IDENTIFICATION OF SECONDARY METABOLITES IN SELECTED INDIGENOUS PLANT MATERIALS AND THEIR POTENTIALS FOR STORAGE INSECT PEST MANAGEMENT

Abstract

The study screened the phytochemical compounds in Ocimum basilicum L. whole plant, Senna siamea (Lam.) and Ficus polita Vahl stembark and provided information on their potentials for storage insect pest management. The plant materials were sourced locally in Gombe and environs subsequently identified at the Biological Sciences Department, Faculty of Science, Federal University of Kashere. Gas ChromatographyMass Spectrometry (GC-MS) using three (3) different extraction solvents (Ethanol,  Methanol and Water) was employed for the laboratory screening. Ethanol extracts of  O.  basilicum revealed 68.28% Fatty acids, 10.37% Esters and 5.74% Terpenoid. Methanol extracts showed 63.61% Fatty acids, 5.15% Terpenes and 3.75% Carboxylic acids. Water extracts revealed 20.59% Siloxanes, 5.61% Steroids and 4.65% Ethers. S. siamea ethanol extracts revealed 17.94% Esters, 16.44% Fatty acids, 13.18% Acetates and 12.88% Alcohols. Methanol extracts revealed 26.01% Siloxanes, 15.72% Fatty acids and 9.41% Alcohols. Water extracts revealed 42.11% Fatty acids and 6.67% Heterocyclic in S. siamea stembark. Ficus.  polita ethanol extracts showed 43.07% Terpenoids, 29.34% Sesquiterpenes and 4.91% Phenols. The methanol extracts revealed 56.47% Terpenoids, 10.04% Amines, 9.10% Heterocycles and 7.62% Sterols, while water extracts revealed 43.12% Steroids, 23.90% Esters and 11.85% Terpenoids in F. polita stembark. Plant secondary metabolites are linked to insecticidal activities of plants. Many plant materials contained insecticidal properties such as repellant, antifeedant, oviposition deterrent, growth inhibition either as contact toxicity or fumigant.  Studies have indicated terpenoids as major examples of insecticide substances, hence,  plants secondary metabolites could serve as good alternatives to chemical insecticides.