The molecule is a sesquiterpene lactone isolated from the whole plants of Ainsliaea macrocephala; exhibits inhibitory activity against production of nitric oxide (NO). It has a role as a metabolite and an EC 1.14.13.39 (nitric oxide synthase) inhibitor. It is a spiro compound and a sesquiterpene lactone.
(1S,2S,3'aS,6S,6'aR,9'aR,9'bS,10R,12S,13R,16S)-12,16-dihydroxy-3',5,6',9-tetramethylidenespiro[3-oxatetracyclo[8.6.0.02,6.012,16]hexadecane-13,9'-4,5,6a,7,9a,9b-hexahydro-3aH-azuleno[4,5-b]furan]-2',4,8'-trione