Piperlonguminine is a known alkaloid amide from peppers, including Piper divaricatum. Acts as a potent anticancer agent. Displays inhibitory effect on alpha-melanocyte-stimulating hormone (alpha-MSH)-induced melanogenesis in melanoma B16 cells (IC₅₀= 9.6 µM). The mode of action is through the inhibition of alpha-MSH-induced tyrosinase synthesis.