Asterric acid is an antibiotic fungal metabolite that completely inhibits the binding of the potent vasoconstrictor endothelin (ET)-1 to the ETA receptor in A10 cells at 0.1 μM. Asterric acid derivatives have also been shown to inhibit VEGF-induced tube formation of human umbilical vein endothelial cells at 3-10 μM, which suggests its usefulness as an antiangiogenic agent.