Insect repellent activity

We also have studied insect repellent activity of some selected alkaloids (29 of them) against Tribolium casteneum adults [16], Table 4.1 shows the results, venu-luson (7) and hetisine (8) were found to be the most active alkaloids. 

Table 4.1 Insect repellent activity of some selected alkaloids...

Three plant growth promoters and five compounds with insecticidal or insect repellant activity have been identified from marine organisms. In addition, a number of extracts have been shown to be active in one or both of the assay systems. 

Table 3. The insect-repellent activity of aminoalkoxysilanes RlOCH t NCC ln against X. cheopis34 ...

Lukevics reports34 that silylation of 2-dibutylaminoethanol (2a) enhances its insect-repellent activity against X. cheopis (Table 3). For silyl derivative 2c the coefficient of repellent action reaches 99% at a dose of 5 g/m2. This effect is accompanied by prolongation of the repellent action. According to Lukevics, the activity of silyl derivatives 2b-2e cannot be explained by hydrolysis alone, because this process forms less active compounds. It appears that the repellent properties are concentrated within the molecule of the organosilicon compound itself. 

A variety of silylated alkylamines showing a wide diversity of biological activity have been studied. For example, a series of silylated amines is reported to have long-term insect-repellent activity (up to 30 days) compound 10 is typical of the group (53). Silylalkylamines having quaternary ammonium groups, such as 11, have been reported to have curare-like activity (54). 

More epoxides (1) with juvenile hormone activity (Vol. 2, p. 7) have been made by epoxidizing the Wittig products of citronellal (2), and some of these substances also increase silk production.Reduction of the double bond sometimes increases the activity against Oncopeltus fasciatus. Insecticidal activity is also reported for certain terpenoid cyclopropanes [e.g. (3), made from limonene and ethyl diazoacetate] and for isobornyl thiocyanoethyl ether (made from cam-phene and ethylene chlorohydrin followed by treatment with potassium thiocyanate). The insect-repelling activity shown by thujic acid amides (4) is... 

Diethyl ether extract of plant and nepeta-lactones have shown in vitro antibacterial and antifungal activities. ° Vapors of nepetalactone have shown repellent activity in 13 families of insects. The essential oil and the two isomers of nepetalactone have shown insect repellent activity to subterranean termites (Reticulitermes spp) and to male German cockroaches Blattella germanica) ,Z-nepe-talactone showed greater repellent activity than DEBT (A,V-diethyl-3-methylbenzamide). ... 

The 3D pharmacophore model for the insect-repellent activity of PMDs showed a good correlation (R = 0.9) with experimental data. 

A. K. Bhattachaijee, W. Dheranetra, D. A. Nichols, and R. K. Gupta, 3D pharmacophore model for insect repellent activity and discovery of new repellent candidates, QSAR Combinatorial Science, 24, 593-602, 2005. 

The catnip plant (Nepeta cataria) that provides cats with endless intrigue and entertainment has also been reputed to have insect-repelling activity (Table 5.1). In 1964, Thomas Eisner showed that several species of insects, including beetles, hemipterans, a caddisfly, and an ant, moved away from... 

G. E. Schultz, C. Peterson, and J. R. Coats, Natural insect repellents Activity against mosquitoes and cockroaches. In Natural Products for Pest Management, A. M. Rimando and S. O. Duke, eds., ACS, Washington, DC, pp. 168-181, 2006. 

S. Phasomkusolsil, M. Soonwera. Insect repellent activity of medicinal plant oils against Aedes aegypti (Linn.), Anopheles minimus (Theobald) and Culex quinquefasciatus (Say) based on protection time and biting rate. Southeast Asian J Trop Med Public Health, 41, 831, 2010. 

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