Synthesis and in vitro cytotoxic activity evaluation of novel heterocycle bridged carbothioamide type isosteviol derivatives as antitumor agents

Abstract: Two series of novel carbothioamide-substituted pyrazole and isoxazolidine derivatives were facilely prepared by functional interconversions in ring D of the tetracyclic diterpene isosteviol. The in vitro cytotoxic activities against four human tumor cell lines were evaluated. Our results indicated that carbothioamide-substituted pyrazole derivatives exhibited noteworthy cytotoxic activities. Specifically, compound 12p (IC50 =6.51μM) had the most potent cytotoxicity against Raji cell, which may be exploitable as a lead compound for the development of potent antitumor agents. [Copyright &y& Elsevier]