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Trzcionka J, Lhiaubet-Vallet V, Paris C, Belmadoui N, Climent MJ, Miranda MA. Model Studies on a Carprofen Derivative as Dual Photosensitizer for Thymine Dimerization and (6–4) Photoproduct Repair. Chembiochem 2007; 8:402-7. [PMID: 17285658 DOI: 10.1002/cbic.200600394] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cyclobutane pyrimidine dimers (CPD) and (6-4) photoproducts are among the main UV-induced DNA lesions. Both types of damage are mostly repaired in prokaryotes by photolyase enzymes. The repair mechanism of (6-4) photolyases has still not been fully elucidated, but it is assumed that back rearrangement to the oxetane occurs prior to repair. In this work, a non-steroidal anti-inflammatory drug derivative corresponding to the dechlorinated methyl ester of carprofen (namely methyl 2-(carbazol-2-yl)propanoate, PPMe) has been used to achieve the photosensitized cycloreversion of model oxetanes (formally resulting from photocycloaddition between benzophenone and 1,3-dimethylthymine or 2'-deoxyuridine), by employing fluorescence spectroscopy, laser flash photolysis, HPLC and NMR. Although PPMe is able to photoinduce the cycloreversion of both oxetanes, the fluorescence quenching of PPMe is faster for the 2'-deoxyribose-containing oxetane; this underlines the importance of the structure in such studies. Moreover, PPMe was shown to photoinduce the formation of thymidine cyclobutane dimers through a triplet-triplet energy transfer from a vibrationally excited state, as suggested by the enhanced PPMe triplet quenching by thymidine with increasing temperature. These results reveal a dual role of PPMe in DNA photosensitization, in that it photoinduces either damage or repair.
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Affiliation(s)
- Jérôme Trzcionka
- Instituto de Tecnología Química UPV-CSIC, Departamento de Química, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain
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52
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Hare PM, Crespo-Hernández CE, Kohler B. Solvent-Dependent Photophysics of 1-Cyclohexyluracil: Ultrafast Branching in the Initial Bright State Leads Nonradiatively to the Electronic Ground State and a Long-Lived1nπ* State. J Phys Chem B 2006; 110:18641-50. [PMID: 16970494 DOI: 10.1021/jp064714t] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The modified nucleic acid base, 1-cyclohexyluracil, was studied by femtosecond transient absorption spectroscopy in protic and aprotic solvents of varying polarity. UV excitation at 267 nm populates the lowest-energy bright state, a (1)pipi* state, which has a lifetime of 120-270 fs, depending on the solvent. In all solvents, this initial bright state population bifurcates with approximately 60% undergoing subpicosecond nonradiative decay to the electronic ground state and the remaining population branching to a singlet dark state. The latter absorbs between 340 and 450 nm. The latter state is assigned to the lowest-energy (1)npi* state. It decays to the electronic ground state with a lifetime that varies from 26 ps in water to at least several nanoseconds in aprotic solvents. The results suggest that the two nonradiative decay pathways identified for photoexcited uracil in recent quantum chemical calculations (Matsika, S. J. Phys. Chem. A. 2004, 108, 7584) are simultaneously operative in a wide variety of solvent environments. The lowest-energy triplet state was also detected by transient absorption. The triplet population appears in a few picoseconds and is not formed from the thermalized (1)npi* state. It is suggested that high spin-orbit coupling is found only along initial segments of the nonradiative decay pathways. Efficient intersystem crossing prior to vibrational cooling offers a possible explanation for the wavelength-dependent triplet yields seen in single DNA bases.
