| Enterovirus 71(EV71)belongs to the genus Enterovirus of family Picornaviridae.The viruse is common cause of hand,foot,and mouth disease(HFMD),which mostly affects young children.Clinical treatments are directed only toward relieving the most prominent symptoms of each clinical syndrome.Therefore,we need to develop novel EV71 inhibitors.In past decades,some targets were found,such as VP1 and 3C protease.VP1 was identified as the major receptor-binding protein to block virus entry,and 3C protainase is the key protease for EV71 protein synthesis.This thesis reported that we used CADD methods to develop antivirals against EV71.On the one hand we found that EV71 VP1 showed a high nucleotide sequence identity with HRV VP1.Based on the crystal structure of the EV71 capsid protein[Protein Data Bank(PDB)ID:3VBH],we screened our database using DOCK4.0 and Gold4.0.1 and found novel N-containing heterocyclic piperidines 9e as EV71 inhibitors(IC50=1.0μM,SI=513).9e was known to inhibit HRV.Our findings provide a basis for anti-EV71 drug development.On the other hand,we screened ACD,WDI and our database and found some candidates.EST-6 of these candidates demonstrated weak anti-EV71 activity in cell culture cytopathic effect assay.Some studies have shown that Cys147 can form irreversible covalently bond with EST-6.Based on this theory,we screened the fragment databases,such as CBD and our started material database.Then we selected some fragments that bonded tightly with the receptor in theory.These fragments were grown,connected with core structure and constructed a virtual database.We screened the virtual database again and designed 42 compounds with the structure of(2S,3S)-oxirane-2,3-dicarboxamide to synthesize.16 compounds of these 42 compounds showed anti-EV71 activity by using cell culture cytopathic effect assays.Compared with EST-6,the anti-EV71 activity of compound A12 was increased 1000-fold.Compound A12 had similar antiviral activity with positive control pirodavir and higher SI index.We also reported the enantiomeric excess(e.e.%)measuring method and result of the compound A14 to test the optical purity. |
