Conformationnally restricted naphthalene derivatives type isocombretastatin A-4 and isoerianin analogues: synthesis, cytotoxicity and antitubulin activity.

A novel series of dihydronaphtalene, tetrahydronaphtalene and naphtalene derivatives as restricted analogues of isoCA-4 were designed, synthesized and evaluated for their anticancer properties. High cell growth inhibition against four tumour cell lines was observed at a nanomolar level with dihydronaphtalenes 1d, e and 1h, tetrahydronaphtalene 2c and naphtalene 3c. Structure-activity relationships are also considered. These compounds exhibited a significant inhibitory activity toward tubulin polymerization (IC(50) = 2-3 μM), comparable to that of isoCA-4. The effect of the lead compounds 1e and 2c on the cancer cells tested was associated with cell cycle arrest in the G(2)/M phase. Docking studies reveal that these compounds showed a binding mode similar to those observed with their non-constraint isoCA-4 and isoerianin congeners.