title: Photophysical Properties of S, Se and Te-Substituted Deoxyguanosines: Insight into Their Ability To Act as Chemotherapeutic Agents.
abstract: Guanine and guanosine derivatives have long been in use as anticancer drugs and recently have been proposed also as photosensitizers in photodynamic therapy. By means of density functional theory and its time-dependent formulation, the potential power as UVA chemotherapeutic agents has been investigated computing the photophysical properties (absorption spectra, excitation energies, and spin-orbit matrix elements) of sulfur, selenium, and tellurium-substituted deoxyguanosines. Different pathways for the population of the lowest triplet state have been considered. Results show that all the examined systems have the lowest triplet state lying above the energy required for the production of the highly cytotoxic excited molecular oxygen1Δgand that the heavy atom effect ensures an efficient intersystem spin crossing.
authors.affiliation: Dipartimento di Chimica e Tecnologie Chimiche, University of Calabria , Via P. Bucci, 87036 Rende, Italy.
authors.forename: Jenny
authors.initials: J
authors.lastname: Pirillo
authors.affiliation: Dipartimento di Chimica e Tecnologie Chimiche, University of Calabria , Via P. Bucci, 87036 Rende, Italy.
authors.forename: Gloria
authors.identifier: 0000-0002-4686-6876
authors.initials: G
authors.lastname: Mazzone
authors.affiliation: Dipartimento di Chimica e Tecnologie Chimiche, University of Calabria , Via P. Bucci, 87036 Rende, Italy.
authors.forename: Nino
authors.initials: N
authors.lastname: Russo
authors.affiliation: Department of Biotechnologies and Biosciences, University of Milano-Bicocca , Piazza della Scienza 2, I-20126 Milano, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bertini
mesh_terms: D003849:Deoxyguanosine / Q000737:chemistry* / Q000494:pharmacology; D008027:Light; D008958:Models, Molecular; D008968:Molecular Conformation; D010778:Photochemotherapy; D011789:Quantum Theory; D012643:Selenium / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*
chemical_list: D013455:Sulfur; D003849:Deoxyguanosine; D012643:Selenium; D013691:Tellurium