Oleanolic acid derivative 2 is an oleanolic acid derivative, which is a novel triterpenoid-steroid hybrid molecule. In Vitro: Oleanolic acid suppress transcription or translation of inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2) genes. HY-18003 is extracted from the reference, compound 12a. For the transformation of olefin 9a (HY-18002) into ketone 12a (HY-18003), 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.^[1].