Location: Mosquito and Fly Research
Title: Chemical constituents from Rheum ribes shoots and its insecticidal activity against Aedes aegyptiAuthor
DEMIRAY, HATICE - Ege University | |
Estep Iii, Alden | |
Tabanca, Nurhayat | |
BECNEL, JAMES - Retired ARS Employee | |
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. https://doi.org/10.1007/s43450-021-00224-8. DOI: https://doi.org/10.1007/s43450-021-00224-8 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. |