Synthesis of novel strobilurin-pyrimidine derivatives and their antiproliferative activity against human cancer cell lines.

A series of new strobilurin-pyrimidine analogs were designed and synthesized based on the structures of our previously discovered antiproliferative compounds I and II. Biological evaluation with two human cancer cell lines (A549 and HL60) showed that most of these compounds possessed moderate to potent antiproliferative activity. Two potent candidates (8f, IC50=2.2 nM and 11d, IC50=3.4 nM) were identified with nanomolar activity against leukemia cancer cell line HL60 for further development. This activity represents a 1000- to 2500-fold improvement compared to the parent compounds I and II and is 20- to 30-fold better than the chemotherapy drug, doxorubicin. The present work provides strong incentive for further development of these strobilurin-pyrimidine analogs as potential antitumor agents for the treatment of leukemia.