Coactivity of sulfide ingredients: a new perspective of the larvicidal activity of garlic essential oil against mosquitoes.
BACKGROUND
The activity of several garlic oil ingredients against Culex pipiens L. larvae was studied. In addition to diallyl sulfide (DS) and diallyl disulfide (DDS), the garlic oils used included one essential oil (EO) and two semi-synthetic garlic essential oils (SSGEO1 and SSGEO2), which resulted from the enrichment of EO with DS and DDS standards respectively. The oils were compared with respect to their toxicity.


RESULTS
The chemical composition of the tested oils was evaluated by means of gas chromatography-mass spectrometry. Experimental data from the tested samples revealed high toxicity. In detail, DDS (6.09 mg L(-1)) was the most active, followed by SSGEO2 (7.05 mg L(-1)) and EO (8.01 mg L(-1)), while SSGEO1 and DS were relatively inactive.


CONCLUSIONS
The addition of DDS to EO did not change the toxic effect of the essential oil, whereas the presence of DS in excess produced an enriched essential oil with low toxicity. Furthermore, the antagonistic effect of DS and DDS against the other components of EO was shown by the application of two equations obtained from the literature. Their larvicidal performances were correlated, for the first time, with their detailed chemical composition. Data analysis strongly indicated the toxicity of the other EO sulfur ingredients.
Kimbaris
Athanasios C
AC
Faculty of Agricultural Development, Democritus University of Thrace, 193 Pantazidou Street, New Orestiada 68200, Greece.
Kioulos
Elias
E
Koliopoulos
George
G
Polissiou
Moschos G
MG
Michaelakis
Antonios
A
D000818:Animals; D003465:Culex / Q000187:drug effects* / Q000254:growth & development; D005260:Female; D005737:Garlic / Q000737:chemistry*; D007814:Larva / Q000187:drug effects; D008297:Male; D009822:Oils, Volatile / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013440:Sulfides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
D009822:Oils, Volatile; D013440:Sulfides