Design,Synthesis And Antitumor Evaluation Of Novel 4-Phenoxypyridine Bearing Quinoxalidone As C-Met Kinase Inhibitors

c-Met,also referred to as hepatocyte growth factor receptor（HGFR）,is a member of receptor tyrosine kinase encoded by proto-oncogene Met.HGF/c-Met signaling can promote cell proliferation,differentiation and metabolism,whereas aberrant HGF/c-Met pathway activities contributes to cancer initiation and progression,notably,c-Met activity plays a key role in metastasis of tumor cells.Therefore,c-Met has become an important drug targets for the development of anticancer drugs.Based on the understanding of the cocrystal structural between c-Met and TypeⅡc-met kinase inhibitors,the 4-phenoxypyridine nucleus structure was retained.Using classical drug design principles,the structure with anti-tumor activity quinoxalidone was introduced into the linker parts;further more,the pyridyl,phenoxy,linker and terminal benzene ring parts were modified respectively.Finally,32 small molecular compounds with novel structure were designed and synthesized.The structure of the target compounds was confirmed by Mass Spectrometry（MS）,Infrared Spectroscopy（IR）,Nuclear Magnetic Resonance Hydrogen Spectroscopy（¹H NMR）,and structure of some compounds was further verified by Nuclear Magnetic Resonancemr Carbon Spectroscopy(¹³C NMR).Target Compounds were evaluated for the activity against c-Met kinase,inhibiting activities of ten compound on c-Met with the IC₅₀values lesses than 10 n M,especially the three compounds（Z-24,Z-25,Z-27）showed better activity against c-Met compared with the positive drug Foretinib,with the IC₅₀values of 2.31 n M,1.91 n M and 2.44 n M,respectively.Some of the target compounds displayed potent activity against three cancer cells lines（A549,H460 and HT29）,the most promising compound Z-25 exhibits excellent anticancer activity against A549,H460 and HT29cell lines with the IC₅₀values of 1.57 n M,0.94 n M and 0.65 n M,which were equal to the positive drug Foretinib,respectively.At the same time,according to the results of c-Met kinase experiments,the structure-activity relationship of the target compounds was preliminarily investigated.The mechanism of promising compound Z-25 was studied:AO-EB Fluorescence staining showed that the compound Z-25 could induce apoptosis of HT29 cells and A549 cells in aconcentration-dependent manner;Flow Cytometry showed that the apoptosis rate of HT29 cells increased with the increase of the concentration of compound Z-25 administration;the results of Scratch Formation experiments showed that the compound Z-25 could inhibit the migration ability of A549 cells significantly,and the cell mobility was negative correlated with administration concentration.The Docking Studies indicated that compound Z-25 was potently bound to the active binding site of c-Met,which conformed to the typeⅡc-Met kinase binding mode:More importantly,Z-25 can form hydrogen bonds with Met1160 in the c-Met hinge region;moreover,the quinoxalidone structure of the linker parts can also formed hydrogen bonds with Lys1110 and Asp1222,respectivily;on the other hand,the C-4phenoxy groups（B parts）formed one pi-pi interaction and the terminal benzene ring of the Z-25 can extend into the hydrophobic pocket.A series of 4-phenoxypyridine bearing quinoxalidone as c-Met kinase inhibitors were designed and synthesized,and the antitumor activity of the target compounds was studied in vitro.Enriching the structural of typeⅡc-Met kinase inhibitors and laid the foundation for further study of the optimal compounds.