as CD4mimics were previously reported as HIV-1 entryinhibitors that block the gp120–CD4 interaction and induce a conformational change in gp120, exposing its co-receptor-binding site. A structure–activity relationship (SAR) study of a series of CD4mimic analogs was conducted to investigate the contribution from the piperidine moiety of CD4mimic 1 to anti-HIV activity, cytotoxicity, and CD4 mimicry