Novel quinazoline–quinoline alkaloids with cytotoxic and DNA topoisomerase II inhibitory activities

Two new synthetic analogues of luotonins A and F, 7-acetylaminoluotonin A (6) and 3-[3H(quinazolino-4-one)]quinoline (7) were synthesized. The new analogues, along with four natural quinazoline–quinoline alkaloids, luotonins A (1), B (2), E (3), F (4) and a synthetic deoxoluotonin F (5), showed cytotoxic activity (IC50 1.8–40.0 μg/mL) and DNA topoisomerase II inhibition at a concentration of 25 μM.