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Interactions between temozolomide and guanine and its S and Se‐substituted analogues
Author(s) -
Kasende Okuma Emile,
Matondo Aristote,
Muya Jules Tshishimbi,
Scheiner Steve
Publication year - 2017
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.25294
Subject(s) - tautomer , guanine , chemistry , perpendicular , molecule , density functional theory , maxima and minima , potential energy surface , dispersion (optics) , computational chemistry , crystallography , molecular physics , stereochemistry , physics , geometry , quantum mechanics , mathematics , organic chemistry , nucleotide , mathematical analysis , biochemistry , gene
Temozolomide was paired with guanine, 6‐selenoguanine, and 6‐thioguanine, as well as the SH tautomer of the latter. The potential energy surface of each heterodimer was searched for all minima, using Dispersion‐Corrected Density Functional Theory and MP2 methods. Among the dozens of minima, three categories were observed. Stacked geometries place the aromatic systems of the two molecules parallel to one another, while the two systems are roughly perpendicular to one another in a second category. Also found are coplanar structures held together by H‐bonds. Dispersion proves to be a dominating attractive force for the stacked structures, less so for perpendicular, and smallest for the coplanar dimers. Geometries and energetics are relatively insensitive to S and Se substitution, but tautomerization reverses relative stabilities of different geometries.