Location: Subtropical Horticulture ResearchTitle: Insecticidal and biting deterrent activities of Magnolia grandiflora essential oils and selected pure compounds against Aedes aegypti
|ALI, ABBAS - University Of Mississippi|
|DEMIRCI, BETUL - Anadolu Universtiy|
|RAMAN, VIJAYASANKAR - University Of Mississippi|
|BUDEL, JANE - State University Of Ponta Grossa|
|BASER, K. HUSNU CAN - Near East University|
|KHAN, IKHLAS - University Of Mississippi|
Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2020
Publication Date: 3/17/2020
Citation: Ali, A., Tabanca, N., Demirci, B., Raman, V., Budel, J., Baser, K., Khan, I. 2020. Insecticidal and biting deterrent activities of Magnolia grandiflora essential oils and selected pure compounds against Aedes aegypti. Molecules. 25(6), 1359.
Interpretive Summary: This paper documents the investigation of essential oils of Magnolia grandiflora used commonly in American Indian Medicine as a bitter tonic and the treatment of malaria. Scientists at the USDA-ARS Subtropical Horticulture Research Station, University of Mississippi, Turkey, Cyprus, and Brazil collaborated to identify chemical constituents from different plant parts of Magnolia grandiflora and the insecticidal activity on the mosquito, Aedes aegypti. The essential oil of seeds was as effective as DEET. Compounds 1-decanol, 1-octanol, and 1-hectanol were present only in seed essential oil and 1-decanol demonstrated the highest mosquito biting deterrence, providing complete protection similar to DEET. Subsequently, 1-decanol was evaluated for larvicidal activity against Aedes aegypti and showed good larvicidal activity against this vector for the Zika virus. This is the first report on the mosquito repellency of M. grandiflora and validates the utilization of plant-derived essential oils as a biopesticide in insect-pest management.
Technical Abstract: In our natural products screening program for mosquitoes, we tested essential oils extracted from different plant parts of Magnolia grandiflora L. for their insecticidal and biting deterrent activities against Aedes aegypti. Biting deterrence of seeds essential oil with biting deterrence index value of 0.89 was similar to N,N-diethyl-3-methylbenzamide (DEET). All the other oils were active above the solvent control, but the activity was significantly lower than DEET. Based on GC-MS analysis, three pure compounds that were only present in the essential oil of seed were further investigated to identify the compounds responsible for biting deterrent activity. 1-Decanol with PNB value of 0.8 was similar to DEET (PNB = 0.8), whereas 1-octanol with PNB value of 0.64 showed biting deterrence lower than 1-decanol and DEET. The activity of 1-heptanol with PNB value of 0.36 was similar to the negative control. Since 1-decanol, which was 3.3% of the seed essential oil, showed biting deterrence similar to DEET as a pure compound, this compound might be responsible for the activity of this oil. In in vitro A & K bioassay, 1-decanol with MED value of 6.25 showed higher repellency than DEET (MED = 12.5). Essential oils of immature and mature fruit showed high toxicity whereas leaf, flower, and seeds essential oils gave only 20%, 0%, and 50% mortality, respectively, at the highest dose of 125 ppm. 1-Decanol with LC50 of 4.8 ppm was the most toxic compound.