The Open UniversitySkip to content
 

Characteristics of the Excited Triplet States of Thiolated Guanosine Derivatives and Singlet Oxygen Generation

Miyata, Shoma; Tanabe, Shunsuke; Isozaki, Tasuku; Xu, Yao-Zhong and Suzuki, Tadashi (2018). Characteristics of the Excited Triplet States of Thiolated Guanosine Derivatives and Singlet Oxygen Generation. Photochemical & Photobiological Sciences, 17(10) pp. 1469–1476.

Full text available as:
[img]
Preview
PDF (Accepted Manuscript) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (2MB) | Preview
DOI (Digital Object Identifier) Link: https://doi.org/10.1039/C8PP00240A
Google Scholar: Look up in Google Scholar

Abstract

Thioguanine is sensitive to UVA light and generates singlet molecular oxygen (1O2*) when exposed to UVA. Three thioguanosine derivatives, 2’,3’,5’–tri–O–acetyl–6–thioguanosine (ta6TGuo), 2’,3’,5’–tri–O–acetyl–8–thioguanosine (ta8TGuo), and 2’,3’,5’–tri–O–acetyl–6,8–dithioguanosine (taDTGuo) were explored photophysically and photochemically. The nanosecond transient absorption and time–resolved near–infrared emission measurements were carried out to investigate the characteristics of their excited triplet states in acetonitrile solution. The quantum yield of intersystem crossing (∅ISC), the intrinsic decay rate constant (k0), the quenching rate constant by 3O2 (kq) and the self–quenching rate constant (kSQ) of their triplet states were all determined. From precise analysis of the quantum yield of 1O2* generation (∅Δ) against the concentration of dissolved molecular oxygen, the fraction of the triplet states quenched by dissolved oxygen which gives rise to 1O2* formation (SΔ) was successfully obtained with high accuracy. The ∅Δ values at low oxygen concentrations reveal these thioguanosines, particularly taDTGuo, can still effectively generate 1O2* under low molecular oxygen concentration like carcinomatous microenvironments. These findings indicate that taDTGuo would perform well as a potential agent for photo–induced cancer therapies.

Item Type: Journal Item
Copyright Holders: 2018 The Royal Society of Chemistry and Owner Societies
ISSN: 1474-9092
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Life, Health and Chemical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Research Group: eSTEeM
Item ID: 56726
Depositing User: Yao Xu
Date Deposited: 25 Sep 2018 15:51
Last Modified: 19 Sep 2019 14:05
URI: http://oro.open.ac.uk/id/eprint/56726
Share this page:

Metrics

Altmetrics from Altmetric

Citations from Dimensions

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU