Ginkgolide C,1,7-Dihydroxy-ginkgolide A

(1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11R,11aR)-3-(1,1-Dimethylethyl)hexahydro-2,4,7b,11-tetrahydroxy-8-methyl-9H-1,7a-(epoxymethano)-1H,6aH-cyclopenta[c]furo[2,3-b]furo[3',2':3,4]cyclopenta[1,2-d]furan-5,9,12(4H)-trione