Design And Synthesis Of Membrane Protein Cathepsin L Dual-Traget Inhibitor

Ebola virus,Marbug virus,SARS and SARS-COV-2 are very important viruses that seriously affect human health.The development of their therapeutic drugs is very important.The current inhibitors are mainly entry inhibitors,reverse transcriptase inhibitors,synthase inhibitors and protease inhibitors,which inhibit the entry,transcription,replication and release of viruses by targeting viral proteins or proteins and enzymes that interact with viral proteins.The envelope protein GP or spike protein(S)is the key protein for the four viruses to enter the target cell.Cathepsin L(Cat L)cleaves GP(S)to promote the exposure of the receptor binding region.Polypeptide fusion inhibitors,such as EK1,HR2 P,EK1C4,IPB02 and IPB01,have been developed to target membrane protein(GP),but no inhibitor enters clinical uses.Recently,Cat L inhibitors have been widely investigated,the compound K777 has entered clinical trial as a broad-spectrum antiviral drug.However,the above-mentioned viruses enter target cells by endocytosis,and a single fusion inhibitor is difficult to interact effectively with GP protein.At present,the inhibitory activity of single fusion polypeptide inhibitors against SARS,EboV,Mar V and SARS-COV-2 is not high(μmol level).In order to improve the inhibitory activity of inhibitors against the four viruses mentioned above,this thesis designed and synthesized membrane protein-cathepsin bifunctional inhibitors,in which Cat L inhibitors not only inhibit Cat L,but also bring fusion peptides into cells to interact with viral protein GP,so that they might display highly inhibitory activity.In this thesis,we selected the high activity fusion polypeptide inhibitors of EboV,Mar V,SARS,SARS-COV-2 that we found previously or were reported in the literature,and modified the C-terminal with lysine-containing alkynyl.In the other hand,we synthesized Cat L inhibitor K777 derivative modified by azidoacetic acid,and then applied click reaction to couple fusion inhibitor and the K777 derivative to synthesize GP-Cat L double target inhibitor.In order to compare the reactivity and mechanism of dual-target inhibitors,the highly active fusion polypeptide inhibitors,NHR peptides and Cat L K777 were synthesized.The main results of this paper are as follows:(1)The positive compound Cat L inhibitor K777 was synthesized and some reaction routes were optimized;(2)The derivative of K777 containing azide was synthesized;(3)Fmoc-butynyl K was synthesized,which was used to couple fusion peptide inhibitor into K777 derivative;(4)21 peptide fusion inhibitors or NHR peptides were synthesized,9 peptides were the positive fusion inhibitors of EboV,Mar V,SARS,SARS-COV-2,12 peptides were the peptide fusion inhibitors containing butynyl K,and 3 peptides were NHR positive peptides;(5)10 novel GP-Cat L double target inhibitors were synthesized,Five of the double target inhibitors were identified correctly by mass spectrometry.This work lays a foundation for the research and development of antivirus compounds of coronavirus and filovirus including Ebola,Marburg and SARS...