Chemical Composition of the Essential Oil of Ocimum tenuiflorum and its Mosquito Larvicidal and Repellency Effects 

Author

NOR AZAH M.A., ZARIDAH M.Z. , ABDUL MAJID J. , ABU SAID A. , MOHD. FARIDZ Z. , SOLHAN Y. & NOR HADIANI I. , MOHD NOH J.

Proceeding

The 21st Annual Seminar of the Malaysian Natural Product Society.(Herbal Medicine:Natural Products S ciety), Palm Garden, Putrajaya Malaysia.

Date

22/11/2005

Keyword

Ocimum tenuiflorum, essential oil, chemical composition, larvicidal, repellency, Aedes aegypti, Culex quinquefasciatus

Abstract

The essential oil of the fresh aerial parts of Ocimum tenuiflorum, obtained by hydrodistillation, was analysed by a combination of capillary GC and GC-MS.  The most abundant component of the oil was methyl eugenol (68.7%). Other compounds that were present in appreciable amounts were β-caryophyllene (11.6%), α-cubebene (5.6%), methyl isoeugenol (3.8%), eugenol (2.1%) and endo-borneol (1.7%).  The oil was assessed for its larvicidal and repellent effects against Aedes aegypti and Culex quinquefasciatus. The mosquito larvicidal assay was carried out according to the WHO method while the repellency assessments was performed using the test cage as described in the American Society for Testing and Materials (ASTM) Standard E951-83.  Results indicated that the late 3rd  instar larvae of Cx. quinquefasciatus  (LC50   31.34 ppm) were more susceptible to the essential oil than Ae. aegypti (LC50  44.32 ppm). However, the oil showed repellency effect  against Ae. Aegypti ( EC50 0.0235 mg/cm2 ) but was inactive against Cx. quinquefasciatus.