Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The Gum of Fagara xanthoxyloides


Fagara xanthoxyloides Lam. (Xanthoxylum Senegalense DC.), a common plant in West Africa, exudes a clear yellow gum during the dry season. The gum is partly acetylated and has a significant methoxyl content. A single unpurified nodule gave, on analysis, acetyl groups, 6.95 per cent; methoxyl groups, 2.6 per cent. The nodules dissolve with difficulty in water to give a viscous solution with a faintly acid reaction. The purified gum was obtained in the usual way1, and after drying in a partial vacuum at 30° was a white amorphous powder,[α]21D + 4° (c. 0.5 in N sodium hydroxide); equivalent weight by direct titration, 1,100; sulphated ash, 0.25 per cent; nitrogen, 0.23 per cent; acetyl groups, none; methoxyl groups, 2.6 per cent (a polysaccharide of equivalent weight 1,100 containing monomethyl-hexuronic residues would have a methoxyl content of 2.8 per cent). It gave a positive naphthoresorcinol test for uronic acid, and failed to reduce Fehling's solution. Specimens prepared from nodules from different trees did not show any significant differences in optical rotations and equivalent weights, indicating the essential homogeneity of the gum.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout


  1. Smith, J. Chem. Soc., 744 (1939).

  2. Hough, Jones, and Wadman, J. Chem. Soc., 796 (1952).

  3. Andrews, Hough, and Jones, J. Chem. Soc., 1186 (1953).

  4. Hirst, and Jones, J. Chem. Soc., 1659 (1949).

  5. Hirst, and Perlin, J. Chem. Soc., 2622 (1954).

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

TORTO, F. The Gum of Fagara xanthoxyloides. Nature 180, 864–865 (1957).

Download citation

  • Issue Date:

  • DOI:


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing