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, g-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, g-aminobutyric acid, norepinephrine
and serotonin; these stable derivatives might explain the root’s alleged bioactivity.