Design,Synthesis And Bioactivity Of N-(1-(6-(substituted Phenyl)-pyridazine-3-yl)-piperidine-3-yl)-amide Derivatives Targeting JMJD6

The jumonji domain-containing protein 6(JMJD6)was a member of the large family of JmjC domain-containing proteins.JMJD6 was a histone arginine demethylase which catalyzed the demethylation reactions of histone H3 at arginine 2(H3R2)and histone H4 at arginine 3(H4R3).By the molecular docking technology and computeraided drug design,several series of compounds targeting JMJD6 were designed and synthesized.Through the screening of biological activities,we selected the most potential compounds,and studied the biological effects of these compounds,such as the anti-tumor proliferation activity and the binding ability of JMJD6.Based on JMJD6 inhibitor SKLB325,23 of N-(1-(6-(2-methoxyphenyl)pyridazine-3-yl)-piperidine-3-yl)-amide derivatives and 20 of 1-(6-(2-methoxyphenyl)pyridazine-3-yl)-N-substituted piperidine-3-formamide derivatives as novel JMJD6 inhibitors were designed and synthesized by scaffold hopping.We found that the activity of series B was poor,and the IC50 values were higher than 40 μM.The activity of series A is better than that of B series compounds.We screened compound A3(IC50=14.81±0.08 μM)and A13(IC50=10.07±0.57 μM)with better activity from a series compounds。.Compounds A3 and A13 inhibited the enzyme activity of JMJD6 and upregulated the protein and mRNA levels of p53,P21 and PUMA in a concentration and time-dependent manner.Based on the series A,35 of N-(1-(6-(substituted phenyl)-pyridazine-3-yl)piperidine-3-yl)-amide derivatives as novel JMJD6 inhibitors were designed and synthesized,and the strongest activity compounds,C31(IC50=1.53±0.08μM)and C34(IC50=2.86±0.28 μM)were obtained.Experimental results showed that compound C31 could bind to JMJD6 and inhibited the enzyme activity of JMJD6.In addition,C31 can upregulate the protein and mRNA levels of p53,p21 and PUMA in a concentration and time-dependent manner.Mouse breast cancer xenograft model showed that the compound C31 has anti-tumor effect in vivo and no obvious toxic effects on mice.We designed and synthesized 43 new dual target inhibitors of JMJD6 and HD AC as targets,and obtained the strongest activity compounds H15(IC50=1.70±0.12 μM),H35(IC50=0.44±0.02 μM)and H43(IC50=1.16±0.19 μM).We found that only compound H43 was a dual target inhibitor of JMJD6 and HDAC,H15 and H35 were only HD AC inhibitors.Finally,based on the ligand of E3 ubiquitin ligase CRBN thalidomide and compound C31,we designed and synthesized two novel PROTAC molecules targeting JMJD6.The results showed that compound D1 could change the protein and mRNA levels of p53,p21 and PUMA.However,compound D1 has no degradation effect of JMJD6.Therefore,we need further research to obtain novel PROTAC molecules with degradation effect of JMJD6.