Long-Chain Methyl-Branched Hydrocarbons: Occurrence, Biosynthesis, and Function

Cuticular Hydrocarbons as Chemotaxonomic Characters for Nasutitermes corniger (Motschulsky) and N. ephratae (Holmgren) (Isoptera: Termitidae)1

“…They also gave EI and CI mass spectra identical to those of standard n-alkanes. Branched alkanes were readily identified from their CI-MS determined carbon numbers (Howard et al 1980b), their equivalent chain lengths (Jackson & Blomquist 1976), and their characteristic EI-MS fragmentation patterns (Jackson & Blomquist 1976, Nelson 1978. The single alkene present was characterized as its dithiomethyl ether derivative (Francis & Veland 1981).…”

Comparative Toxicity of Selected Aviation Fuels as Measured by Insect Bioassay

“…The reduced susceptibility to the jet fuel of flour beetles versus rice weevils could be explained by the greater variety and amount of certain hydrocarbons present in flour beetles. Flour beetles contain hydrocarbons which function as sex pheromones and also contain a significant amount of 1-pentadecene which functions as a surfactant facilitating the absorption of defensive quinones by predators (Nelson, 1978). An experiment was performed in which ether extractions of whole insect cuticles were separated by thin layer chromatography (TLC) using silica gel and a solvent system of petroleum ether and diethyl ether (95:5).…”

A Novel Synthesis of Branched High-molecular-weight (C40+) Long-chain Alkanes

“…methylated) alkanes are widely distributed in the natural environment, occurring in extremeophillic bacteria, certain algae, many terrestrial plants and animals, and in geological deposits ranging in age from recent to the Proterozoic period. [1][2][3] The higher-molecular-weight members (containing greater than 40 carbon atoms, i.e. C40 + ) of this class of alkanes are important components of the surface waxes of insects and the higher-molecular-weight fractions of petroleum.…”

“…C40 + ) of this class of alkanes are important components of the surface waxes of insects and the higher-molecular-weight fractions of petroleum. [3][4][5][6] Many questions remain concerning the chemical structures, biological functions and physical and chemical properties of these C40 + long-chain alkanes. Terrestrial organisms use these higher-molecularweight alkanes as cuticular waxes to regulate the uptake and loss of water, act as a barrier against microorganisms, prevent the penetration of inorganic chemicals, aŠect the absorption of agricultural chemicals, and play a role in chemosensory communication.…”

“…3) Long-chain alkanes with internal alkyl modiˆca-tion are components of petroleum microcrystalline waxes and are associated with the organic scale that causes oil-ˆeld production problems involving the fouling of wells, pipelines, and petroleum reservoirs. [4][5][6] The carbon number predominance patterns of these higher alkanes can also provide geological information on the source rock paleodepositional environment that is useful in petroleum exploration.…”