PHARMACOGNOSY, Phytochemical Examination of the Plant species of Aframomum danielli and A. spectrum

ABSTRACT

     Aframomum danielli and Aframomum sceptrum (Zingiberaceae) have been studied in this research project for their phytochemical constituents, thin layer chromatographic analysis and insecticidal potentials.

    Phytochemical examination of the dried fruits showed the presence of alkaloids, terpenes, tannins and flavonoids. Saponin glycosides, cardiac glycosides, anthraquinone glycosides and cyanogenetic glycosides were absent in both plant species.

    The chromatographic analysis using chloroform: Methanol (9:1) revealed the presence of alkaloids and compounds of anti-oxidant properties in both plant species.

     The powdered seeds extracts of Aframomum danielli gave the greatest insecticidal activity as it killed Callosobruchus maculatus (cowpea weevils) within a short period of time for a slow as an effective concentration as 20% and it showed an insecticidal activity of more than 75%. The extracts of the powdered husks of Aframomum danielli also showed considerable insecticidal activity as about 51% and not as pronounced as the extracts of its powdered seeds.

     The extracts of the powdered seeds of Aframomum sceptrum also showed significant insecticidal activity of about 64%,which was more pronounced than the insecticidal effect found in the extracts of the powdered husks of Aframomum danielli, but not as effective as the extracts of the powdered seeds of Aframomum danielli.

    The extracts of the powdered husks of Aframomum sceptrum showed a very poor insecticidal activity (less than 40%) against Callosobruchus.

    Thus, in the descending order of insecticidal activity, it could be seen that extracts of powdered seeds of Aframomum danielli showed the greatest insecticidal activity followed by extracts of the powdered seeds of Aframomum sceptrum, the extracts of the powdered husks of Aframomumdanielli, and eventually the extracts of the powdered husks of Aframomum sceptrum with least insecticidal activity.