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Affiliation(s)
- Patrick M Hare
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA
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53
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Bucher G, Lu C, Sander W. The Photochemistry of Lipoic Acid: Photoionization and Observation of a Triplet Excited State of a Disulfide. Chemphyschem 2005; 6:2607-18. [PMID: 16331730 DOI: 10.1002/cphc.200500211] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Under short-wavelength UV irradiation, lipoic acid (LipSS) and its reduced form, dihydrolipoic acid (DHLA), undergo photoionization processes through a bi- or monophotonic pathway. After ionization, the LipSS radical cation (LipSS*+) and radical anion (LipSS*-) are generated. LipSS*- can be converted to equimolar amounts of LipSS and DHLA through second-order decay. Triplet acetone can be quenched by LipSS and DHLA with a rate close to the diffusion-controlled limit. The mechanism was further confirmed by continuous irradiation experiments. When LipSS is directly irradiated with UVA light, the first excited triplet state of LipSS is observed, with a lifetime tau=75 ns. Characteristic reactions include triplet energy transfer to oxygen and beta-carotene and addition to isoprene. The lifetime of triplet LipSS is also shortened by addition of water and methanol.
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Affiliation(s)
- Götz Bucher
- Lehrstuhl für Organische Chemie II, Ruhr-Universität, 44780 Bochum, Germany.
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54
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Gutierrez F, Trzcionka J, Deloncle R, Poteau R, Chouini-Lalanne N. Absorption and solvatochromic properties of 2-methylisoindolin-1-one and related compounds: interplay between theory and experiments. NEW J CHEM 2005. [DOI: 10.1039/b415876h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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55
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Lhiaubet-Vallet V, Trzcionka J, Encinas S, Miranda MA, Chouini-Lalanne N. The Triplet State of a N-Phenylphthalimidine with High Intersystem Crossing Efficiency: Characterization by Transient Absorption Spectroscopy and DNA Sensitization Properties. J Phys Chem B 2004. [DOI: 10.1021/jp0498926] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Virginie Lhiaubet-Vallet
- Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain and Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, UMR 5623 au CNRS, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
| | - Jérôme Trzcionka
- Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain and Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, UMR 5623 au CNRS, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
| | - Susana Encinas
- Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain and Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, UMR 5623 au CNRS, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
| | - Miguel A. Miranda
- Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain and Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, UMR 5623 au CNRS, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
| | - Nadia Chouini-Lalanne
- Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain and Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, UMR 5623 au CNRS, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
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56
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Marquez C, Pischel U, Nau WM. Selective fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene by nucleotides. Org Lett 2004; 5:3911-4. [PMID: 14535741 DOI: 10.1021/ol035454q] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by nucleotides has been studied. The quenching mechanism was analyzed on the basis of deuterium isotope effects, tendencies for exciplex formation, and the quenching efficiency in the presence of a molecular container (cucurbit[7]uril). Exciplex-induced quenching appears to prevail for adenosine, cytidine, and uridine, while hydrogen abstraction becomes competitive for thymidine and guanosine. Compared to other fluorescent probes, DBO responds very selectively to the type of nucleotide.
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Affiliation(s)
- Cesar Marquez
- School of Engineering and Science, International University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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57
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Crespo-Hernández CE, Cohen B, Hare PM, Kohler B. Ultrafast Excited-State Dynamics in Nucleic Acids. Chem Rev 2004; 104:1977-2019. [PMID: 15080719 DOI: 10.1021/cr0206770] [Citation(s) in RCA: 962] [Impact Index Per Article: 48.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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58
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59
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Starikov E. Quantum chemistry of nucleic acids: how it could help and when it is necessary. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2002. [DOI: 10.1016/s1389-5567(02)00024-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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60
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Lindqvist L, Czochralska B, Fontaine-Aupart MP, Kawczynski W, Tfibel F, Douki T. Photochemistry of 2-chloropyrimidine. Photochem Photobiol Sci 2002; 1:600-6. [PMID: 12659505 DOI: 10.1039/b203620g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photochemistry of 2-chloropyrimidine (ClPy) was investigated by means of nanosecond laser flash photolysis, HPLC, mass spectrometry, polarography and absorption spectroscopy. Two major products were formed on low-intensity UV irradiation (lambda = 254 nm) of ClPy in anaerobic aqueous solution: 2-hydroxypyrimidine (quantum yield approximately 0.01) and a compound identified as 2-chloro-4,2'-bipyrimidine (quantum yield approximately 0.005). Only the former of these products was obtained under aerobic conditions. Investigation by nanosecond flash photolysis revealed the occurrence of efficient intersystem crossing to the ClPy triplet state; the deactivation processes from this state were determined. Photosensitised generation of the ClPy triplet state showed that the triplet is involved in the formation of the bipyrimidine. A reaction scheme is proposed comprising two reaction channels: heterolytic rupture of the C-Cl bond in the excited singlet state of ClPy leading to formation of 2-hydroxypyrimidine, and homolytic C-Cl rupture in the triplet state with creation of pyrimidinyl radicals, which react with excess ClPy to give 2-chloro-4,2'-bipyrimidine.
