AIDS-028540 AIDS028540 Carbamic acid, [(1S,2S,4R,6E)-2-hydroxy-4-[[[(1S)-1-(1H-imidazol-2-yl)-2-methylpropyl]amino]carbonyl]-7-phenyl-1-(phenylmethyl)-6-heptenyl]-, 1,1-dimethylethyl ester PhCH=CH-Ala-Phe-HOCH2CH2 isostere analog SB-205078