Oncocalyxone A: electrochemical, spectroscopic investigation and studies of its interaction with DNA, nucleobases and N-acetylcysteine

• Autor(a) principal: Costa,Cicero de O.
• Data de Publicação: 2012
• Outros Autores: Costa,Erivaldo de O., Ferreira,Fabrícia da R., Viana,Luciana da S., Silva,Leonardo V. da, Silva,Francisco de A. dos Santos, Abreu,Fabiane C. de, Figueiredo,Isis M., Pinho Jr.,Waldomiro, Bento,Edson de S., Lemos,Telma L. G., Pessoa,Otília D. L., Aguilera-Venegas,Benjamin, Norambuena,Ester, Olea-Azar,Claudio, Goulart,Marília O. F.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532012000600024
• topic: oncocalyxone A; spectroelectrochemical-electron spin resonance; DNA interaction; N-acetylcysteine; Michael acceptor

The formation of paramagnetic species from oncocalyxone A in aprotic medium was confirmed by performing in situ electrochemical-electron spin resonance (E-ESR) experiments. The high delocalization of the radical generated at the first reduction potential is clearly evidenced by the hyperfine coupling of H-9 with the larger coupling constant, besides the couplings at the H-3 (close to quinone) and H-7 (far from the quinone nucleus) positions. In protic medium, together with pH dependence experiments, oncocalyxone A showed to be DNA-reactive through experiments with DNA sensors. Its reaction with N-acetylcysteine, with structural characterization of the addition products, proved its ability as Michael acceptor. Both aspects are important in terms of biological/pharmacological activities and indicate the present models as important tools in the screening of biologically active compounds.