Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization
β-Carbolines (βCs) are a group of alkaloids present in many plants and animals. It has been suggested that these alkaloids participate in a variety of significant photosensitized processes. Despite their well-established natural occurrence, the main biological role of these alkaloids and the mechani...
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2012
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paper:paper_14770520_v10_n9_p1807_Gonzalez2023-06-08T16:18:03Z Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization 8-oxo-7 ,8-dihydroguanine Carbolines Cyclobutane pyrimidine dimers DNA damages DNA-binding properties Electrostatic binding Harmane Kinetic analysis Photophysical Photoproducts Photoreactions Protonated Reactive oxygen species Repair enzymes Single-strand breaks Singlet oxygen Super oxide dismutase Superoxides Animals Binding energy Butane DNA Metabolites Nitrogen compounds Oxygen Pyridine Cesium carboline derivative DNA photosensitizing agent reactive oxygen metabolite thymidine article chemical structure chemistry kinetics photochemistry Carbolines DNA Kinetics Molecular Structure Photochemical Processes Photosensitizing Agents Reactive Oxygen Species Thymidine β-Carbolines (βCs) are a group of alkaloids present in many plants and animals. It has been suggested that these alkaloids participate in a variety of significant photosensitized processes. Despite their well-established natural occurrence, the main biological role of these alkaloids and the mechanisms involved are, to date, poorly understood. In the present work, we examined the capability of three important βCs (norharmane, harmane and harmine) and two of its derivatives (N-methyl-norharmane and N-methyl-harmane) to induce DNA damage upon UV-A excitation, correlating the type and extent of the damage with the photophysical characteristics and DNA binding properties of the compounds. The results indicate that DNA damage is mostly mediated by a direct type-I photoreaction of the protonated βCs after non-intercalative electrostatic binding. Reactive oxygen species such as singlet oxygen and superoxide are not involved to a major extent, as indicated by the only small influence of D 2O and of superoxide dismutase on damage generation. An analysis with repair enzymes revealed that oxidative purine modifications such as 8-oxo-7,8-dihydroguanine, sites of base loss and single-strand breaks (SSB) are generated by all βCs, while only photoexcited harmine gives rise to the formation of cyclobutane pyrimidine dimers as well. © 2012 The Royal Society of Chemistry. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14770520_v10_n9_p1807_Gonzalez http://hdl.handle.net/20.500.12110/paper_14770520_v10_n9_p1807_Gonzalez |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
8-oxo-7 ,8-dihydroguanine Carbolines Cyclobutane pyrimidine dimers DNA damages DNA-binding properties Electrostatic binding Harmane Kinetic analysis Photophysical Photoproducts Photoreactions Protonated Reactive oxygen species Repair enzymes Single-strand breaks Singlet oxygen Super oxide dismutase Superoxides Animals Binding energy Butane DNA Metabolites Nitrogen compounds Oxygen Pyridine Cesium carboline derivative DNA photosensitizing agent reactive oxygen metabolite thymidine article chemical structure chemistry kinetics photochemistry Carbolines DNA Kinetics Molecular Structure Photochemical Processes Photosensitizing Agents Reactive Oxygen Species Thymidine |
| spellingShingle |
8-oxo-7 ,8-dihydroguanine Carbolines Cyclobutane pyrimidine dimers DNA damages DNA-binding properties Electrostatic binding Harmane Kinetic analysis Photophysical Photoproducts Photoreactions Protonated Reactive oxygen species Repair enzymes Single-strand breaks Singlet oxygen Super oxide dismutase Superoxides Animals Binding energy Butane DNA Metabolites Nitrogen compounds Oxygen Pyridine Cesium carboline derivative DNA photosensitizing agent reactive oxygen metabolite thymidine article chemical structure chemistry kinetics photochemistry Carbolines DNA Kinetics Molecular Structure Photochemical Processes Photosensitizing Agents Reactive Oxygen Species Thymidine Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization |
| topic_facet |
8-oxo-7 ,8-dihydroguanine Carbolines Cyclobutane pyrimidine dimers DNA damages DNA-binding properties Electrostatic binding Harmane Kinetic analysis Photophysical Photoproducts Photoreactions Protonated Reactive oxygen species Repair enzymes Single-strand breaks Singlet oxygen Super oxide dismutase Superoxides Animals Binding energy Butane DNA Metabolites Nitrogen compounds Oxygen Pyridine Cesium carboline derivative DNA photosensitizing agent reactive oxygen metabolite thymidine article chemical structure chemistry kinetics photochemistry Carbolines DNA Kinetics Molecular Structure Photochemical Processes Photosensitizing Agents Reactive Oxygen Species Thymidine |
| description |
β-Carbolines (βCs) are a group of alkaloids present in many plants and animals. It has been suggested that these alkaloids participate in a variety of significant photosensitized processes. Despite their well-established natural occurrence, the main biological role of these alkaloids and the mechanisms involved are, to date, poorly understood. In the present work, we examined the capability of three important βCs (norharmane, harmane and harmine) and two of its derivatives (N-methyl-norharmane and N-methyl-harmane) to induce DNA damage upon UV-A excitation, correlating the type and extent of the damage with the photophysical characteristics and DNA binding properties of the compounds. The results indicate that DNA damage is mostly mediated by a direct type-I photoreaction of the protonated βCs after non-intercalative electrostatic binding. Reactive oxygen species such as singlet oxygen and superoxide are not involved to a major extent, as indicated by the only small influence of D 2O and of superoxide dismutase on damage generation. An analysis with repair enzymes revealed that oxidative purine modifications such as 8-oxo-7,8-dihydroguanine, sites of base loss and single-strand breaks (SSB) are generated by all βCs, while only photoexcited harmine gives rise to the formation of cyclobutane pyrimidine dimers as well. © 2012 The Royal Society of Chemistry. |
| title |
Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization |
| title_short |
Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization |
| title_full |
Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization |
| title_fullStr |
Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization |
| title_full_unstemmed |
Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization |
| title_sort |
photosensitization of dna by β-carbolines: kinetic analysis and photoproduct characterization |
| publishDate |
2012 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14770520_v10_n9_p1807_Gonzalez http://hdl.handle.net/20.500.12110/paper_14770520_v10_n9_p1807_Gonzalez |
| _version_ |
1768543052724436992 |