(1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-9-(2-Carboxymethoxy-ethanoyloxy)-1-isopropenyl-5a,5b,8,8,11a-pentamethyl-eicosahydro-cyclopenta[a]chrysene-3a-carboxylic acid 3-O-(3'-Glyoryl)betulinic acid AIDS-028532 AIDS028532 Betulin der.