Acta Crystallographica Section E

Structure Reports Online

Volume 69, Part 8 (August 2013)

organic compounds

cv5419 scheme

Acta Cryst. (2013). E69, o1237-o1238    [ doi:10.1107/S1600536813018369 ]

Tenulin 0.25-hydrate, a sesquiterpene lactone isolated from Helenium amarum

K. S. Knight, C. T. Smith, T. G. Waddell and B. Noll

Abstract: The asymmetric unit of the title compound, C17H22O5·0.25H2O [systematic name: 2-hydroxy-2,2a,6,9a-tetramethyl-2a,4a,5,6,6a,9a,9b,9c-octahydro-2H-1,4-dioxadicyclopent[cd,f]azulene-3,9-dione 0.25-hydrate], a natural product isolated from Helenium amarum, contains two independent tenulin molecules and half a water molecule of crystallization situated on a twofold rotation axis. The hydroxy group of the hemiketal moiety is in a [beta]-position. In the crystal, each water molecule interacts with four tenulin molecules via O-H...O hydrogen bonds. The two independent tenulin molecules (A and B) differ only in the character of their participation in hydrogen bonding. Specifically, while A is an acceptor of Owater-H...OA and a donor of OA-H...OB hydrogen bonds, molecule B is an acceptor of the latter hydrogen bond and the donor of an OB-H...Owater hydrogen bond. In the crystal, these O-H...O hydrogen bonds link the tenulin and water molecules into layers parallel to the ac plane.

htmldisplay filedownload file

Hyper-Text Markup Language (HTML) file
[ doi:10.1107/S1600536813018369/cv5419sup0.html ]
Supplementary materials

cdxdisplay filedownload file

Chemdraw file (3.1 kbytes)
[ doi:10.1107/S1600536813018369/cv5419Isup3.cdx ]
Supplementary material


To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.

 bibliographic record in  format

  Find reference:   Volume   Page   
  Search:     From   to      Advanced search

Copyright © International Union of Crystallography
IUCr Webmaster