Synthesis and biological activity of desmethoxy analogues of coruscanone A

A series of simple desmethoxy analogues of coruscanone A was prepared via a novel version of Ti(iPrO)(4)-mediated Knoevenagel condensation of cyclopentenedione with substituted benzaldehydes and cinnamic aldehydes, and the compounds were evaluated for antifungal activity and cytotoxicity. The most potent 2-benzylidenecyclopent-4-ene-1,3-dione possessed antifungal effect comparable to coruscanone A and a somewhat broader spectrum of activity against Candida species. The compound was also superior to fluconazole against several non-albicans Candida sp. Evaluation of the ability of the compound to influence cell proliferation using two different assays showed that 2-benzylidenecyclopent-4-ene-1,3-dione has lower cytotoxicity compared to the natural product.