Design and synthesis of maleimide inhibitors of murA ligase

Pojav in širjenje bakterijskih sevov, odpornih na protibakterijske učinkovine, predstavlja velik zdravstveni problem na svetovni ravni, zato je vedno večja potreba po odkrivanju novih zdravil. Med najbolj znane tarče pri iskanju novih protibakterijskih učinkovin sodijo encimi, ki sodelujejo v biosintezi peptidoglikana, ključnega gradnika bakterijske celične stene. Prvi korak te biosinteze katalizira encim MurA (UDP-N-acetilglukozamin enolpiruvil transferaza), ki ga najdemo v številnih bakterijskih vrstah. V sesalskih celicah ni prisoten, zato predstavlja ugodno tarčo za razvoj selektivnih protibakterijskih učinkovin. Edini zaviralec encima MurA v klinični rabi je fosfomicin, ki se uporablja za zdravljenje okužb urinarnega trakta in okužb z večkrat odpornimi mikroorganizmi. Tudi pri fosfomicinu se danes soočamo s problemom bakterijske odpornosti, zato je nujno potreben razvoj novih inhibitorjev z drugačno strukturo ali drugačnim mehanizmom delovanja. V sklopu magistrske naloge smo načrtovali in sintetizirali maleimidne derivate, potencialne zaviralce encima MurA. Maleimid smo izbrali na osnovi rezultatov predhodnega testiranja knjižnice fragmentov. Nanj smo pripenjali razne alifatske in aromatske fragmente ter ugotavljali, kateri strukturni deli molekule tvorijo boljše interakcije z vezavnim mestom encima MurA. Sintetizirali smo 15 končnih spojin in njihovih intermediatov, ki smo jih fizikalno-kemijsko in spektroskopsko ovrednotili ter jim določili aktivnost z biološkim testiranjem in vitro na izoliranem encimu MurA. Večina spojin je izkazovala dobre zaviralne lastnosti, zato so primerne za nadaljnjo optimizacijo in raziskovanje novih zaviralcev encima MurA.The occurrence and spread of bacterial strains that are resistant to antibacterial agents represent a major global health problem. Because of that, there has been an increased need to discover new drugs. Enzymes involved in peptidoglycan biosynthesis, a key building block of the bacterial cell wall, are among the most well-known antibacterial targets. The first step of this biosynthesis is catalyzed by the MurA enzyme (UDP-N-acetylglucosamine enolpyruvyl transferase), which can be found in many bacterial species. This enzyme is not present in mammalian cells and therefore represents a favorable target for the development of selective antibacterial agents. The only MurA enzyme inhibitor in clinical use to date is fosfomycin, which is used to treat urinary tract infections and infections with multidrug-resistant microorganisms. Recently, however, fosfomycin has been reported to have problems with bacterial resistance, and therefore, the development of new inhibitors with a different structure or different mechanism of action is necessary. As a part of the master’s thesis, we designed and synthesized maleimide derivatives, potential inhibitors of the MurA. Maleimide was chosen based on the results of a preliminary fragment library testing. We attached various aliphatic and aromatic fragments to it and determined which structural parts of the molecule form better interactions with the binding site of the MurA enzyme. We synthesized 15 final compounds and their intermediates, which were physiochemically and spectroscopically evaluated. Moreover, their activity was determined by in vitro biological testing on the isolated MurA enzyme. Most of the compounds showed good inhibitory properties and are thus suitable for further development as of new MurA inhibitors