Oleanolic acid suppress transcription or translation of inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2) genes. is extracted from the reference, compound 12a. For the transformation of olefin 9a into ketone 12a , the obvious ozonolysis cannot be used because ozone also reacts with the C-12 olefin of oleanane triterpenoids to give the 12R,13R-epoxide, 12-ketone,9 and 12R-hydroxy lactone..