PHENYLETHYLAMINE AND PIPERIDINE ALKALOIDS IN ALOE SPECIES

Of the approximately 300 species of Aloe (Liliaceae) native to Africa and Arabia, leaf extracts of 224 species have been examined chromatogr aphically for alkaloids using ninhydrin, Dragendorff's reagent, nitrop russide, and iodoplatinate as revealing agents. From these, 48 (21%) s pecies contained compounds giving a strong colorimetric reaction with at least one of these reagents. Tyramine derivatives were identified i n 18 species and piperidine derivatives in a further 6 species. The ot her coloured zones remain unidentified but often appeared to represent common amino acids. Some taxonomic correlations are suggested. The pr esence of the toxic hemlock alkaloids in aloes readily available for p otential medicinal use by local inhabitants sounds a note of caution a gainst the unthinking use of these otherwise useful plants.