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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Mosquito and Fly Research » Research » Publications at this Location » Publication #385167

Research Project: Integrated Pest Management of Mosquitoes and Biting Flies

Location: Mosquito and Fly Research

Title: Chemical constituents from Rheum ribes shoots and its insecticidal activity against Aedes aegypti

item DEMIRAY, HATICE - Ege University
item Estep Iii, Alden
item Tabanca, Nurhayat
item BECNEL, JAMES - Retired ARS Employee
item DEMIRCI, BETUL - Anadolu Universtiy

Submitted to: Revista Brasileira de Farmacognosia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2021
Publication Date: 1/31/2022
Citation: Demiray, H., Estep III, A.S., Tabanca, N., Becnel, J.J., Demirci, B. 2022. Chemical constituents from Rheum ribes shoots and its insecticidal activity against Aedes aegypti. Revista Brasileira de Farmacognosia.

Interpretive Summary: Plants have provided many compounds of use as insecticides or as pharmaceuticals. In this study, which was part of a large Deployed Warfighter Protection Program effort to identify novel and safe natural insecticides, we isolated an extract from Rheum ribes, a type of rhubarb that grows natively in Turkey and then determined the components and the insecticidal activity of this extract. We found that as a whole, the extract resulted in mortality of the yellow fever mosquito but that the major component, palmitic acid, when tested in isolation, was much less active. This indicates that the activity of the extract is a synergistic result of several different compounds.

Technical Abstract: A phytochemical investigation of n-hexane extract of Rheum ribes L. (Polygonaceae) shoots was analyzed by GC-FID and GC-MS and revealed seven components including methyl hexadecanoate (methyl palmitate)(2.4%), (Z)-9-methyl octadecenoate (methyl oleate) (2.9%), (Z,Z)-9,12-methyl octadecadienoate (methyl linoleate) (5.7%), (Z,Z,Z)-9,12,15-methyl octadecatrienoate (methyl linolenate) (3.5%), 1-octadecanol (4.3%), heptacosane (13.5%) and hexadecanoic acid (palmitic acid) (67.7%). The n-hexane extract of R. ribes was bioassayed for larvicidal and adult topical activity against an insecticide susceptible strain of Aedes aegypti. Results showed that the n-hexane extract demonstrated 90% mortality against adult Ae. aegypti at 5 ug/mosquito and first instar larvae at 1 ug/ul. The major compound hexadecanoic acid showed 20% mortality at 6.25 ppm against adult Ae. aegypti whereas compound provided 100% mortality at the highest screening dose of 1000 ppm against 1st instar Ae. aegypti larvae. The mosquitocidal activity of R. ribes may be related to a specific combination of compounds present in the n-hexane extract.