Related Experiment Video
Updated: Jul 17, 2026

Source and Route of Pyrrolizidine Alkaloid Contamination in Tea Samples
Published on: September 28, 2022
Phenylethylamine and piperidine alkaloids in aloe species
R J Nash1, J Beaumont, N C Veitch
1Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, U. K.
Abstract:
Of the approximately 300 species of ALOE (Liliaceae) native to Africa and Arabia, leaf extracts of 224 species have been examined chromatographically for alkaloids using ninhydrin, Dragendorff's reagent, nitroprusside, and iodoplatinate as revealing agents. From these, 48 (21%) species contained compounds giving a strong colorimetric reaction with at least one of these reagents. Tyramine derivatives were identified in 18 species and piperidine derivatives in a further 6 species. The other coloured zones remain unidentified but often appeared to represent common amino acids. Some taxonomic correlations are suggested. The presence of the toxic hemlock alkaloids in aloes readily available for potential medicinal use by local inhabitants sounds a note of caution against the unthinking use of these otherwise useful plants.
Related Concept Videos
Physical Properties of Amines
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
Amines: Introduction
Direct-Acting Cholinergic Agonists: Pharmacokinetics
Adrenergic Antagonists: Chemistry and Classification of ɑ-Receptor Blockers
Nonselective α-blockers: Nonselective α-blockers contain haloalkylamine or imidazoline moieties. Phenoxybenzamine, with a haloalkylamine...