Modern tools to analyse museum samples of curare and psychoactive preparations used by Amazonian tribes

Indigenous groups of the Amazonian rainforest have used a vast array of poisons and psychoactive drugs from plant origin for centuries. There is a great variety of different species used and each group has their own recipes to prepare plant mixtures [1]. Arrow poisons are made of alkaloids extracted mainly from the Menispermaceae (Chondrodendron spp.), as well as the Loganiaceae (Strychnos spp.). For shamanic ceremonies, Virola theiodora (Spruce ex Benth.) Warb., Banisteriopsis caapi (Spruce ex Griseb.) Morton, Psychotria viridis Ruiz & Pav.

and Anadenanthera peregrina (L.) Speg. are plants commonly used and known to produce psychoactive indole alkaloids.

Objects containing hunting poisons such as curare pots, blow gun darts, arrows, quivers, and ceremonial vessels enclosing powders with hallucinogenic constituents have been collected by museums like the Museum of Ethnography in Geneva for decades. To assess the chemical content of these nearly one hundred year old samples, analyses by ultra-high pressure chromatography – high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) were performed. The dereplication strategy was based on the creation of a molecular network [2], which groups molecules according to their structural similarities deduced from their MS/MS fragmentation pattern. A subsequent comparison of the experimental fragmentation spectra with an extensive in silico MS/MS database of natural products was performed [3]. The putative identification of constituents was then confirmed by injection of available standards. Bioactive compounds were detected in a majority of the 16 samples. D-tubocurarine and alkaloids encountered in the genus Strychnos were detected in curare preparations. N,N-Dimethyltryptamine (DMT) and derivatives such as bufotenine and 5-MeO-DMT were present in snuffs for shamanic ceremonies but also unexpectedly in arrow poisons. These results are valuable for curators who handle ancient collector's items which may still remain hazardous.

Keywords: Curare, hunting poison, natural product dereplication, molecular networking.

References:

[1] Prance G. The poisons and narcotics of the Amazonians Indians. J R Coll Physicians Lond 1999; 33: 368 – 376

[2] Yang JY, Sanchez LM, Rath CM, Liu X, Boudreau PD, Bruns N, Glukhov E, Wodtke A, de Felicio R, Fenner A, Wong WR, Linington RG, Zhang L, Debonsi HM, Gerwick WH, Dorrestein PC. Molecular networking as a dereplication strategy. J Nat Prod 2013; 76: 1686 – 1699

[3] Allard PM, Peresse T, Bisson J, Gindro K, Marcourt L, Pham VC, Roussi F, Litaudon M, Wolfender JL. Integration of molecular networking and in-silico MS/MS fragmentation for natural products dereplication. Anal Chem 2016; 88: 3317 – 3323