1-[[5-{2-[(2-Benzyl-4-phenyl-butyryl)-methyl-amino]-3-methyl-butyrylamino}-6,6-dimethyl-4-oxo-2-(2-oxo-2-pyrrolidin-1-yl-ethyl)-heptanoylamino]-(1-ethyl-2,2-dimethyl-propylcarbamoyl)-methyl]-cyclopentanecarboxylic acid AIDS-191726 AIDS191726