Amauromine, a symmetric bis-dihydroindole, was first isolated from Amauroascus sp. by researchers at Fujisawa (now Astellas) in 1984 as a potent vasodilator. Amauromine has two prenylated dihydroindoles coupled through their respective 2- and 3-positions to a central diketopiperazine. Amauromine was later reported as a secondary metabolite in a related genus, Auxarthron, and its anamorphic genus, Malbranchea. Amauromine is a potent inhibitor of cannabinoid CB1 receptors with antagonistic activity at the cannabinoid-like orphan receptor GPR18.