Harada, Y; Suzuki, T; Ichimura, T and Xu, YZ
(2007).
| DOI (Digital Object Identifier) Link: | https://doi.org/10.1021/jp0678094 |
|---|---|
| Google Scholar: | Look up in Google Scholar |
Abstract
Excited-state dynamics of 4-thiothymidine (S4-TdR) and its photosensitization to molecular oxygen in solution with UVA irradiation were investigated. Absorption and emission spectra measurements revealed that UVA photolysis of S4-TdR gives rise to a population of T1(*), following S2(*) f S1(n*) internal conversion. In transient absorption measurement, the 355 nm laser photolysis gave broad absorption (380-600 nm) bands of triplet S4-TdR. The time-resolved thermal lensing (TRTL) signal of S4-TdR containing the thermal component due to decay of triplet S4-TdR was clearly observed by the 355 nm laser excitation. The quantum yield for S1 f T1 intersystem crossing was estimated to be unity by a triplet quenching experiment with potassium iodide. In the presence of molecular oxygen, the photosensitization from triplet S4-TdR gave rise to singlet oxygen O2 (1g) with a quantum yield of 0.50. Therapeutic implications of such singlet oxygen formation are discussed.
| Item Type: | Article |
|---|---|
| ISSN: | 1520-6106 |
| Academic Unit/School: | Faculty of Science, Technology, Engineering and Mathematics (STEM) > Life, Health and Chemical Sciences Faculty of Science, Technology, Engineering and Mathematics (STEM) |
| Interdisciplinary Research Centre: | Biomedical Research Network (BRN) |
| Item ID: | 7709 |
| Depositing User: | Yao Xu |
| Date Deposited: | 23 May 2007 |
| Last Modified: | 04 Oct 2016 10:01 |
| URI: | http://oro.open.ac.uk/id/eprint/7709 |
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