Acridone alkaloids as potent inhibitors of cathepsin V

In this work, we describe the inhibitory effects of acridone alkaloids isolated from Swinglea glutinosa a plant belonging to the Rutaceae family. This class of compounds showed to be potent inhibitors of the enzyme cathpesin V. Some of the alkaloids displayed IC50 values of inhibitory activity in the range of low μM. Mechanistic studies have clearly shown competitive inhibition with respect to substrate, with low dissociation constants: (2, Ki = 1.2 μM; 6, Ki = 1.0 μM; 7, Ki = 0.2 μM; and 11, Ki = 1.7 μM).