We report the synthesis and evaluation as potential anticancer agents of a series of tetracyclic indenoquinolines. The compounds, which are obtained through the photoisomerization of Diels–Alder adducts formed between purpurogallin derivatives and nitrosobenzene, have in vitro antiproliferative activities in the μM to nM range against breast (MCF-7), lung epithelial (A-549), and cervical (HeLa) adenocarcinoma cells. The ...