Synthesis and evaluation of pyrazolignans. A new class of cytotoxic agents

A series of fused pyrazole derivatives of cyclolignans have been prepared through simple chemical routes and evaluated for their cytotoxic activities in culture cells of P-388 murine leukemia, A-549 lung carcinoma and HT-29 colon carcinoma. Despite the lack of the lactone moiety in their structures, they show IC50 values at microM levels.