(1R,3aS,5aR,5bR,7aR,11aR,11bR,13aR,13bR)-1-Isopropenyl-5a,5b,8,8,11a-pentamethyl-9-oxo-eicosahydro-cyclopenta[a]chrysene-3a-carboxylic acid 3-Deoxy-3-oxo-betulinic acid 4481-62-3 AIDS-051817 AIDS051817 Betulonic acid