Design, synthesis and pharmacological evaluation of new enzyme inhibitors

Abstract

My PhD research plan relates to the exploration of the structural requirements for the modulation of enzymes involved in the pathogenesis of viral infections and inflammatory disorders. The first part of my doctoral project focused on the study of viral targets, particularly the main protease (Mpro) of SARS-CoV-2, the etiologic agent of COVID-19 that caused not only the biggest health crisis in the last century but also an unrecoverable socio-economic collapse. Despite all the efforts, addressed to build an efficient vaccine campaign, the virus spread is still ongoing and the challenge is still open. So, in the first chapter of this PhD thesis I report a step-by-step in silico design of a library of peptidomimetic compounds able to inhibit Mpro: the synthesized derivatives were screened by enzymatic assays, conducted on different viral targets, and, then, cellular activity was evaluated using Vero cells based viral infection model, leading to the identification of a dual inhibitor (29) of the two proteases of SARS-CoV-2, the main protease (Mpro) and the papain-like protease (PLpro). Subsequently, in vitro studies of a second series of molecules, designed from the most potent derivative of the first series, led to the identification of a new hit compound (51) characterized by high inhibitory potency against Mpro, as well as remarkable antiviral activity against several variants of SARS-CoV-2. Metabolic pathways involving arachidonic acid (AA) play key roles in cardiovascular physiology, carcinogenesis, and in many inflammatory diseases such as asthma or arthritis, so the second chapter of this PhD thesis focuses on the study of two enzymatic targets involved in the metabolism of arachidonic acid: the 5-lipoxigenase and the soluble epoxide hydrolase (sEH). In vitro and in vivo characterization of a first series of indoline scaffold derivatives led to the identification of a dual inhibitor of the two enzymes (73), while additional assays conducted on successive series of compounds designed as selective inhibitors of the enzyme sEH, led to the identification of an indole derivative (110) as a selective inhibitor of epoxide hydrolase, paving the way for further investigation as well as optimization of a new series of analogues.[edited by Author]