Design,Synthesis And Biological Evaluation Of 2-methyl-(1,1'-biphenyl)-pyrimidine Conjugates

Cancer has always been a hot topic that people have paid attention to.Its high morbidity and high mortality are a serious threat to human health and have brought huge economic losses worldwide.Traditional anti-tumor treatment methods have a limited role in inhibiting tumor progression,thus,the development of new drugs is of particularly importance.Antibody drugs designed for targeting the programmed death receptor 1?PD-1,also known as CD279?signaling pathway have shown significant antitumor effects on clinic.However,small molecule inhibitors targeting PD-1/PD-L1 have not yet been successfully developed into marketed drugs.The main reason is that the target for PD-1/PD-L1 is composed of large and flat protein interactions,and the binding site is large and hydrophobic,small molecule inhibitors that can prevent the effects of PD-1and PD-L1 to achieve tumor immunotherapy have not been discovered for a long time;Secondly,the related small molecule inhibitor research started late,and the research was basically started after the antibody drugs were marketed.However,some good small molecule skeleton structure has been reported,the skeleton formed by the oxyether bond connecting biphenyl and aromatic heterocycle is one of the better parent structures,and many reported small molecules that are active against PD-1/PD-L1 contain this structure.On the other hand,pyrimidine-containng compounds have attracted much attention in the fields of medicine and pesticides because of their wide biological activity.In recent years,more and more pyrimidine-containng compounds have been reported to have good antitumor activity,and many drugs that have been marketed also have the structure of 2-aminopyrimidine.Therefore,in this thesis,by coupling2-aminopyrimidine and biphenyl as the core skeleton,27 novel 2-?2-methyl-3-phenylbenzylamino?-pyrimidines conjugates with the 4,6 position of the pyrimidine ring having different side chain groups are designed and synthesized.Then,we investigated anti-tumor activity and preliminary ability of compounds to inhibit PD-1/PD-L1 interaction.Results showed that 2-methyl-?1,1-biphenyl?-pyrimidine conjugates represented a killing effect on tumor cells through CCK-8cytotoxicity screening test,wound healing,transwell and flow cytometry?FCM?,especially for A549 cells,Hep G2 cells,HT-29 cells and SK-OV-3 cells.Amongst all compounds,the compounds with better cytotoxic effect are 15a,15d,16b,in particular,16b poosessed the strongest anti-HT-29 cell ability with an IC₅₀ value of 2.08??.At the same time,in order to explore whether the activity of anti-tumor with the compounds was achieved by blocking the interaction of PD-1/PD-L1,consequently restoring the activity of T cells,blocking assay of PD-1/PD-L1 was conducted through homogeneous time-resolved fluorescence technology?HTRF?.Comprehensive experimental results show that the compound achieves anti-tumor effects through non-immune pathways,less likely through immune pathway.This study implys that in order to develop 2-methyl-?1,1-biphenyl?-pyrimidine conjugates to antitumor active molecules targeting PD-1/PD-L1,but the HTRF test results are not ideal,so the molecular structure needs to be further optimized.