Volatile compounds, biological

Phosphorus also occurs in all living things and the phosphate cycle, including the massive use of phosphatic fertilizers, is of great current interest.O 20) -pj.jg movement of phosphorus through the environment differs from that of the other non-metals essential to life (H, C, N, O and S) because it has no volatile compounds that can circulate via the atmosphere. Instead, it circulates via two rapid biological... 

While the earlier studies in chemical ecology of mammals were preoccupied with relatively gross measurements (e.g., presence or absence of a chemi-cal/pheromone in an olfactory stimulus), the new quantitative capabilities make it now imperative to evaluate more accurately the volatile compound ratios or patterns under different biological circumstances. 

Zlatkis A, Kim K. 1976. Column elution and concentration of volatile compounds in biological fluids. 

Recalcitrant organic contaminants in the unsaturated zone, those that are difficult to remediate by vapor extraction, biodegradation, or other biological-chemical processes, can be removed via vitrification and electrical heating. This process involves heating the soil by electrical resistance or applied electrical fields to vaporize semi-volatile and volatile compounds, thermally to break down larger organic molecules, and (if heated sufficiently) to vitrify the mineral matter in the soil. 

Nezara antennata males produce similar volatile compounds, including Z-a-bisabolene, trans-Z-BAE, czs-Z-BAE, and E-nerolidol, as do males of four Acrosternum species [17,72]. In three of these species (A. aseadum, A. hilare, and A. marginatum), the transxis ratio strongly favors cz s-BAE, whereas in A. pennsylvanicum, the ratio is about equal. For all species except A. hilare, the absolute configurations of the compounds and their biological roles remain unknown. 

Abstract This chapter reviews chemical structures of biologically active, volatile compounds in beetles. Techniques used for structure elucidation are briefly discussed as well as facts and speculations on the biosynthesis of target compounds. Syntheses of selected substances are cursorily presented. The order of sections follows taxonomic classifications. Depending on the biological significance of relevant compounds in certain taxa, the corresponding sections are again subdivided into attractive compounds (mostly intraspecifically active pheromones) and defensive compounds (mostly interspecifically active allomones). 

Volatile compounds are often involved in long distance attraction and are especially important as attractants and repellents (as defined by Kogan, ). One major class of volatile materials, essential oils, is comprised of complex mixtures of terpenes, phenylpropanoid derived compounds and a number of esters, alcohols, aldehydes, ketones, acids, and hydrocarbons. The constituent compounds are mostly of low to medium molecular weight and generally not highly oxygenated. Some of the biological properties of these compounds have been reviewed (17,41,46,55,56). 

A number of sesquiterpenes have been demonstrated to have pronounced biological activity ( ) among the non-volatile compounds the sesquiterpene lactones are best known (M) but other oxygenated sesquiterpenes are also known to be active. For example, the role of gossypol, a dimeric sesquiterpene and structurally related compounds has been investigated (21,22). The oxygenated sesquiterpenes, shiromodiol monoacetate and diacetate, from Parabenzoin trilobum (=Lindera triloba Blume) possess potent anti feeding activity toward Spodoptera litura larvae (85). 

It is important to prevent the oxidation of edible fats and oils and of foods that contain oils to maintain their quality and safety. Oxidation of fats and oils can be initiated by heat, light, and metals in the fats and oils. The oxidation products from oils, which include hydroperoxides and cyclic peroxides, decompose to produce a variety of volatile compounds, which result in undesirable flavors and odors in oils (131-134). Oils damaged by oxidation also have been reported to cause biological problems, such as diarrhea, growth depression, and tissue damage in living organisms. 

Bartels-Hardege, H.D., Hardege, J.D., Zeeck, E., Muller, C., Wu, B.L., and Zhu, M.Y., Sex pheromones in marine polychaetes V a biologically active volatile compound from the coelomic fluid of a female Nereis (Neanthes) japonica (Annelida Polychaeta), J. Exp. Mar. Biol. Ecol., 201, 275, 1996. 

During the biological aging of sherry, the concentration of ethanol decreases because of its consumption by flor yeast. Its respiration via the tricarboxylic acid pathway (Suarez-Lepez and Inigo-Leal, 2004) provides the main source of carbon and energy. Acetaldehyde is the main organic byproduct of ethanol metabolism, but other volatile compounds, notably acetic acid, butanediol, diacetyl, and acetoin, can also be formed. In addition,... 

Peinado, R. A., Moreno, J. J., Ortega, J. M., and Mauricio, J. C. (2003). Effect of gluconic acid consumption during simulation of biological aging of sherry wines by a flor yeast strain on the final volatile compounds. ]. Agric. Food Chem. 51, 6198-6203. 

At that time the mass spectrometric ionization techniques of electron ionization (El) [1] and chemical ionization (Cl) [2] required the analyte molecules to be present in the gas phase and were thus suitable only for volatile compounds or for samples subjected to derivatization to make them volatile. Moreover, the field desorption (FD) ionization method [3], which allows the ionization of non-volatile molecules with masses up to 5000 Da, was a delicate technique that required an experienced operator [4], This limited considerably the field of application of mass spectrometry of large non-volatile biological molecules that are often thermolabile. 

Phytovolatilization involves the use of plants and plant-associated soil microbes to take up contaminants from the soil, transform them into volatile forms, and release them into the atmosphere (Lin, 2008). Phytovolatilization occurs as growing trees and other plants take up water and the organic and inorganic contaminants. Metalloids, such as selenium. As, and tin, can be methylated to volatile compounds or mercury that can be biologically transformed to elemental Hg. Phytovolatilization has been primarily used for the removal of mercury and selenium. 

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