Chemistry & biodiversity
December 1, 2016
Felix Krengel, Josefina Herrera Santoyo, Teresa de Jesús Olivera Flores et al.
19 citations
Ten monoterpenoid indole alkaloids and one simple indole alkaloid were identified for the first time in Tabernaemontana alba and Tabernaemontana arborea, two Mexican medicinal plants. The anti-addiction compounds ibogaine and voacangine were found in most wild and greenhouse-grown whole plants, with highest concentrations in stem and root barks. Whole plants of T. alba were regenerated from leaf callus via somatic embryogenesis, but no alkaloids were detected in the callus itself. The species are potentially viable sources of ibogaine and voacangine, and approaches to increase alkaloid yields in plants and cell cultures are discussed.
Chemistry & biodiversity
July 1, 2019
Felix Krengel, Marco V Mijangos, Marisol Reyes-Lezama et al.
17 citations
Methanol effectively extracts the antiaddictive alkaloids coronaridine, ibogamine, voacangine, and ibogaine (the CIVI-complex) from the root barks of Mexican Tabernaemontana alba and Tabernaemontana arborea. A one-step demethoxycarbonylation process then converts coronaridine and voacangine directly into ibogamine and ibogaine, simplifying the mixture from four to two major compounds. This protocol improves qualitative and quantitative analysis and offers a viable method for bulk production of these therapeutically important substances from these promising plant sources.
Neurotoxicology
March 1, 2022
María Eva González-Trujano, Felix Krengel, Ricardo Reyes-Chilpa et al.
14 citations
A hydroalcoholic extract of Tabernaemontana arborea and its alkaloids ibogaine and voacangine altered brain electrical activity in mice. The extract at 56.2 and 100 mg/kg and ibogaine at 30 mg/kg increased delta and reduced alpha EEG band power, indicating central nervous system depression. Voacangine at 30 mg/kg flattened EEG patterns. None of the treatments modified seizures induced by pentylenetetrazole, but the extract at 100 mg/kg combined with the convulsant caused sudden death. Paroxysmal EEG activity from the extract and ibogaine was explored; a serotonin 5-HT1A receptor antagonist blocked the extract's but not ibogaine's paroxysmal activity, implicating serotonin neurotransmission in the extract's excitatory effects.
Chemistry & biodiversity
April 1, 2019
Felix Krengel, Quentin Chevalier, Jonathan Dickinson et al.
10 citations
Ibogaine and related ibogan alkaloids, which show anti-addictive effects against drugs of abuse, occur in several Apocynaceae species. This work used gas chromatography-mass spectrometry and principal component analysis to compare alkaloid profiles of root and stem barks from four Mexican Tabernaemontana species with the root bark of the African shrub Tabernanthe iboga. Separation between species was attributed to quantitative differences in the major alkaloids coronaridine, ibogamine, voacangine, and ibogaine. T. iboga contained high concentrations of ibogaine, while Tabernaemontana samples showed predominance of either voacangine and ibogaine, or coronaridine and ibogamine. The results confirm that Mexican Tabernaemontana species are viable sources of anti-addictive compounds.
Chemistry & biodiversity
May 1, 2020
Felix Krengel, Jonathan Dickinson, Christopher Jenks et al.
7 citations
Gas chromatography-mass spectrometry (GC/MS) compared the alkaloid profiles of bark and leaf from one Mexican species (Tabernaemontana arborea) and one African species (T. crassa) with the primary commercial sources of semisynthetic ibogaine, Voacanga africana root and stem bark. The qualitative and quantitative similarities between T. arborea and V. africana barks support previous reports that T. arborea is a promising alternative source of voacangine and ibogaine. The results also suggest that T. crassa could be used to produce conopharyngine and ibogaline, two compounds with the same basic skeletal structure and possibly similar antiaddictive properties as ibogaine.
Planta medica
February 1, 2023
Julio César Carrero, Violeta Curay-Herrera, Lysette Chacón-niño et al.
6 citations
Alkaloids from the root bark of Tabernaemontana arborea, particularly ibogaine and voacangine, show potent anti-amoebic activity against Entamoeba histolytica trophozoites in culture, with IC50 values of 4.5 and 8.1 µM at 24 hours, comparable to metronidazole (6.8 µM). However, the effect diminished after 48 and 72 hours, suggesting the alkaloids may be catabolized into less active derivatives by the parasites. In a hamster model of amoebic liver abscess, the alkaloids reduced the number of trophozoites in liver tissue but did not prevent abscess formation, indicating rapid inactivation in vivo. The findings suggest potential for these compounds as leads for new amoebiasis treatments, though further work is needed to address metabolic instability.