4-[N-(1-{N-[1-(N-{[N-((3E)(1S)-1-Ethyl-2-oxopent-3-enyl)carbamoyl](1S)cyclohexylmethyl}carbamoyl)(1S)-2-methylbutyl]carbamoyl}(1S)-3-methylbutyl)carbamoyl](4R)-4-[(2S)-2-(acetylamino)-3-carboxypropanoylamino]butanoic acid AIDS-169905 AIDS169905