VOLUME 19 NUMBER 1 (January to June 2026)

Gas chromatography, molecular docking analysis, and insecticidal activity assessment of Kamamba (Piper umbellatum L.) crude leaf extract against maize weevil (Sitophilus zeamais)

Kamamba (Piper umbellatum L.) is a tropical shrub native to Central and South American countries. It is known in other tropical countries outside America for its various culinary and folk medicinal applications. Several researchers are exploring other use of the different plant parts of P. umbellatum L., such as in pest management. In this study, an ethanolic extract of P. umbellatum L. leaves was analyzed through GC-MS for identification of compounds and tested through contact/residual bioassay for mortality against maize weevil (Sitophilus zeamais). Further evaluation using molecular docking with AutoDock 4 was performed to better understand the probable mode of action and explain the mortality observed in the bioassay. GC-MS results showed the presence of phenols, esters, sugar derivatives, and other volatile organic compounds. LC50 of 478.60 mL/L (volume of extract per liter of treatment solution) was calculated through probit analysis, indicating relatively low potency under the assay conditions. The result of molecular docking indicates possible mode of action of the compounds through inhibition of acetylcholinesterase or agonism of octopamine receptor. 2,3-dihydrobenzofuran was noted as the promising compound responsible for the insecticidal activity observed for its promising interactions with both acetylcholinesterase and octopamine receptor. These results suggest neurotoxic activity of the P. umbellatum L. leaf extract to S. zeamais.