Anti-austeritic Constituents of the Congolese Medicinal Plant Aframomum melegueta.

In the course of our search for anticancer agents based on a novel anti-austerity strategy, we found that the CHCl3 extract of the roots of Aflamomum melegueta (Zingiberaceae), collected in the Democratic Republic of Congo, killed PANC-1 human pancreatic cancer cells preferentially in nutrient-deprived medium (NDM). Phytochemical investigation of the CHCl3 extract led to the isolation of seven known compounds [(-)-buplerol (1), (-)-arctigenin (2), (E)-14-hydroxy-15-norlabda-8(17),12-dien-16-al (3), labda-8(17),12-dien-15,16-dial (4), 16-oxo-8(17),12(E)-labdadien-15-oic acid (5), 5-hydroxy-7-methoxyflavone (6), and apigenin (7)]. In addition to the previously reported preferentially cytotoxic compound, (-)-arctigenin (2, PC50 0.5 μM), (-)-buplerol (1) also displayed potent preferential cytotoxicity with a PC50 value of 8.42 μM and triggered apoptosis-like PANC-1 cell death in NDM.