This invention describes novel tricyclic-bis-enone derivatives (TBEs), such as TBE-31, TBE-34, TBE-45 and water-soluble TBEs. The methods of preparing these compounds are also disclosed. The inventors demonstrate the ability of these new TBEs to inhibit proliferation of human myeloma cells, inhibit the induction of iNOS in cells stimulated with interferon-.gamma., induce heme oxygenase-1 (HO-1), induce CD11b expression--a leukemia differentiation marker, inhibit proliferation of leukemia cells, induce apoptosis in human lung cancer, and induce apoptosis in other cancerous cells. The TBEs of this invention are expected to be useful agents for the treatment and prevention of many diseases, including cancer, neurological disorders, inflammation, and pathologies involving oxidative stress.