Chemical construction and anti-HCoV-OC43 evaluation of novel 10,12-disubstituted aloperine derivatives as dual cofactor inhibitors of TMPRSS2 and SR-B1

Thirty-one new 10,12-disubstituted aloperine derivatives were subtly constructed through a selective oxidation on the 10-α-C-H induced by sulfonyl and a nucleophilic substitution with the stereoselectivity and scalability.Of them,compound 6b displayed a moderate anti-human coronavirus OC43(HCoV-OC43)potency and blocked the viral entry stage through a host mechanism of action.Using chemoproteomic techniques,both transmembrane serine protease 2(TMPRSS2)and scavenger receptor class B type 1(SR-B1)proteins,which act as host cofactors of viral entry,were identified to be the direct targets of 6b against HCoV-OC43.Furthermore,6b may deactivate the TMPRSS2 by inducing a change in protein conformation,rather than binding to its catalytic center,thus suppressing the viral membrane fusion.Accordingly,our study provided key scientific data for the development of aloperine derivatives into a new class of antiviral candidates against humanβ-coronavirus,including severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).