Repellant activity

More recendy the cis and trans isomers of the mosquito repellent CIC-4, a mixture of citroneUa isomers, have been separated by preparative hplc and bioassayed for effectiveness (23). Chiral-phase capillary gas chromatography and mosquito repellent activity of some oxazoUdine derivatives of (+)-and ( —)-citroneUal have been studied to find stmcture—activity relationships (24). Several 2-aLkyl- -acetyloxahdines have been synthesized and tested against mosquitoes, with further efforts using nmr to determine the rotational isomers of the more active N-acetyl-2,2-dimethyloxazohdine (25). 

A similar paper emanator impregnated with 200 mg of Metofluthrin exhibited almost complete repellent activity against A. albopictus in Japan [3]. 

In Washington State and Florida State in the USA, this emanator showed excellent repellent activity against Aedes vexans and Ochlerotatus taeniorhynchus, respectively [8]. 

Boyd KG, Adams DR, Burgess JG (1999) Antibacterial and repellent activities of marine bacteria associated with algal surfaces. Biofouling 14 227-236 Cebrian J, Enriquez S, Fortes M, AgawinN, Vermaat JE, Duarte CM (1999) Epiphyte accrual on Posidonia oceanica (L.) Delile leaves implications for light absorption. Bot Mar 42 123-128... 

On the other hand, the defensive secretions of Sipyloidea sipylus and of Megacrania tsudai, two phasmid insects originating from Asia, contain volatile compounds, and, in both cases, the whole secretion has a repellent activity [180,181]. 

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. 

Repellent activity. The lotions and creams containing coconut oil were efficient in protecting against Simulium damnosum bites . 

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). 

Repellent activity was detected in ethers containing pyrrolidine ring in the radical [222, 223], During initial trials N-pyrrolidylglycolphosphorous acids exhibited weak antifungal activity against dermatophytes and insecticidal and fungicidal activity. 

Clove oil exhibits repellent activity on Anopheles albimanus, Aedes aegypti, A. dims and Culex quinquefasciatus (Barnard, 1999 Trongtokit et al., 2005). 

Erler, F., Ulug, I. and Yalcinkaya, B. (2006) Repellent activity of five essential oils against Culex pipiens. Fitoterapia 77(7-8), 491-494. 

Repellent activity, which also respected as insecticidal activity, of T. vulgare was reported by Schearer [222]. The steam distillate of fresh leaves and flowers of tansy was found to be strongly repellent to Colorado potato beetles, Leptinotarsa decemlineata. It seems that this activity is related with essential oils. 

Repellence tests with essential oils at 90% concentration indicated that five essential oils were effective repelling mosquitoes for 90 min (Table III). The essential oil of Acantholippia seriphioides was repellent even at the lowest concentration tested (12.5%). Repellence by this essential oil was expected because its main components are p-cymene (53%) and thymol (47%), both components showed repellent activity for approximately Ih against mosquitoes species (46). At concentrations of 12.5%, Aloysia citriodora, Baccharis spartioides and Rosmarinus officinalis showed the longest repellency times. Comparisons of the principal components of each essential oil suggest that limonene and camphor were the main components responsible for the repellent effects (46). 

In 1995 Watanabe et ol. at Sumitomo Chemical Co. isolated and identified a degraded monoterpenoid (+)-rotundial (68, Figure 3.17) as a new mosquito repellent from Vitex rotundifolia, a medicinal plant whose leaves and twigs were used for repelling mosquitoes. They reported that the mosquito-repelling activity... 

Ant venoms from the genus Solenopsis have provided an array of 2,6-disubstituted piperidines, including 197-206. A review of the fungicidal, insecticidal and repellent activity of these alkaloids has appeared [476]. Both solenopsin A (198a) and isosolenopsin A (200) were potent inhibitors (Ki = 0.16 pM and 0.24 pM, respectively) of [ HJ-perhydrohistrionicotoxin binding to sites associated with the nicotinic receptor-gated ion channel in the Torpedo califomica electric organ [477]. 

The topical mosquito-repellent activity of a range of simple quinoxaline derivatives, including 6-chloro- and 6-methoxyquinoxalines, has been tested, but none of the compounds tested was superior to diethyl-toluamide7 ... 

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