Acta Crystallographica Section C

Crystal Structure Communications

Volume 58, Part 3 (March 2002)


organic compounds



bk1627 scheme

Acta Cryst. (2002). C58, o195-o198    [ doi:10.1107/S0108270102000689 ]

Three ginkgolide hydrates from Ginkgo biloba L.: ginkgolide A monohydrate, ginkgolide C sesquihydrate and ginkgolide J dihydrate, all determined at 120 K

J.-P. Zhao, I. Muhammad, D. C. Dunbar, I. A. Khan, N. H. Fischer and F. R. Fronczek

Abstract: A low-temperature structure of ginkgolide A monohydrate, (1R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)-3-(1,1-dimethylethyl)-hexahydro-4,7b-dihydroxy-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 monohydrate, C20H24O9·H2O, obtained from Mo K[alpha] data, is a factor of three more precise than the previous room-temperature determination. A refinement of the ginkgolide A monohydrate structure with Cu K[alpha] data has allowed the assignment of the absolute configuration of the series of compounds. Ginkgolide C sesquihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11S,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 sesquihydrate, C20H24O11·1.5H2O, has two independent diterpene molecules, both of which exhibit intramolecular hydrogen bonding between OH groups. Ginkgolide J dihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)-3-(1,1-dimethylethyl)-hexahydro-2,4,7b-trihydroxy-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 dihydrate, C20H24O10·2H2O, has the same basic skeleton as the other ginkgolides, with its three OH groups having the same configurations as those in ginkgolide C. The conformations of the six five-membered rings are quite similar across ginkgolides A-C and J, except for the A and F rings of ginkgolide A.

Formula: C20H24O9·H2O, C20H24O11·1.5H2O and C20H24O10·2H2O


hkldisplay filedownload file

Structure factor file (CIF format) (203.1 kbytes)
Contains datablock I


hkldisplay filedownload file

Structure factor file (CIF format) (289.9 kbytes)
Contains datablock III


hkldisplay filedownload file

Structure factor file (CIF format) (132.3 kbytes)
Contains datablock IV


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