[en] In the course of our investigations on Umutambasha in order to identify its convulsant principles, small quantities of monofluoroacetate were observed in stem bark, leaves, and fruits of this plant newly identified as Dichapetalum michelsonii Hauman. Conclusive evidence for a monofluoroacetate presence came from its isolation from the freeze-dried extract of stem bark. Three free unusual amino acids, named N-methyl-α-alanine, N-methyl-β-alanine, and 2,7-diaminooctan-1,8-dioic acid, described for the first time in a plant, and known trigonelline were also isolated from the stem bark of D. michelsonii. Structure elucidations were mainly achieved by spectroscopic methods (1H-NMR, 2D-NMR, MS) and by comparison with authentic references. These unusual amino acids were detected by a fast, reliable TLC analysis in all our batches of Umutambasha, suggesting that they could be used for identification purposes in case of human or livestock intoxications. Finally, EEG recordings and behavioural observations performed in mice suggested that the convulsive patterns produced by Umutambasha are the consequence of monofluoroacetate presence in D. michelsonii.
Research center :
Centre Interfacultaire de Recherche du Médicament CIRM Center for Cellular and Molecular Neurobiology CNCM
Disciplines :
Pharmacy, pharmacology & toxicology
Author, co-author :
Esters, Virginie ; Université de Liège - ULiège > Département de pharmacie > Pharmacognosie
Karangwa, Charles; Laboratory of Pharmacology and Toxicology, > Department of Pharmacy > Faculty of Medicine > National University of Rwanda, Butare, Rwanda
Tits, Monique ; Université de Liège - ULiège > Département de pharmacie > Phytochimie et phytothérapie
Francotte, Pierre ; Université de Liège - ULiège > Département de pharmacie > Chimie pharmaceutique
Pirotte, Bernard ; Université de Liège - ULiège > Département de pharmacie > Chimie pharmaceutique
Servais, Anne-Catherine ; Université de Liège - ULiège > Département de pharmacie > Analyse des médicaments
Fillet, Marianne ; Université de Liège - ULiège > Département de pharmacie > Analyse des médicaments
Crommen, Jacques ; Université de Liège - ULiège > Département de pharmacie > Département de pharmacie
Robbrecht, Elmar; Department of Vascular Plants (Spermatophyta-Pteridophyta) > National Botanic Garden of Belgium > Meise, Belgium
MINET, Arlette ; Centre Hospitalier Universitaire de Liège - CHU > Neurologie Sart Tilman
Grisar, Thierry ; Université de Liège - ULiège > Département des sciences biomédicales et précliniques > Département des sciences biomédicales et précliniques
Angenot, Luc ; Université de Liège - ULiège > Département de pharmacie > Département de pharmacie
Frederich, Michel ; Université de Liège - ULiège > Département de pharmacie > Pharmacognosie
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