The Excited State Dynamics of a Mutagenic Guanosine Etheno Adduct Investigated by Femtosecond Fluorescence Spectroscopy and Quantum Mechanical Calculations.

Autor: Lizondo-Aranda P; Instituto Universitario Mixto de Tecnología Química (UPV-CSIC), Universitat Politècnica de Valencia, Consejo Superior de Investigaciones Científicas, Avda de los Naranjos s/n, Valencia, 46022, Spain., Gustavsson T; Université Paris-Saclay, CEA, LIDYL, 91191, Gif-sur-Yvette, France., Martínez-Fernández L; Departamento de Química Física de Materiales, Instituto de Química Física Blas Cabrera, IQF-CSIC, Calle Serrano 119, 28006, Madrid, Spain., Improta R; Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via De Amicis 95, I-80145, Napoli, Italy., Lhiaubet-Vallet V; Instituto Universitario Mixto de Tecnología Química (UPV-CSIC), Universitat Politècnica de Valencia, Consejo Superior de Investigaciones Científicas, Avda de los Naranjos s/n, Valencia, 46022, Spain.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2024 Sep 02; Vol. 30 (49), pp. e202401835. Date of Electronic Publication: 2024 Jul 31.
DOI: 10.1002/chem.202401835
Abstrakt: Femtosecond fluorescence upconversion experiments were combined with CASPT2 and time dependent DFT calculations to characterize the excited state dynamics of the mutagenic etheno adduct 1,N 2 -etheno-2'-deoxyguanosine (ϵdG). This endogenously formed lesion is attracting great interest because of its ubiquity in human tissues and its highly mutagenic properties. The ϵdG fluorescence is strongly modified with respect to that of the canonical nucleoside dG, notably by an about 6-fold increase in fluorescence lifetime and quantum yield at neutral pH. In addition, femtosecond fluorescence upconversion experiments reveal the presence of two emission bands with maxima at 335 nm for the shorter-lived and 425 nm for the longer-lived. Quantum mechanical calculations rationalize these findings and provide absorption and fluorescence spectral shapes similar to the experimental ones. Two different bright minima are located on the potential energy surface of the lowest energy singlet excited state. One planar minimum, slightly more stable, is associated with the emission at 335 nm, whereas the other one, with a bent etheno ring, is associated with the red-shifted emission.
(© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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