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Affiliation(s)
- Lars Lindqvist
- Laboratoire de Photophysique Moleculaire du CNRS, Bât. 210, Université Paris-Sud, 91405 Orsay, France.
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61
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Lhiaubet V, Paillous N, Chouini-Lalanne N. Comparison of DNA damage photoinduced by ketoprofen, fenofibric acid and benzophenone via electron and energy transfer. Photochem Photobiol 2001; 74:670-8. [PMID: 11723794 DOI: 10.1562/0031-8655(2001)074<0670:coddpb>2.0.co;2] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ketoprofen (KP) and fenofibrate, respectively, anti-inflammatory and hypolipidemiant agents, promote anormal photosensitivity in patients and may induce photoallergic cross-reactions correlated to their benzophenone-like structure. Here, their ability to photosensitize the degradation of biological targets was particularly investigated in DNA. The photosensitization of DNA damage by KP and fenofibric acid (FB), the main metabolite of fenofibrate, and their parent compound, benzophenone (BZ), was examined on a 32P-end-labeled synthetic oligonucleotide in phosphate-buffered solution using gel sequencing experiments. Upon irradiation at lambda > 320 nm, piperidine-sensitive lesions were induced in single-stranded oligonucleotides by KP, FB and BZ at all G sites to the same extent. This pattern of damage, enhanced in D2O is characteristic of a Type-II mechanism. Spin trapping experiments using 2,2,6,6-tetramethyl-4-piperidone have confirmed the production of singlet oxygen during drug photolysis. On double-stranded oligonucleotides, highly specific DNA break occurred selectively at 5'-G of a 5'-GG-3' sequence, after alkali treatment. Prolonged irradiation led to the degradation of all G residues, with efficiency decreasing in the order 5'-GG > 5'-GA > 5'-GC > 5'-GT, in good agreement with the calculated lowest ionization potentials of stacked nucleobase models supporting the assumption of a Type-I mechanism involving electron transfer, also observed to a lesser extent with adenine. Cytosine sites were also affected but the action of mannitol which selectively inhibited cytosine lesions suggests, in this case, the involvement of hydroxyl radical, also detected by electronic paramagnetic resonance using 5,5-dimethyl-1-pyrrolidine-1-oxide as spin trap. On a double-stranded 32P-end-labeled 25-mer oligonucleotide containing TT and TTT sequences, the three compounds were found to photosensitize by triplet-triplet energy transfer the formation of cyclobutane thymine dimers detected using T4 endonuclease V.
