Seoul National University · 農学・生物学
Professor Jun-Hyung Tak's research lab specializes in the discovery and mechanistic investigation of bioactive natural products, particularly plant-derived essential oils and their terpenoid constituents, for sustainable pest and vector control. The lab focuses on understanding the synergistic interactions between natural compounds, with an emphasis on pharmacokinetic mechanisms such as solubility, spreadability, and penetration enhancement in insect cuticles. Their work spans insecticidal, acaricidal, and fumigant activities against agricultural pests and disease vectors like mosquitoes, maize weevils, and mites, often combining chemical analysis with bioassay-driven compound identification. The lab also explores the potential of natural compounds as alternatives to synthetic pesticides, with a strong focus on structure-activity relationships and mode-of-action elucidation.
Figures are computed from collected data and may differ slightly.
Synergistic interactions between constituents of essential oils have been reported for several areas of research. In the present study, mechanisms that could explain the synergistic action of the two major insecticidal constituents of rosemary oil, 1,8-cineole and camphor against the cabbage looper, Trichoplusia ni were investigated. 1,8-Cineole was more toxic than camphor when applied topically to larvae, and when coadministered in their ratio naturally occurring in rosemary oil, the binary mix
Based on our results, the insecticidal activity of rosemary oil appears to be a consequence of the synergistic interaction between 1,8-cineole and (±)-camphor, and (±)-camphor should be considered a promising synergizing agent.
Abstract Many plant essential oils and their terpenoid constituents possess bioactivities including insecticidal activity, and they sometimes act synergistically when mixed. Although several hypotheses for this have been proposed, the underlying mechanism has not been fully elucidated thus far. In the present study, we report that in larvae of the cabbage looper, Trichoplusia ni , most synergistic or antagonistic insecticidal activities among mixtures of plant essential oil constituents are phar
Maize weevils, <i>Sitophilus zeamais</i>, are stored product pests mostly found in warm and humid regions around the globe. In the present study, acute toxicity via contact and residual bioassay and fumigant bioassay of 28 essential oils as well as their attraction-inhibitory activity against the adults of <i>S. zeamais</i> were evaluated. Chemical composition of the essential oils was analyzed by gas chromatography-mass spectrometry, and a compound elimination assay was conducted on the four mo
The acaricidal activities of paeonol (2'-hydroxy-4'-methoxyacetophenone) and benzoic acid identified in the root bark of tree peony, Paeonia suffruticosa Andrews, against copra mite, Tyrophagus putrescentiae (Schrank), adults were examined using direct contact and vapour phase toxicity bioassays and compared with those of cinnamyl acetate, cinnamyl alcohol and 37 monoterpenoids as well as the acaricides benzyl benzoate, dibutyl phthalate and N,N-diethyl-m-toluamide (DEET). Based on LD(50) values
Aedes aegypti L. (Diptera: Culicidae) is one of the most medically important mosquito species, due to its ability to spread viruses of yellow fever, dengue fever, and Zika in humans. In this study, the insecticidal activity of 17 plant essential oils was evaluated via topical application against two strains of Ae. aegypti mosquito, Orlando (insecticide-susceptible) and Puerto Rico (pyrethroid-resistant). Initial screens with the Orlando strain showed that cucumber seed oil (2017 sample) was the
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