(R)-N-((S)-1-{(2R,3S)-3-[(1-Benzyl-2-methyl-propylcarbamoyl)-methyl]-oxiranyl}-2-phenyl-ethyl)-2-(3-butyl-3-methyl-ureido)-3-methanesulfonyl-3-methyl-butyramide AIDS-045209 AIDS045209 BuNHCO(MeSO2-Val)Phe Epoxy deriv.