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Affiliation(s)
- V Lhiaubet
- Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique, Université Paul Sabatier, Toulouse, France
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62
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Görner H, Griesbeck AG, Heinrich T, Kramer W, Oelgemöller M. Time-resolved spectroscopy of sulfur- and carboxy-substituted N-alkylphthalimides. Chemistry 2001; 7:1530-8. [PMID: 11330909 DOI: 10.1002/1521-3765(20010401)7:7<1530::aid-chem1530>3.0.co;2-l] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The photophysical and photochemical properties of N-phthaloyl-methionine (1), S-methyl-N-phthaloyl-cysteine methyl ester (2) and N-phthaloyltranexamic acid (3) were studied by time-resolved UV/Vis spectroscopy, using laser pulses at 248 or 308 nm. The quantum yield of fluorescence is low (phi(f)< 10(-2)) for 1-3 in fluid and glassy media, whereas that of phosphorescence is large (0.3-0.5) in ethanol at - 196 degrees C. The triplet properties were examined in several solvents, at room temperature and below. The spectra and decay kinetics are similar, but the population of the pi(pi*) triplet state, as measured by T-T absorption, is much lower for 1 and 2 than for 3 or N-methyltrimellitimide (5') at ambient temperatures. The quantum yield (phi(delta)) of singlet molecular oxygen O2(1deltag) formation is substantial for 3 and 5' in several air- or oxygen-saturated solvents at room temperature, but small for 2 and 1. The quantum yield of decomposition is substantial (0.2-0.5) for 3 and small (<0.05) for 2 and 1. It is postulated that photoinduced charge separation in the spectroscopically undetectable 3n,pi* state may account for the cyclization products of 1 and 2. In aqueous solution, this also applies for 3, whereas in organic solvents cyclization involves mainly the lower lying 3pi,(pi*) state. Triplet acetone, acetophenone and xanthone are quenched by 1-3 in acetonitrile; the rate constant is close to the diffusion-controlled limit, but smaller for benzophenone. While the energy transfer from the triplet ketone occurs for 3, a major contribution of electron transfer to the N-phthalimide derivative is suggested for 1 and 2, where the radical anion of benzophenone or 4-carboxybenzophenone is observed in alkaline aqueous solution.
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Affiliation(s)
- H Görner
- Max-Planck-Institut für Strahlenchemie, Mülheim an der Ruhr, Germany
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63
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For�s M, Duran M, Sol� M, Adamowicz L. Theoretical characterization of intramolecular proton transfer in the ground and the lowest-lying triplet excited states of 1-amino-3-propenal: a methodological comparison. J Comput Chem 2000. [DOI: 10.1002/(sici)1096-987x(200003)21:4<257::aid-jcc2>3.0.co;2-f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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64
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Griesbeck AG, Görner H. Laser flash photolysis study of N-alkylated phthalimides. J Photochem Photobiol A Chem 1999. [DOI: 10.1016/s1010-6030(99)00180-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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65
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Lomoth R, Naumov S, Brede O. Transients of the Oxidation of Pyrimidines with SO4•-: Structure and Reactivity of the Resulting Radicals. J Phys Chem A 1999. [DOI: 10.1021/jp990777i] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. Lomoth
- University of Leipzig, Interdisciplinary Group for Time-Resolved Spectroscopy, Permoserstr. 15, D-04303 Leipzig, Germany
| | - S. Naumov
- University of Leipzig, Interdisciplinary Group for Time-Resolved Spectroscopy, Permoserstr. 15, D-04303 Leipzig, Germany
| | - O. Brede
- University of Leipzig, Interdisciplinary Group for Time-Resolved Spectroscopy, Permoserstr. 15, D-04303 Leipzig, Germany
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66
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Douki T, Perdiz D, Grof P, Kuluncsics Z, Moustacchi E, Cadet J, Sage E. Oxidation of Guanine in Cellular DNA by Solar UV Radiation: Biological Role. Photochem Photobiol 1999. [DOI: 10.1111/j.1751-1097.1999.tb07988.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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67
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Turro C, Hall DB, Chen W, Zuilhof H, Barton JK, Turro NJ. Solution Photoreactivity of Phenanthrenequinone Diimine Complexes of Rhodium and Correlations with DNA Photocleavage and Photooxidation. J Phys Chem A 1998. [DOI: 10.1021/jp981013q] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Claudia Turro
- Department of Chemistry, Columbia University, New York, New York 10027, and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Daniel B. Hall
- Department of Chemistry, Columbia University, New York, New York 10027, and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Wei Chen
- Department of Chemistry, Columbia University, New York, New York 10027, and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Han Zuilhof
