron reduction. Two complementary isotopic labeling experiments provide evidence against the formation of the benzotriazinyl radical intermediate. Rather, a mechanism involving the release of hydroxyl radical from the activated drug radical intermediates can explain the DNA-cleaving properties of this class of antitumor drug candidates.
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Affiliation(s)
- Venkatraman Junnotula
- University of Missouri–Columbia, Departments of Chemistry and Biochemistry, 125 Chemistry Building, Columbia, MO 65211
| | - Ujjal Sarkar
- University of Missouri–Columbia, Departments of Chemistry and Biochemistry, 125 Chemistry Building, Columbia, MO 65211
| | - Sarmistha Sinha
- University of Missouri–Columbia, Departments of Chemistry and Biochemistry, 125 Chemistry Building, Columbia, MO 65211
| | - Kent S. Gates
- University of Missouri–Columbia, Departments of Chemistry and Biochemistry, 125 Chemistry Building, Columbia, MO 65211
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Villegas ML, Bertolotti SG, Previtali CM, Encinas MV. Reactions of Excited States of Phenoxazin-3-one Dyes with Amino Acids¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2005.tb01458.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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11
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Ylinen T, Suomi J, Helin M, Ala-Kleme T, Kulmala S. Time-Resolved Detection of Hot Electron-Induced Electrochemiluminescence of Fluorescein in Aqueous Solution. J Fluoresc 2006; 16:27-33. [PMID: 16496218 DOI: 10.1007/s10895-005-0023-2] [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] [Received: 07/01/2005] [Accepted: 10/14/2005] [Indexed: 10/25/2022]
Abstract
Strong electrogenerated chemiluminescence (ECL) of fluorescein is generated during cathodic pulse polarization of oxide-covered aluminum electrodes and the resulting decay of emission is so sluggish that time-resolved detection of fluorescein is feasible. The present ECL in aqueous solution is based on the tunnel emission of hot electrons into the aqueous electrolyte solution, which probably results in the generation of hydrated electrons and hydroxyl radicals acting as redox mediators. The successive one-electron redox steps with the primary radicals result in fluorescein in its lowest excited singlet state. The method allows the detection of fluorescein (or its derivatives containing usable linking groups to biomolecules) over several orders of magnitude of concentration with detection limits well below nanomolar concentration level. The detection limits can still be lowered, e.g., by addition of azide or bromide ions as coreactants. The results suggest that the derivatives of fluorescein, such as fluorescein isothiocyanate (FITC), can be detected by time-resolved measurements and thus be efficiently used as electrochemiluminescent labels in bioaffinity assays.
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Affiliation(s)
- Tiina Ylinen
- Laboratory of Analytical and Inorganic Chemistry, Helsinki University of Technology, Helsinki, P.O. Box 6100, FIN-02015 HUT, Finland
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Suomi J, Ylinen T, Håkansson M, Helin M, Jiang Q, Ala-Kleme T, Kulmala S. Hot electron-induced electrochemiluminescence of fluorescein in aqueous solution. J Electroanal Chem (Lausanne) 2006. [DOI: 10.1016/j.jelechem.2005.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Shi X, Poole JS, Emenike I, Burdzinski G, Platz MS. Time-Resolved Spectroscopy of the Excited Singlet States of Tirapazamine and Desoxytirapazamine. J Phys Chem A 2005; 109:1491-6. [PMID: 16833470 DOI: 10.1021/jp0457040] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Laser flash photolysis (LFP, 400 nm excitation) of the anti-cancer drug tirapazamine (TPZ) in acetonitrile produces the singlet excited-state S1 with lambda(max) = 544 nm. The lifetime of this state is 130 ps, in good agreement with the reported fluorescence lifetime. The excited state is reduced to the corresponding radical anion by KSCN or KI. The spectrum of the radical anion is in good agreement with previously reported pulse radiolysis studies and time-dependent density functional theory (TD-DFT) calculations. LFP of desoxytirapazamine (dTPZ) also produces the first excited singlet state, S1. The fluorescence quantum yield and lifetime (5.4 ns) of the dTPZ singlet excited state are both much greater than the corresponding values of TPZ. This is explained by DFT calculations that predict that cyclization of TPZ to form an oxaziridine is thermodynamically facile but that cyclization of dTPZ to form an oxadiaziridine is not. Thus, the S1 state of TPZ has a short lifetime and low fluorescence quantum yield due to ready cyclization whereas the cyclization of the S1 state of dTPZ is unimportant and does not limit either the fluorescence quantum yield or the fluorescence lifetime. This conclusion is confirmed by studies of dTPZ', an isomer of dTPZ containing the C=N-O moiety which has a low quantum yield and short fluorescence lifetime similar to that of TPZ.
