(organic chemistry) The diterpenoid lactone (1S,3R,6S,9R,12S,13S,14R,15S)-1-(furan-3-yl)-13-hydroxy-6,12,14-trimethyl-2,4,10,16-tetraoxapentacyclo[11.3.1.0^(3,15).0^(6,15).0^(9,14)]heptadec-7-ene-5,11-dione