Aplicação de métodos sintéticos via catálise com sais de cobre(i) e nanotubos de carbono decorados com nanopartículas de rutênio para a síntese de novos compostos antitumorais.

Abstract

Quinones are substances that may exhibit several biological activities, for instance, against different tumor cell lines. Due to their pharmacological properties, substances containing the quinoid moiety come to light the interest of the scientific community. The present work describes two strategies for obtaining new derivatives of this class of compounds: the union of two quinoid moieties through a triazole and oxidation of sulfides, present in quinones, to sulfones via nanocatalysis. Therefore, in the first part of this thesis, we describe eighteen new quinone derivatives obtained from a 1,3-dipolar cycloaddition reaction, catalyzed by Cu(I). These compounds possess two redox centers consisting of an ortho-quinone and a para-quinone, connected by a 1,2,3-triazole ring. The compounds were submitted to biological assays against different tumor and healthy cell lines. Several of them exhibited IC50 values below 0.5 µM in tumor cell lines, lower cytotoxicity in the normal cell line, with a good selectivity index. In the second section, a new methodology for oxidation of sulfide, present at quinone, to obtain sulfones is described. In this oxidation, ruthenium nanoparticles supported on carbon nanotubes were used as catalyst associated with a combination with sodium periodate (NaIO4), under mild conditions. Twenty sulfides, containing different substituents, were submitted to the developed reaction and the products were obtained in moderate to excellent yields.Among the twenty sulfones synthesized, twelve are new and three of them had their structure solved by X-ray crystallographic studies. The method developed also includes the recycling analysis of the catalyst, indicating that its performance remained similar after the fifth cycle of use. In conclusion, two strategies used in this work for the structural modification of quinones showed to be promising for obtaining compounds with potential biological application.