Rational Design,Chemical Synthesis And Biological Study Of ALK Inhibitors

Anaplastic lymphoma kinase?ALK?is a member of protein tyrosine kinase.In normal cells,ALK plays a significant role in the development of the brain and the nervous system.Mutations of ALK can lead to a lot of cancers.Up to date,various types of gene arrangements or mutations of ALK have been identified as oncogenic forms in several tumor types.Crizotinib which sever as the first generation of ALK inhibitor widely used in the treatment of NSCLC.However,the resistance to crizotinib was found within the first year or two after the treatment is initiated.Adverse effect of crizotinib cannot be neglected.We can not neglect that common untoward effects of crizotinib include hepatotoxicity,nephrotoxicity and visual disturbances had serious influence on patients.Considering the significance and limitation of crizotinib in cancer therapy and drug development,there is a need of new strategy to overcome the existing problems of crizotinib.In this study,we focus on the study of co-crystal structure of ALK in complex with crizotinib,and modify the chemical structure of crizotinib through Computer Aided Drug Design?CADD?.The well designed small molecules will go through biological tests.This work is expected to overcome a series of existing problems of crizotinib,such as drug-resistance and a series of adverse drug reaction.It also improves the activity of the ALK kinase inhibitor and provides a series of candidate drugs for clinical drug development.In this study,we use the method of replace fregment to design a series of small molecular compounds of diaryl ethyl ether,which performed by Discovery Studio.The chemical structure of crizotinib was divided into 3 parts,1-?4-piperidyl?pyrazole?Fragment A?,aminopyridine?Fragment B?and 3-fluoro-2,6-dichlorobezyloxyl?Fragment C?.Cystal structure of ALK kinase?PDB ID:2XP2?was used as receptor and the binding site for crizotinib was selected as active site.951 crizotinib analogues were generated after replacing the fragments.In order to get molecules with good pharmacokinetic properties and low toxicity,these molecules were screened using a module of ADMET descriptor to give 527 molecules,which were further docked with ALK using a module of CDOCKER and then ranked by CDOCKER energy.Finally,top 10 molecules were picked out for further studies.These molecules were subsequently screened using These compouds retained the aminopyridine ring part of crizotinib and increased the distance between the pyridine ring and the benzene ring.Molecular docking showed it was beneficial for interaction of compounds and ALK to increase the distance between pyridyl ring and phenyl ring in compounds.In this study,8 novel glycol diaryl ethers were synthesized by a series of Chemical reaction including N-acylation reaction,Miyaura borylation reaction,alkylation reaction,bromination reaction and Suzuki coupling reaction.Its structures were confirmed by NMR spectra and mass spectra.The in vitro anti-tumor activity of synthesized compounds was studied in NSCLC cell line H2228 and neurobalstoma cell line SH-SY5Y.Among the 8 novel glycol diaryl ethers compounds,25e exhibits stronger anti-cancer activity than crizotinib toward H2228 cell line with an IC₅₀ value of 0.22?mol/L.