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Affiliation(s)
- Xiaofeng Shi
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA
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14
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Villegas ML, Bertolotti SG, Previtali CM, Encinas MV. Reactions of Excited States of Phenoxazin-3-one Dyes with Amino Acids¶. Photochem Photobiol 2005. [DOI: 10.1562/2004-10-12-ra-342r1.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Brezová V, Dvoranová D, Kost'álová D. Oxygen activation by photoexcited protoberberinium alkaloids fromMahonia aquifolium. Phytother Res 2004; 18:640-6. [PMID: 15476305 DOI: 10.1002/ptr.1512] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protoberberinium salts, i.e. berberine (I), palmatine (II) and jatrorrhizine (III) prepared from Mahonia aquifolium (Pursh) Nutt. belong to isoquinoline alkaloids possessing interesting biological activity (e.g. antibacterial, antimalarial, antitumor). The characteristic UV/Vis absorption band maxima of I-III iodide salts were found in regions 350 and 425 nm in dimethylsulfoxide (DMSO) and ethanol solvents, and were only negligibly influenced by substitution changes on the C-2 and C-3 positions. The fluorescence intensity of protoberberinium salts monitored in ethanol solutions was significantly lowered by iodide counter-ions, and decreased in the order berberine > palmatine > jatrorrhizine. EPR spectroscopy supplied evidence of the formation of super-oxide anion radicals and singlet oxygen upon irradiation of berberine in oxygenated DMSO solvent. The photochemical generation of O(2) (.-) and (1)O(2) in DMSO solutions of palmatine and jatrorrhizine was substantially lower, and probably reflected the replacement of a photolabile methylenedioxy group at C-2 and C-3 positions in the berberine molecule by two methoxy groups in palmatine, and methoxyl (C-2) and hydroxyl (C-3) substitution in jatrorrhizine. Additionally, the powder EPR spectra of protoberberinium iodides I-III measured at 290 K revealed the presence of single-line EPR signals (g(eff) = 2.0044), which were attributed to hydroperoxidic structures produced by the autoxidation process. The photochemical reactions of protoberbenium salts producing reactive oxygen species after UVA excitation should be integrated in biological activity investigations, as well as in their applications in skin disorder treatment.
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Affiliation(s)
- Vlasta Brezová
- Department of Physical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37 Bratislava, Slovak Republic.
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Shi X, Platz MS. Time Resolved Spectroscopy of Some Aromatic N-Oxide Triplets, Radical Anions, and Related Radicals. J Phys Chem A 2004. [DOI: 10.1021/jp037708v] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaofeng Shi
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210
| | - Matthew S. Platz
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210
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17
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Birincioglu M, Jaruga P, Chowdhury G, Rodriguez H, Dizdaroglu M, Gates KS. DNA base damage by the antitumor agent 3-amino-1,2,4-benzotriazine 1,4-dioxide (tirapazamine). J Am Chem Soc 2003; 125:11607-15. [PMID: 13129365 DOI: 10.1021/ja0352146] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tirapazamine is a bioreductively activated DNA-damaging agent that selectively kills the hypoxic cells found in solid tumors. This compound shows clinical promise and is currently being examined in a variety of clinical trials, including several phase III studies. It is well established that DNA is an important cellular target for tirapazamine; however, the structural nature of the DNA damage inflicted by this drug remains poorly understood. As part of an effort to understand the chemical events responsible for the hypoxia-selective cytotoxicity of this drug, the studies reported here are designed to characterize tirapazamine-mediated damage to the genetic information stored in the heterocyclic base residues of double-stranded DNA. Here, we used gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry to characterize and quantify oxidative DNA base damage mediated by tirapazamine. A multiplicity of modified bases including 8,5'-cyclopurine-2'-deoxynucleoside tandem lesions were identified and quantified. The results provide the first detailed insight regarding the structural identity of the DNA base lesions caused by this drug. Interestingly, it appears that the hypoxic conditions under which tirapazamine operates, along with the unique chemical properties of the drug, yield a unique variety of DNA base damage that is dominated by formamidopyrimidine and 5-hydroxy-6-hydropyrimidine lesions. Importantly, the results suggest that tirapazamine may generate a set of poorly repaired, potentially cytotoxic DNA base lesions that block DNA transcription and replication. Overall, the results indicate that DNA base damage may contribute to the biological effects of tirapazamine in vivo.
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Affiliation(s)
- Mustafa Birincioglu
- Chemical Science and Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8311, USA
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