Isolation and lipolytic activity of eurycomanone and its epoxy derivative from Eurycoma longifolia

Eurycomanone (1) and 13β,21-epoxyeurycomanone (2) were isolated from Eurycoma longifolia for studies of lipolytic activity. Compound 1 enhanced lipolysis in adipocytes with an EC₅₀ of 14.6μM, while its epoxy derivate, compound 2, had a stronger activity with an EC₅₀ of 8.6μM. Based on molecular mechanistic study using several specific inhibitors to lipolytic signaling pathways, it was found that PKA inhibitor totally diminished the lipolytic activity of 1 and 2. Further immunoblotting analysis confirmed the activation of phosphorylated PKA by both 1 and 2. With the growing need to develop new anti-obesity agents, eurycomanone and its epoxy derivate can be used as promising lead compounds to target lipid catabolism.