(1R,3aR,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bS)-1-Acetyl-3a,5a,5b,8,8,11a-hexamethylicosahydro-1H-cyclopenta[a]chrysen-9-yl acetate 3-Acetoxynorlupen-2-one AIDS-113957 AIDS113957