Development of new Catechol-Omethyltransferase inhibitors

• Autor(a) principal: Vicente, Pedro Miguel da Cruz
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/11498
• topic: Catecol-O-Metiltransferase; Desordens Neurológicas; Inibidores da Comt; Triazolopirimidinas; Domínio/Área Científica::Engenharia e Tecnologia::Biotecnologia

The Catechol-O-methyltransferase (COMT, EC 2.2.1.6) is an enzyme responsible for the Omethylation of catechol substrates, such as catecholamines and catechol estrogens. Considering its physiological functions and the existence of polymorphisms, several studies associate COMT with the pathogenesis of several neurological disorders, especially with Parkinson’s Disease (PD) as well as with cardiovascular and hormone-dependent cancers, like breast cancers. Given the important role that COMT has in the catecholamines and catechol estrogens metabolism, COMT has become a relevant therapeutic target. Currently, the most effective and clinically approved by the Federal Drug Administration and the European Medicines Agency for the PD therapy consists of the use of Levodopa, combined with COMT inhibitors. Since the commercially available inhibitors for this enzyme still display a lot of disadvantages, like hepatoxicity, difficulty to reach the brain, among others, the main goal of this work was to develop new COMT inhibitors with potential clinical interest for the PD therapy. For this, triazolopyrimidinics were prepared through the Biginelli reaction, that can be considered catechol bioisosteres, therefore have a higher potential to interact with COMT. This hypothesis was confirmed through molecular docking, being predicted similar interactions as the ones that the catecholic substrates forms with the COMT active site. Their inhibitory properties were evaluated in human recombinant COMT lysates, after the compounds’ incubation at 10 and 100 µM. Contrary to what was expected, the compounds increased the enzyme specific activity, being considered COMT stabilizers. The compounds cytotoxicity was also evaluated in neural dopaminergic rat cells (N27), in the same concentrations. The vast majority of compounds at 10 µM did not exhibited cytotoxicity, being observed similar values to those of the commercial COMT inhibitors, Entacapone and Tolcapone, in the studied cell line. As expected, with the increase in compounds’ concentration (100 µM) a decrease in the relative cell proliferation was observed, reaching values considered to be cytotoxic. Altogether, the synthesized compounds at the concentration of 10 µM stabilized COMT and did not induce cytotoxicity in the N27 cells. In sum, these compounds may be useful for thermal stability assays, crystallography, structure-activity relationship studies and display potential to be studied in specific breast cancers cell lines.