Glucosinolate from leaf of Solanum nigrum L. (Solanaceae) as a new mosquito larvicide

The present study was carried out to investigate the biocontrol potentiality of active ingredient isolated from ethyl acetate extract of mature leaves of Solanum nigrum L. (Solanaceae) against the larval form of Culex quinquefasciatus Say. Mortality rate at a concentration of 25 mg/L of the active compound was highest (P < 0.05) amongst all tested concentrations. Result of log-probit analysis (at 95% confidence level) revealed that LC₅₀ and LC₉₀ values are inversely proportional to exposure period of bioassay. A clear dose-dependent mortality was observed, as the rate of mortality (Y) was positively correlated with the concentrations of the compound (X); having regression coefficient value close to 1. The compound was found to be ecofriendly as it did not show any adverse effect to the studied nontarget organisms. Chemical characterization of the active ingredient was also carried out by infrared spectroscopic analysis (IR), mass analyses (GC-MS) and carbon-hydrogen-nitrogen-sulphur analyses (CHNS), that revealed the presence of a glucosinolate compound [1-thio-ß-D-glucopyranose-1-[(R)-3-hydroxy-2-ethyl-N-hydroxysulfonyloxy propanimidate] having the molecular formula of C₁₁H₂₁NO₁₀S₂.