The molecule is an alkaloid isolated from the marine sponge Neopetrosia exigua which acts as a potent inhibitor of indoleamine 2,3-dioxygenase.
(12R)-16-(2-aminoethyl)-9-hydroxy-1',3',6,6-tetramethylspiro[11-oxa-18-aza-6-azoniapentacyclo[11.7.0.02,10.03,7.015,19]icosa-1(13),2,7,9,15(19),16-hexaene-12,5'-imidazolidine]-2',4',14,20-tetrone