Total Synthesis and Biological Evaluation of Moralbaflavone D

Moralbaflavone D (4) is a newly identified natural diprenylated flavonoid demonstrating cytotoxic activity. Herein, we report its first total synthesis, accomplished in only six steps with an overall yield of 5.1%. Key features in the synthesis included aryl ring prenylation, Claisen-Schmidt condensation, and intramolecular cyclization. Mechanistic studies have shown that 4 induces a G0/G1 phase arrest in a panel of cancer cell lines. The findings indicate that 4 exhibits moderate cytotoxic activity.