Studies on the reactivity of CDDO, a promising new chemopreventive and chemotherapeutic agent: implications for a molecular mechanism of action.

CDDO, a semi-synthetic triterpenoid derived from oleanolic acid, has the potential to be used as a chemopreventive and chemotherapeutic agent. The structure of CDDO contains two alpha,beta-unsaturated carbonyl moieties, suggesting a mechanism of action involving a conjugate nucleophilic addition. Spectroscopic evaluation with thiol nucleophiles illustrates that an addition does indeed occur, but this addition is selective and reversible.