Synthesis and human immunodeficiency virus (HIV)-1 protease inhibitory activity of tripeptide analogues containing a dioxoethylene moiety.

Tripeptide analogues 2 and 3 containing a dioxoethylene moiety were designed based on the characteristic structure of the naturally occurring human immunodeficiency virus (HIV)-1 protease inhibitors RPI-856 A, B, C and D (1). The compounds (2, 3) prepared showed high inhibitory activity, comparable to that of RPI-856 A, against HIV-1 protease in vitro.