Biological activity and secondary metabolite profile of Ruta graveolens leaves against maize weevil infestations
AGWU Perera, MMSC Karunaratne and SDM Chinthaka
The present phytocentric study provides the first investigation on volatile profile, chemical composition and bioactivity of Ruta graveolens (Aruda) leaves against the maize weevil, Sitophilus zeamais (Motschulsky). The volatile organic compound (VOC) profile of fresh leaves of R. graveolens was analyzed with HS-SPME/GC-MS and phytochemical screening was also performed. In addition, insecticidal and repellent properties of R. graveolens were also evaluated in both contact and vapor forms. A total of 45 compounds representing approximately 93% of the total quantum were detected in R. graveolens leaves consisting mainly of 2-ketones. Aqueous leaf extract exhibited the presence for majority of phytoconstituents while hexane demonstrating the least. Data on insecticidal potential and repellency against S. zeamais indicated strong maize grain protection activities. Present study provides the evidence that R. graveolens leaves contain agriculturally important bioactive secondary plant metabolites, justifying the use of plant species against S. zeamais in storage pest management programs.