Pharmacognosy of Allamanda bark drugs

Abstract

Bark samples of Allamanda cathartica L. (Apocynaceae), an indigenous drug of India, Philippines, etc. have been studied. Chemical, histochemical, anatomical, macromorphological and other pharmacognostic information (e.g. ash value, powder study, fluorescence, etc.) has been given. The bark drugs of the species can be distinguished from those of the allied species A. blanchetlii A.DC. by size and frequency of lenticels, cork-anatomy, number of phelloderm layers, size of starch grains, nature of pericyclic fibre patchés, depth of secondary phloem. Diagnostic features are: undulated wall of cork cells, absence of latex tubes (cells present), uniformly distributed rhomboidal crystals, positive reactions to alkaloidal and glycosidal tests, dirty green fluorescence of straw-coloured aqueous extracts, and blackish orange fluorescence of brownish yellow alcoholic extracts.