(1-{(1S,3S)-1-Benzyl-2-hydroxy-3-[3-methyl-2-(pyridin-4-ylmethoxycarbonylamino)-butanoylamino]-4-phenyl-butylcarbamoyl}-2-methyl-propyl)-carbamic acid pyridin-4-ylmethyl ester AIDS-045723 AIDS045723 Mono-ol-based HIV Protease inhibitor Derivative