Nicotine Carboxylate Insecticide Emulsions:  Effect of the Fatty Acid Chain Length

Abstract

The effect of fatty acid chain length on nicotine carboxylate insecticide emulsions has been studied in terms of particle size, interfacial tension, nicotine encapsulation on emulsion droplets, and bioactivity. The particle size of the nicotine emulsion and the interfacial tension at the nicotine carboxylate oil phase (0.03 M)--Tween 80 aqueous phase (0.001 M) were affected in a similar way by the change in the fatty acid chain length, which was correlated by the packing conformation of Tween 80 and nicotine carboxylate molecules as obtained by AM1 theoretical calculations. The amount of encapsulated nicotine inside the nicotine carboxylate emulsion droplets influenced the insecticide bioactivity of nicotine; this relationship was explained in terms of the acid value of the different fatty acids used to prepare the nicotine formulation.

Partition Coefficients of Alkaloids in Biphasic Ionic-Liquid-Aqueous Systems and their Dependence on the Hofmeister Series

“…1, were used to assess the potential of phosphonium-based ionic liquids as extractive phases for biomolecules. Both caffeine and nicotine are well known botanical insecticides (36)(37)(38). Nicotine, 1-methyl-2(3-pyridyl)pyrrolidine, is a major alkaloid found in tobacco plants.…”

“…Nicotine, 1-methyl-2(3-pyridyl)pyrrolidine, is a major alkaloid found in tobacco plants. However, the high nicotine mammalian toxicity (LD 50 ¼ 50 mg Á kg À1 ) has been a major drawback when considering the high risks involved during its extraction, handling, and application in the field (36). Still, nicotine mammalian toxicity could be reduced when formulated as emulsions, since emulsifiers and stabilizers that adsorb at the oil-water interface could act as shielding barriers (36).…”

“…However, the high nicotine mammalian toxicity (LD 50 ¼ 50 mg Á kg À1 ) has been a major drawback when considering the high risks involved during its extraction, handling, and application in the field (36). Still, nicotine mammalian toxicity could be reduced when formulated as emulsions, since emulsifiers and stabilizers that adsorb at the oil-water interface could act as shielding barriers (36). High-performance liquid chromatography (HPLC) (39)(40), capillary electrophoresis (41), and gas chromatography (GC) methods (42,43) have been reported for the analysis of nicotine and its metabolites in tobacco leaves.…”

Control of Green Peach Aphid (Myzus Persicae) by Combination of Plant Oil Formulations and Low-dosed Imidacloprid

“…Aphids would be covered with a thin film of oily materials such as fatty acids produced from plant oils. Botanical insecticides, such as nicotine from tobacco leaves, rotenone from derris tree roots, pyrethrum from chrysanthemum flowers and azadirachitin from neem tree have accepted as alternatives to conventional synthetic insecticides (Isman, 1997;Edelson, 2002;Casanova et al, 2005, Kim et al, 2007). The plant oil formulations can be also used in order to increase the insecticidal efficacy of botanical insecticides.…”

Rheology, microstructural characterization and physical stability of W/α-PINENE/W emulsions formulated with copolymers

“…Recently, in order to develop more ecofriendly and safer formulations, the replacement of traditional organic solvents (oil phase) by biodegradable solvents is increasingly promoted. In order to accomplish this goal, several authors have studied the applications of solvents obtained from renewable sources such as essential oils, which may be used as organic phase in simple and multiple emulsions [8][9][10][11][12][13]. An interesting essential oil for the formulation of agrochemical emulsions is -pinene, a terpenic solvent usually obtained from the pine bark or by distillation, which provides some activity as biobased pesticide [9,10,14].…”