Sinteza N-fenilaziridinskih zaviralcev encima MurA

Nussdorfer, Klara (avtor), Frlan, Rok (mentor)

Odkritje antibiotikov je zelo pomemben znanstveni dosežek in začetek njihove uporabe je močno izboljšal klinične izide zdravljenja bakterijskih okužb. Z naraščanjem uporabe antibiotikov, opažamo povečan pojav bakterij, ki so nanje odporne. Odpornost bakterij na antibiotike predstavlja veliko grožnjo javnemu zdravju. Zaradi stalnega prilagajanja bakterij na nove načine zdravljenja, je potrebno pospešeno iskati nove učinkovite antibiotike. Zaviranje sinteze celične stene je dobra selektivna tarča antibiotikov, saj je prisotna le v bakterijskih celicah. Osnovni gradnik celične stene je premrežen polimer peptidoglikan, ki ohranja strukturo celice ter nasprotuje turgorskemu tlaku. V začetni stopnji sinteze peptidoglikana svojo nalogo opravlja encim MurA, ki katalizira prenos enolpiruvata iz fosfoenolpiruvata na UDP-N-acetilglukozamin, in mu pravimo tudi UDP-N-acetilglukozamin enolpiruvil transferaza. Kot zaviralec MurA encima je v klinični uporabi po dolgih letih še vedno le fosfomicin, ki s svojo strukturo posnema encimski substrat fosfoenolpiruvat. Zaradi razvoja odpornosti bakterij na fosfomicin, je treba iskati nove potencialne spojine, ki bodo zavirale to validirano tarčo. Pri eksperimentalnem delu smo sintetizirali nove zaviralce MurA encima z N-fenilaziridinsko strukturo, ki smo jih načrtovali s pomočjo posnemanja osnovne strukture fosfomicina. Razvili smo sintezno pot iz izhodne 3-aminobenzojske kisline do 3-azidobenzojske kisline, na katero smo v nadaljevanju pripenjali različne aminokisline preko amidne vezi. Nato smo azidno skupino pretvorili v aziridinski obroč z etil akrilatom in na koncu hidrolizirali še ester na omenjenem obroču. Sintetizirane spojine smo ovrednotili s spektroskopskimi in kromatografskimi metodami. Zaviralno aktivnost smo preverili z biološkim testiranjem na encimu MurA iz bakterije E. coli. Dve spojini sta izkazali zaviralno aktivnost in predstavljata dobro osnovo za nadaljnji razvoj optimiziranih zaviralcev MurA z aziridinsko strukturo.

• Jezik: Slovenski jezik
• Ključne besede: protibakterijske učinkovine, odpornost, peptidoglikan, zaviralci, encim, MurA, fosfomicin, aziridin
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2022
• PID: 20.500.12556/RUL-143533
• Datum objave v RUL: 24.12.2022

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Synthesis of N-phenylaziridine-based MurA enzyme inhibitors

Izvleček

The discovery of antibiotics was a very important scientific achievement, and their introduction to patients has greatly improved the clinical outcomes of treating bacterial infections. With the increasing use of antibiotics, we are seeing an increased occurrence of bacteria that are resistant to them. Bacterial resistance to antibiotics represents a major threat to public health. Bacterial evolution is constantly taking place and it is of vital importance to keep discovering and researching new substances. Inhibiting synthesis of cell wall is a very good selective target for antibiotic agents, because it is present only in bacterial cells. Building block of the cell wall is cross-linked polymer peptidoglycan, with the purpose of maintaining structural integrity of the cell and withstanding the forces of turgor pressure. In the initial stage of peptidoglycan synthesis MurA enzyme catalyses the reaction of transferring phosphoenolpyruvate to UDP-N-acetylglucosamine. That is why it is also called UDP-N-acetylglucosamine enol pyruvyl transferase. After many years, fosfomycin is still the only inhibitor of the MurA enzyme in clinical use. Fosfomycin mimics the MurA enzyme substrate phosphoenolpyruvate. Due to the inevitable development of resistance to a known MurA target, fosfomycin, it is necessary to discover new potential compounds. In our experimental work we synthetized N-phenylaziridine inhibitors of MurA enzyme which we designed by imitating the basic structure of fosfomycin. We developed a synthesis path from the starting 3-aminobenzoic acid to 3-azidobenzoic acid. Subsequently, various amino acids were attached with an amide bond, and then the azido group was converted into an aziridine ring with ethyl acrylate. Finally, we hydrolysed the ester on the aziridine ring. The synthesized compounds were evaluated by spectroscopic and chromatographic methods. The inhibitory activity was assessed with biological testing on the MurA enzyme from E. coli. Two compounds showed inhibitory activity, but their structure would need further optimization.

• Ključne besede: antibiotics, bacterial resistance, peptidoglycan, inhibitors, enzyme, MurA, fosfomycin, aziridine