Induction of apoptosis by photoexcited tetracyclic compounds derivatives of benzo[b]thiophenes and pyridines.

The antiproliferative activity, upon UVA irradiation, of two tetracyclic derivatives of benzo[b]thiophenes and pyridines, a benzo[b]thienopyridopyrimidone (1) and a thienocarboline (2), has been investigated in a panel of human tumor cell lines. The two compounds present a remarkable cytotoxicity after UVA irradiation (365nm), reaching an IC50 of 0.1μM in the leukaemia cell lines and 0.3–0.5μM in the solid tumour cell lines.