X-ray induced luminescence spectroscopy for DNA damaging intermediates aided by

Purpose: To identify the bonding sites of initial radiation interaction with DNA and to trace the following chemical reaction sequences on the pathway of damage induction, we carry out a spectroscopy XIL (X-ray induced luminescence)
using soft X-ray synchrotron radiation. This is a non-destructive analysis of the excited intermediate species produced in a molecular mechanism on the damage induction pathway.
Materials and Methods: We introduce aqueous samples of UMP (uridine-5’-monophosphate) in the vacuum by the use of a liquid micro-jet technique. The luminescence in the region of UV-VIS (from visible to ultraviolet) radiation induced after the absorption of monochromatic soft X-ray by aqueous UMP is measured with sweeping the soft X-ray energy in the region of 370 eV – 560 eV.
Results: The enhanced XIL intensities for aqueous UMP in the region of soft X-ray of 410 eV – 530 eV (in “water window” region) are obtained (Kojima et al, 2019). The enhancement of XIL intensities in the UV-VIS region, relative to the water control, is explained by the excitation and ionization of a K-shell electron of nitrogen atoms in the uracil moiety. The enhanced XIL intensities do not match the structure of XANES (X-ray absorption near-edge structure) of the aqueous UMP. This suggests that the XIL intensities reflect the quantum yields of
luminescence, or the quantum yields conversion by UMP of an absorbed X-ray into UV-VIS radiation. In this paper, spectra of luminescence are shown to be resolved by combining low pass filters. The filtered luminescence spectra are obtained at the center of gravity (λc) of the band pass wavelength regions at λc =270nm, 295 nm, 340nm, 385 nm, 450 nm, and 525 nm., which show a trend similar to the fluorescence of nucleobases induced by ultraviolet radiation.
Conclusion: It is concluded that the origin of the observed XIL is the hydrated uracil moiety in aqueous UMP, decomposition of which is suppressed by the migration of excess charge and internal energy after the double ionization due to
Auger decay.

書誌情報

International Journal of Radiation Biology

発行日 2021-08

出版者

Taylor & Francis

ISSN

収録物識別子タイプ

ISSN

収録物識別子

0955-3002

DOI

識別子タイプ

DOI

Versions

Ver.1

2023-05-15 17:05:16.463423

Show All versions

Cite as

エクスポート

OAI-PMH

JPCOAR 2.0
JPCOAR 1.0
DublinCore
DDI

Other Formats

JSON
BIBTEX

インデックスリンク

インデックスツリー

アイテム