TITLE:
Theoretical Studies of Photodynamic Therapy Properties of Azopyridine δ-OsCl2(Azpy)2 Complex as a Photosensitizer by a TDDFT Method
AUTHORS:
Wawohinlin Patrice Ouattara, Kafoumba Bamba, Affi Sopi Thomas, Fatogoma Diarrassouba, Lamoussa Ouattara, Massapihanhoro Pierre Ouattara, Kouakou Nobel N'guessan, Mamadou Guy Richard Kone, Charles Guillaume Kodjo, Nahossé Ziao
KEYWORDS:
Time Dependent-Density Functional Theory, Azopyridine, Excited States, Photosensitization, Photodynamic Therapy, Osmium
JOURNAL NAME:
Computational Chemistry,
Vol.9 No.1,
January
22,
2021
ABSTRACT: Photochemical reactions have an important place in photodynamic treatments. A good use of this therapeutic method requires a good mastery of the mechanisms of the reactions involved. Therefore, we have explored in this work the photosensitization mechanism of an organometallic complex of azopyridine δ-OsCl2(Azpy)2 through a calculation with the method of Time Dependent Density Functional Theory TDDFT. First, we evaluated the effect of polar and non-polar solvents on the triplet and singlet excited states of this complex. Then secondly, we highlighted the photosensitization mechanism to understand how the complex acts over the diseased cells. These investigations have shown that the δ-OsCl2(Azpy)2 complex is likely to develop photodynamic activity according to two mechanisms: on one hand, it can generate damage to DNA bases or target tissues indirectly through the production of singlet oxygen in water and in DMSO. On the second hand, through the production of the anionic superoxide radical in water can act directly or indirectly on these substrates. In addition, polar solvents are assumed to better carry out the photochemical reactions of this azopyridine complex of osmium.