Menezes, Fabricio GavaSantos, Alane Priscilla Américo dos2021-10-042021-10-042021-05-10SANTOS, Alane Priscilla Américo dos. Estudos computacionais da reação de L-cisteína, Homocisteína e Glutationa com o quimiodosímetro 2,3-dicloro-6,7-dinitroquinoxalina. 2021. 45f. Dissertação (Mestrado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2021.https://repositorio.ufrn.br/handle/123456789/41556Biothiols, such as L-cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), are species involved in several biological processes such as protein and enzyme formation; action in the detoxification of xenobiotics and cellular redox homeostasis; having its dysfunctions associated with cardiovascular problems, neurodegenerative, osteoporosis, among others. Therefore, the development of methodologies aimed at the selective detection of these species is an important field of research. The present work consists of providing theoretical support for the results obtained from the investigation of the compound 2,3-dichloro-6,7- dinitroquinoxaline (DCDNQX) as a candidate for selective chemodosimeter for the amino acid L-cysteine, being extended also to the reactions of that substrate with Hcy and GSH. The DFT M06-2X method was used with the base function 6- 311+G (2d, p). Possible mechanistic routes for a series of reactions were considered, considering the versatility of Cys, Hcy and GSH as nucleophiles and considering the different possibilities of nucleophilic attacks by amino and/or thiol groups, both for mono- and di-substitutions, including processes of intramolecular cyclization. The geometric parameters of all chemical species proposed were optimized in search of thermodynamic parameters, in addition to calculating the transition states for the formation of possible products. The results indicate that sulfur attack is preferable to nitrogen attack, and the products resulting from this attack are more stable. The effect of the structure on possible intramolecular cyclization processes was studied too.Acesso AbertoQuímica orgânicaBiotióis2,3-dicloro-6,7-dinitroquinoxalinaQuimiodosímetroM062XmasterThesis