Location: Mosquito and Fly ResearchTitle: Chemical composition of the essential oil and n-hexane extract of Stachys tmolea subsp. tmolea Boiss., an endemic species of Turkey, and their mosquitocidal activity against dengue vector Aedes aegypti
|DEMIRAY, HATICE - Ege University|
|ESTEP, ALDEN - Navy Entomology Center Of Excellence, Cmave Detachment|
|DERMIRCI, BETÜL - Anadolu Universtiy|
Submitted to: Saudi Pharmaceutical Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2019
Publication Date: 5/24/2019
Citation: Demiray, H., Tabanca, N., Estep, A.S., Becnel, J.J., Dermirci, B. 2019. Chemical composition of the essential oil and n-hexane extract of Stachys tmolea subsp. tmolea Boiss., an endemic species of Turkey, and their mosquitocidal activity against dengue vector Aedes aegypti. Saudi Pharmaceutical Journal. 27(2019) 877–881. https://doi.org/10.1016/j.jsps.2019.05.009.
Interpretive Summary: Mosquito-borne diseases are a global problem and a continued threat to public health. Emergence of resistance to the majority of existing compounds has prompted a continued demand for new insecticides. In the current study, we examined the chemical compositions of the essential oil and n-hexane extract, obtained from aerial parts of Stachys tmolea, and evaluated the insecticidal activity against the dengue vector Ae. aegypti. The n-hexane extract produced 90% mortality whereas the essential oil showed only 13% mortality against adult Ae. aegypti. Further studies are planned on the extract to identify the compounds responsible for the activity against adult Ae. aegypti.
Technical Abstract: Stachys tmolea subsp. tmolea Boiss. is endemic to Turkey and is a species of the genus Stachys L. which is one of the largest genera of the family Lamiaceae with about 300 species. The aims of this study were to examine the chemical composition of the essential oil and n-hexane extract of S. tmolea subsp. tmolea as a natural sources of insecticidal activity against the dengue vector, Aedes aegypti. Analysis of the essential oil by GC-FID and gas chromatography-mass spectrometry (GC-MS) systems identified hexahydrofarnesyl acetone (15%), viridiflorol (10%), hexadecanoic acid (7%) and 9-geranyl-p-cymene (6%) as major components. The volatile components of the n-hexane extract were extracted using headspace solid-phase microextraction (HS-SPME) and were analyzed using GC-MS. The principal constituents were 3,4-dimethyl decane (16%), 3-methyl-3-pentanol (15%), 2-methyl-2-pentanol (12%), 1,4-bis (1,1-dimethylethyl) benzene (12%), heptanal (10%), acetic acid (6%) and decane (4%). Bioassay of the hexane extract, at 5 µg/mosquito, produced 90% mortality against adult Ae. aegypti while the S. tmolea essential oil demonstrated 13% mortality. No larvicidal activity was observed. Further studies are needed to assess the adulticidal activity of the responsible compounds in the crude extract.