Van Elst, DaanVan Wyk, BraamSchultz, AnitraPrinsen, Els2013-05-062013-05-062013-01Van Elst, D, Van Wyk, B, Schultz, A & Prinsen, E 2013, 'Production of toxic pavettamine and pavettamine conjugates in the gousiekte-causing Fadogia homblei plant and its relation to the bacterial endosymbiont', Phytochemistry, vol. 85, no. 1, pp. 92-98.0031-9422 (print)1873-3700 (online)10.1016/j.phytochem.2012.08.025http://hdl.handle.net/2263/21443Plant poisoning of livestock is responsible for considerable economic losses in southern Africa. Six plant species of the Rubiaceae family are known to cause gousiekte, a cardiac syndrome of ruminants induced by ingestion of the toxic compound pavettamine. Progress in understanding the aetiology of this disease is largely hampered by the variable toxicity of the plants and the absence of a quantification method for pavettamine. The pavettamine concentration in leaf samples of Fadogia homblei, a known gousiekte causing plant, was analyzed by massspectrometry. In the most apical leaf pair, the highest concentration of pavettamine was detected. Distal leaves contained progressively less pavettamine. Besides a significant amount of free pavettamine, most pavettamine was found to occur in a conjugated form. To which molecules the pavettamine is conjugated remains unknown as is the function of conjugated pavettamine in the development of gousiekte. All know gousiekte-causing plants contain symbiotic bacteria in their leaves; it was hypothesized that these bacteria might be involved in the production of pavettamine. However, analysis of in vitro cultures of the Fadogia homblei endosymbiont revealed no production of pavettamine. Pavettamine is therefore not produced by the bacteria alone. It is either the product of the interaction with the plant or solely produced by the host.en© 2013 Elsevier. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Phytochemistry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Phytochemistry, vol. 85, no. 1, 2013, DOI : 10.1016/j.phytochem.2012.08.025Fadogia hombleiRubiaceaeBurkholderiaEndosymbiontMass-spectrometryPavettamineGousiektePostprint Article