Sinteza zaviralcev MurA s tetrazolnim skeletom

Pirman, Anja (avtor), Frlan, Rok (mentor)

Razširjen pojav odpornosti bakterij na antibiotike je eden največjih izzivov in nakazuje potrebo po razvoju protibakterijskih zdravil z novimi mehanizmi delovanja. Odpornost na antibiotike vpliva na človeštvo po vsem svetu, povečuje obolevnost in umrljivost ter s tem resno ogroža javno zdravje. Krizo odpornosti na antibiotike lahko pripišemo prilagoditvi mikroorganizmov, prekomerni in napačni uporabi zdravil ter tudi pomanjkanju razvoja novih zdravil. Biosinteza peptidoglikana bakterijske celične stene je kompleksen proces, ki vključuje številne korake. Vse stopnje predstavljajo potencialne tarče za odkrivanje novih protibakterijskih učinkovin, saj je nepoškodovan peptidoglikan ključen za preživetje bakterij in specifičen za prokariontske celice. Odkritih je bilo že več učinkovin z delovanjem na pozne faze biosinteze peptidoglikana, v zadnjem času pa si prizadevajo razviti klinično uporabne zaviralce encimov Mur. Širokospektralni antibiotik fosfomicin je še vedno edini klinično uporaben zaviralec MurA, vendar si strokovnjaki prizadevajo, da bi našli nove učinkovine, ki bi ga nadomestile. Na katedri za farmacevtsko kemijo so po predhodnem encimskem testiranju komercialno dostopnih spojin na encimu MurA dobili nekaj zadetkov. Opravljena HPLC analiza je pokazala 90-95 % čistost nekaterih spojin, vendar po čiščenju s kromatografskimi metodami spojine niso bile več aktivne. To nas je usmerilo v raziskovanje vzroka lažno pozitivnih rezultatov. Postavili smo hipotezo, da so v prvotno testiranih vzorcih morda prisotne majhne količine nečistot, ki so strukturno podobne analiziranim spojinam. V okviru magistrske naloge smo zato sintetizirali serijo spojin, ki so strukturni analogi prvotnih zadetkov in bi lahko bile odgovorne za delovanje na encim MurA. Po biokemijskem testiranju se je izkazalo, da tudi te spojine ne delujejo na encim v pričakovanih koncentracijah oziroma so bile zelo šibko aktivne. Prišli smo do zaključka, da za prvotno aktivnost niso odgovorne sintetizirane spojine, temveč druge nečistote. Identificirali pa smo spojino, ki bi jo lahko uporabili za nadaljnji razvoj, če bi s kemijskim preoblikovanjem spojine uspeli izboljšati njeno aktivnost.

• Jezik: Slovenski jezik
• Ključne besede: bakterijska odpornost, protibakterijske učinkovine, zaviralci MurA, interferenčne spojine
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2023
• PID: 20.500.12556/RUL-152949
• Datum objave v RUL: 13.12.2023

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Synthesis of tetrazole-based MurA inhibitors

Izvleček

The widespread emergence of bacterial resistance to antibiotics is one of the greatest challenges and means that antibacterial drugs with new mechanisms of action must be developed. Antibiotic resistance is affecting humanity worldwide, increasing morbidity and mortality and thus seriously threatening public health. The antibiotic resistance crisis can be attributed to the adaptation of microorganisms, the overuse and misuse of drugs, and also the lack of development of new drugs. The biosynthesis of the peptidoglycan of the bacterial cell wall is a complex process involving many steps. All steps represent potential targets for the discovery of new antibacterial agents, as intact peptidoglycan is crucial for bacterial survival and specific to prokaryotic cells. Several agents have been discovered that target the late stages of peptidoglycan biosynthesis, and recent efforts have been made to develop clinically useful Mur enzyme inhibitors. The broad-spectrum antibiotic fosfomycin is still the only clinically useful MurA inhibitor, but experts are working to find new agents that could replace it. In the Department of Pharmaceutical Chemistry, some hits on the MurA enzyme were obtained after preliminary enzyme assays of commercially available compounds. The HPLC analysis performed showed purity of 90-95% for some compounds, but after purification by chromatographic methods, the compounds were no longer active. This prompted us to investigate the cause of false positive results. We hypothesized that small amounts of impurities structurally similar to the analyzed compounds might be present in the originally tested samples. Therefore, as part of the master's thesis, we synthesized a series of compounds that are structural analogs of the original hits and could be responsible for the action on the MurA enzyme. After biochemical tests, it turned out that even these compounds did not act on the enzyme at the expected concentrations, or only very weakly active. We concluded that it is not the synthesized compounds that are responsible for the initial activity, but other impurities. However, we have identified a compound that could be used for further development, if we manage to improve its activity through chemical transformation of the compound.

• Ključne besede: bacterial resistance, antibacterial agents, MurA inhibitors, interference compounds