Nonacosane

Abstract: We previously described methods for age-grading female Aedes aegypti (L.) by gas chromatographic (GC) analysis of whole-body cuticular hydrocarbon patterns. Two regression models were developed that were based on the age-dependent, relative abundance of 2 cuticular hydrocarbons, pentacosane (GC peak 1) and nonacosane (GC peak 5). We have refined this method so that only the legs are required to age individual females. Two new regression models were developed that also use the relative abundance of a 3rd cuticular hydrocarbon, octacosane (GC peak 4). These models improve the overall accuracy of the cuticular hydrocarbon method for aging female mosquitoes, especially for older females from 132 to 165 degree-days (DD) of age (12-15 calendar days at 28 degrees C). The correlation coefficients (R2) for the best-fitted linear regression models for aging females from 0 to 132 and 0-165 DD were 0.80 and 0.81, respectively (P < 0.001 in all cases). The use of leg cuticular hydrocarbons for estimating the age of female Ae. aegypti has a significant advantage over whole-body extracts as indicated by the decreased variability associated with the relative abundance of pentacosane and the expanded range over which the models were able to predict age accurately by the addition of the relative abundance of octacosane.

Abstract: According to distribution of genus Achillea, two main centers of diversity occur in S.E. Europe and S.W. Asia. Diversified essential oil compositions from Balkan Peninsula have been numerously reported. However, report on essential oils of Achillea species growing in Turkey, which is one of the main centers of diversity, is very limited. This paper represents the chemical compositions of the essential oils obtained by hydrodistillation from the aerial parts of eleven Achillea species, identified simultaneously by gas chromatography and gas chromatography-mass spectrometry. The main components were found to be 1,8-cineole, p-cymene, viridiflorol, nonacosane, α-bisabolol, caryophyllene oxide, α-bisabolon oxide A, β-eudesmol, 15-hexadecanolide and camphor. The chemical principal component analysis based on thirty compounds identified three species groups and a subgroup, where each group constituted a chemotype. This is the first report on the chemical composition of A. hamzaoglui essential oil; as well as the antioxidant and antimicrobial evaluation of its essential oil and methanolic extract.

Abstract: Components of a sex pheromone that cause male face flies to strike at females were found to be the straight-chain monoalkenes (Z)-14-nonacosene, (Z)-13-nonacosene, and (Z)-13-heptacosene. Although these compounds were found in the extracts of both sexes, extracts from sexually mature males contained a much higher proportion of nonacosane and heptacosane, which attenuated the activity of the active monoalkenes. The monoalkenes were readily synthesized by a Wittig reaction modified by the use of hexamethylphosphoric triamide as a cosolvent with tetrahydrofuran to produce a product containing 94–96% (Z) isomer.