Pirillo Jenny, Mazzone Gloria, Russo Nino, Bertini Luca
Dipartimento di Chimica e Tecnologie Chimiche, University of Calabria , Via P. Bucci, 87036 Rende, Italy.
Department of Biotechnologies and Biosciences, University of Milano-Bicocca , Piazza della Scienza 2, I-20126 Milano, Italy.
J Chem Inf Model. 2017 Feb 27;57(2):234-242. doi: 10.1021/acs.jcim.6b00486. Epub 2017 Jan 12.
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 oxygen Δ and that the heavy atom effect ensures an efficient intersystem spin crossing.
鸟嘌呤和鸟苷衍生物长期以来一直被用作抗癌药物，最近也被提议用作光动力疗法中的光敏剂。通过密度泛函理论及其含时公式，研究了硫、硒和碲取代的脱氧鸟苷作为UVA化疗药物的潜在能力，计算了它们的光物理性质（吸收光谱、激发能和自旋轨道矩阵元）。考虑了最低三重态的不同布居途径。结果表明，所有研究的体系最低三重态的能量高于产生高细胞毒性的激发态分子氧Δ所需的能量，并且重原子效应确保了有效的系间自旋交叉。
