Medicinal Electrochemistry of Halogenated and Nitrated Pterocarpanquinones

Autor(es)

Silva, Thaissa L. ^{[1, 2]} ; da Silva, Julio C. S. ^[1] ; Lima, Dimas J. P. ^[1] ; Ferreira, Fabricia R. ^[1] ; de Vasconcelos, Camila C. ^{[1, 3]} ; Santos, Danyelle C. ^[2] ; Netto, Chaquip D. ^{[4, 5]} ; Costa, Paulo R. R. ^[4] ; Goulart, Marilia O. F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Alagoas, Inst Quim & Biotecnol, BR-57072970 Maceio, AL - Brazil

^[2] Univ Fed Alagoas, Nucleo Ciencias Exatas NCEx, Campus Arapiraca, BR-57309005 Arapiraca, AL - Brazil

^[3] Ctr Univ CESMAC, BR-57081350 Maceio, AL - Brazil

^[4] Univ Fed Rio de Janeiro, Ctr Ciencias Saude, Nucleo Pesquisas Prod Nat, Lab Quim Bioorgan, Bloco H, BR-21941590 Rio De Janeiro, RJ - Brazil

^[5] Univ Fed Rio de Janeiro, Lab Quim, Campus Prof Aloisio Teixeira, BR-27930560 Macae, RJ - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 30, n. 11, SI, p. 2438-2451, NOV 2019.
• Citações Web of Science: 0

Resumo

Electrochemical methods are considered useful tools for simulations of biological redox reactions. The activities of quinones depend on their bioreduction. Biologically active pterocarpanquinones LQB-149 (nitroderivative), 150 and 151 (bromo and chloroderivatives, respectively) were electrochemically investigated by cyclic voltammetry, differential pulse voltammetry, and in situ UV-Vis spectroelectrochemistry, in aprotic media (N, N-dimethylformamide (DMF) + tetra-N-butylammonium (TBAPF 6)). The data obtained regarding their reduction mechanisms, positive reactivity with oxygen and analysis of the electrogenerated intermediates were useful in explaining their biological outcomes. The appearance of bands at 397 and 480 nm, for the halogenated compounds, suggests the generation of transient quinonemethides (QM), electrophilic intermediates related to their activity. As an additional proof for the intermediacy of QM, in the redox processes, chemical reduction of LQB-150, in the presence of hexanethiol was performed and led to a thioalkylated quinone. For the nitroderivative, a broad band appeared at 432 nm, corresponding to the generation of the nitroradical anion, giving rise to a dianion diradical, after reduction at the second wave potential. Computational data correlate well with electrochemical experiments. Homogeneous electron transfer to oxygen, yielding reactive oxygen species, the generation of electrophilic species and the radical reactivity, explain partially the mechanism of biological action. (AU)

• Processo FAPESP: 14/50867-3 - INCT 2014: Instituto Nacional de Ciência e Tecnologia de Bioanalítica
• Beneficiário: Marco Aurelio Zezzi Arruda
• Modalidade de apoio: Auxílio à Pesquisa - Temático