AIDS-031268 AIDS031268 NSC337783 Phenanthro[1,2-b]oxirene-4-carboxylic acid, 1a,1b,2,3,3a,4,5,6,7,7a,9,9a-dodecahydro-1b-hydroxy-4,7a-dimethyl-9a-(1-methylethyl)-9-oxo-, methyl ester, (1aS,1bS,3aR,4R,7aS,9aS)- Triptolide Analog