- Department of Chemistry, Columbia University, New York, New York 10027, and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Jacqueline K. Barton
- Department of Chemistry, Columbia University, New York, New York 10027, and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Nicholas J. Turro
- Department of Chemistry, Columbia University, New York, New York 10027, and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
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68
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Song Q, Lin W, Yao S, Lin N. Comparative studies of triplet states of thymine components by acetone sensitization and direct excitation in aqueous solution at room temperature. J Photochem Photobiol A Chem 1998. [DOI: 10.1016/s1010-6030(98)00219-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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69
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Mohtat N, Cozens FL, Hancock-Chen T, Scaiano JC, McLean J, Kim J. Magnetic Field Effects on the Behavior of Radicals in Protein and DNA Environments. Photochem Photobiol 1998. [DOI: 10.1111/j.1751-1097.1998.tb05173.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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70
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71
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Herrlich P, Blattner C, Knebel A, Bender K, Rahmsdorf HJ. Nuclear and non-nuclear targets of genotoxic agents in the induction of gene expression. Shared principles in yeast, rodents, man and plants. Biol Chem 1997; 378:1217-29. [PMID: 9426181 DOI: 10.1515/bchm.1997.378.11.1217] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The interplay between environmental cues and the genetic response is decisive for the development, health and well-being of an organism. For some environmental factors a narrow margin separates beneficial and toxic impacts. With the increasing exposure to UV-B this dichotomy has reached public attention. This review will be concerned with the mechanisms that mediate a cellular genetic response to noxious agents. The toxic stimuli find access to the regulatory network inside cells by interacting at several points with cellular molecules - a process that converts the 'outside information' into 'cellular language'. As a consequence of such interactions, many adverse agents cause massive signal transduction and changes of gene expression. There is an interesting conservation of the mechanisms from yeast to man. An understanding of the genetic programs and of their phenotypic consequences is lagging behind.
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Affiliation(s)
- P Herrlich
- Forschungszentrum Karlsruhe, Institut für Genetik and Universität Karlsruhe, Germany
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72
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Song QH, Yao SD, Lin NY. Laser-induced modification of DNA and Poly[A,G] at guanine moiety using acetone as photosensitizer. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 40:199-203. [PMID: 9463112 DOI: 10.1016/s1011-1344(97)00051-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The interactions of triplet acetone with polyadenylic acid (Poly[A]), polyguanylic acid (Poly[G]), polyadenylic-guanylic acid (Poly[A,G]) and single-stranded DNA (ssDNA) were investigated in neutral aqueous solution using KrF (248 nm) laser flash photolysis. The transient absorption spectra and kinetics of DNA and polynucleotides obtained under acetone sensitization demonstrated that the predominant transient species was guanine radical. These novel findings have offered time-resolved evidence for photochemical modification of DNA and Poly[A,G] at guanine moiety.
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Affiliation(s)
- Q H Song
- Laboratory of Radiation Chemistry, Shanghai Institute of Nuclear Research, Academia Sinica, People's Republic of China
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73
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Greenberg MM, Barvian MR, Cook GP, Goodman BK, Matray TJ, Tronche C, Venkatesan H. DNA Damage Induced via 5,6-Dihydrothymid-5-yl in Single-Stranded Oligonucleotides. J Am Chem Soc 1997. [DOI: 10.1021/ja9533510] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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74
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Barone V, Adamo C. Proton transfer in the ground and lowest excited states of malonaldehyde: A comparative density functional and post‐Hartree–Fock study. J Chem Phys 1996. [DOI: 10.1063/1.472900] [Citation(s) in RCA: 190] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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75
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Cook GP, Greenberg MM. A Novel Mechanism for the Formation of Direct Strand Breaks upon Anaerobic Photolysis of Duplex DNA Containing 5-Bromodeoxyuridine. J Am Chem Soc 1996. [DOI: 10.1021/ja960652g] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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