Artifactual generation of an alkaloid in the course of Mondia whitei (Hook.f.) Skeels roots extraction: A clue to endogenous-formed bioactive compounds?
Abstract Introduction The roots of Mondia whitei (Hook.f.) Skeels are widely used across Africa for the treatment of depression, asthenia and sexual disorders. The botanical family Apocynaceae infers the possible presence of alkaloids, which could be responsible for the reported biological properties. Methods Preparation of raw alkaloids extracts induced a reaction between a compound of the root and ammonia, yielding an alkaloid artifact. The precursor and reaction product were identified by HPLC–UV–ESI-MS. The precursor's reactivity toward neurotransmitters was investigated to highlight a possible mechanism of action of M. whitei . Results The compound 2-hydroxy-4-methoxybenzaldehyde was identified as the artifactual alkaloid precursor. Its isomers (vanillin and isovanillin) do not show detectable reactivity toward ammonia. Mass spectrometry and TLC analyses confirmed the reactivity of 2-hydroxy-4-methoxybenzaldehyde toward dopamine, γ-aminobutyric acid, norepinephrine and serotonin. Conclusion M. whitei contains a molecule, 2-hydroxy-4-methoxybenzaldehyde, able to generate alkaloid artifacts by reaction with the neurotransmitters dopamine, γ-aminobutyric acid, norepinephrine and serotonin; these stable derivatives might explain the root's alleged bioactivity.