Sinteza agonistov Toll-u podobnih receptorjev 7 in 8 z izoksazolo[5,4-d]pirimidin-4(5H)-onskim in kinazolin-4(3H)-onskim osnovnim skeletom

Petrič, Neja (author), Sova, Matej (mentor)

Glavna naloga imunskega sistema je varovanje organizma pred vdorom tujkov v telo. Sestavljen je iz treh linij obrambe z naraščujočo stopnjo specifičnosti proti patogenom. Del prirojenega imunskega sistema so receptorji za prepoznavanje molekulskih vzorcev – PRR, ki specifično prepoznavajo s patogeni ali s poškodbo povezane molekulske vzorce (PAMP in DAMP). Ena izmed skupin PRR so tudi Toll-u podobni receptorji (TLR).V magistrski nalogi smo se osredotočili na strukturno podobna znotrajcelična endosomska receptorja TLR7 in TLR8, katerih aktivacija povzroči povečano izražanje vnetnih citokinov in interferonov tipa I ter s tem povezano imunsko aktivacijo, protivirusno in protitumorsko delovanje. Prav zaradi tega se agonisti TLR7 in TLR8 raziskujejo kot potencialne učinkovine za zdravljenje različnih bolezenskih stanj, kot so rak, virusne okužbe in astma. V okviru magistrske naloge smo na osnovi spojine zadetka 3-(1-hidroksiheksan-2-il)-5-metilkinazolin-4(3H)-ona načrtovali in sintetizirali različne strukturne analoge z izoksazolo[5,4-d]pirimidin-4(5H)-onskim in kinazolin-4(3H)-onskim osnovnim skeletom kot potencialne dualne agoniste TLR7 in TLR8. Za sintezo obeh serij spojin smo uporabili šeststopenjska sintezna postopka. V obeh primerih smo najprej sintetizirali osnovni skelet, temu pa sta sledila N-alkiliranje z različnimi 2-bromo estri in redukcija estra do alkohola. V primeru nizkih izkoristkov smo sintezne postopke optimizirali s spremembo topil in reakcijskih pogojev. Končne spojine in nekatere intermediate smo biološko testirali na celičnih linijah HEK293 hTLR7. Spojine, ki so izkazovale preliminarno agonistično aktivnost na TLR7, smo testirali še na celičnih linijah HEK293 hTLR8, ter jim določili EC50 vrednosti za TLR7 in TLR8. Spojine z izoksazolo[5,4-d]pirimidin-4(5H)-onskim osnovnim skeletom niso izkazovale agonističnega delovanja na TLR7, medtem ko so bili kinazolin-4(3H)-onski derivati agonisti tako TLR7 kot tudi TLR8. Kot najmočnejši agonist TLR7 se je izkazala spojina 31 (EC50 = 1,70 µM), kot najmočnejši agonist TLR8 pa spojina 30 (EC50 = 13,2 µM). Rezultati bioloških testiranj so pokazali, da so spojine 29, 30 in 31 dualni agonisti TLR7/8 z delovanjem v nizkih mikromolarnih koncentracijah, zato predstavljajo dobro izhodišče za nadaljnje raziskave in optimizacije.

• Language: Slovenian
• Keywords: imunski sistem, Toll-u podobni receptorji, TLR7, TLR8, agonist
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2024
• PID: 20.500.12556/RUL-164861
• Publication date in RUL: 14.11.2024

Secondary language

• Language: English
• Title: Synthesis of Toll-like receptors 7 and 8 agonists with isoxazolo[5,4-d]pyrimidin-4(5H)-one and quinazolin-4(3H)-one scaffold

Abstract

The immune system's main task is to protect the body from foreign objects. It consists of three lines of defense with increasing specificity against pathogens. Part of the innate immune system are the pattern recognition receptors (PRRs), which specifically recognize pathogen- or damage-associated molecular patterns (PAMPs and DAMPs). Toll-like receptors (TLRs) also belong to one of the PRR classes. In the master's thesis, we focused on the structurally similar intracellular endosomal receptors TLR7 and TLR8, whose activation causes the increased expression of inflammatory cytokines and type I interferons and the associated immune response, antiviral and antitumor activity. Therefore, TLR7 and TLR8 agonists are being investigated as potential drugs for the treatment of various diseases such as cancer, viral infections and asthma. In the master's thesis, we designed and synthesized various structural analogs with isoxazolo[5,4-d]pyrimidin-4(5H)-one and quinazolin-4(3H)-one scaffold as potential dual agonists of TLR7 and TLR8 receptors. A six-step synthetic procedure was used for the synthesis of both series of compounds. In both cases, the main scaffold was synthesized first, followed by N-alkylation with various 2-bromo esters and reduction of the ester to alcohol. In case of low yields, synthetic procedures were optimized by changing the solvents and reaction conditions. The synthesized compounds and some intermediates were tested biologically on HEK293 hTLR7 cell lines. Compounds that showed preliminary agonistic activity on TLR7 were also tested on HEK293 hTLR8 cell lines, and their EC50 values for TLR7 and TLR8 were determined. Compounds with isoxazolo[5,4-d]pyrimidin-4(5H)-one scaffold did not show any agonistic activity on neither TLR7 nor TLR8, while quinazolin-4(3H)-one derivatives were found to be agonists on both receptors. The most potent TLR7 agonist was compound 31 (EC50 = 1,70 µM), while the most potent TLR8 agonist was compound 30 (EC50 = 13,2 µM). The results of the biological tests showed that compounds 29, 30 and 31 are dual TLR7/8 agonists in low micromolar concentrations, and thus represent a good starting point for further research and optimization.

• Keywords: immune system, Toll-like receptors, TLR7, TLR8, agonist