As part of a preliminary chemophenetic study of the two genera of African ex. Acacia Mill. sensu lato (Senegalia Raf. and Vachellia Wight & Arn.), the distribution of alkaloids and amines was investigated with a focus on resolving unsubstantiated claims surrounding the existence of psychedelics in these genera. Nineteen of the 44 southern African taxa were screened, including eleven from Senegalia and eight from Vachellia. Lipophilic amine-specific extracts were produced from leaves, including other organs if available, then the extracts were studied by high performance liquid chromatography. The identities of four compounds were determined by nuclear magnetic resonance spectroscopy, i.e., tryptamine, N-methyltryptamine (NMT), N,N-dimethyltryptamine (DMT) and hordenine. With repeated sampling of select species (Senegalia ataxacantha (DC.) Kyal. & Boatwr., Senegalia caffra (Thunb.) P.J.H.Hurter & Mabb., and Senegalia polyacantha (Willd.) Seigler & Ebinger.) it was demonstrated that the chemistry varies intraspecifically, and potentially according to season or organ (flowers, bark, or leaves). It was observed that in South African biota from Gauteng province, tryptamines are detected in species from Senegalia, but not from Vachellia so far, representing a potential chemosystematic marker requiring further research. Only S. ataxacantha had quantifiable levels of the psychedelic amine DMT, occurring in the leaves and flowers at concentrations ranging from 0.01 to 0.05% (mass/mass, wet leaf weight). Quantifiable levels of DMT were detected in just one specimen from a single population, but not in others, or other populations sampled (aside from trace amounts). We conclude that further research is required to identify southern African genotypes of Senegalia and Vachellia with levels of small lipophilic amines and alkaloids high enough to be compared to the species used for psychedelic purposes in South America (1.0 > 0.2% of mass, wet leaf weight) and to identify quantifiable levels of tryptamines (>0.01% of mass, wet leaf weight) in species of Vachellia. We also emphasize that due to geographical chemical variation, our data cannot be compared to other parts of Africa, such as Egypt or other countries in eastern Africa.
