Hexanal Levels Research Articles

Nordihydroguaiaretic acid: inter- and intrapopulational variation in the sonoran desert creosote bush ( Larrea tridentata, zygophyllaceae.

Nordihydroguaiaretic acid (NDGA) is the principal phenolic constituent in the leaf resin of the creosote bush, Larrea tridentata, the dominant perennial shrub throughout most of the warmer arid and semi-arid regions of North America. In an effort to determine the quantitative significance of this biologically active lignan catechol in desert ecosystems, we conducted studies of leaf extracts from geographically distinct populations of Larrea which occur throughout the Sonoran desert. Seasonal influence on NDGA concentration as well as on the hexane- and MeOH-soluble leaf constituents were also examined within two populations of Larrea growing near Palm Desert, Califonia. Interpopulational studies revealed that NDGA concentrations declined from northern to southern sampling sites whereas the levels of hexane- or MeOH-soluble leaf components showed little variation. Intrapopulational studies showed that the mean level of both hexane- and MeOH-soluble leaf components increased significantly between mid-April and late June, but that these increases slowed down or stopped between June and July. The mean concentration of NDGA decreased significantly in plants between April and July suggesting a possible relationship between the resin concentration of NDGA and seasonal (i.e. climatic) changes. These observations may, in part, explain some of the latitudinal variation in NDGA levels found in Sonoran desert representatives of Larrea.

Volatiles in Skin of Low Dose Irradiated Fresh Chicken

ABSTRACTFresh chickens were irradiated with up to 1200 krad at 0–5°C. Volatile compounds from the skin and subcutaneous fat of these chickens, and from unirradiated controls, were analyzed by gas chromatography. Acceptability of the odor of the chickens was also evaluated. Other samples (0 and 300 krad) were evaluated by chemical and sensory analysis after storage at 4°C. Analysis of volatiles indicated that levels of octane, l‐octene, hexanal, and nonane increased regularly with radiation dose. Amount of total volatiles was greater in unstored irradiated samples than in controls, but this was reversed after storage. After 14 days, the irradiated sample still had acceptable odor, while the control ahd severely deteriorated.

Copulatory Behavior of Spruce Budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae): Experimental Analysis of the Role of the Sex Pheromone and Associated Stimuli

Pheromone-stimulated spruce budworm, Choristoneura fumiferana (Clemens), males do not attempt copulation unless an appropriate releaser stimulus is associated with the pheromone source. Thus, no copulation attempts were observed when synthetic pheromone (95:5:2 ratio of E/Z -11-tetradecenal and tetradecanal) or pheromone extracts were released from a flat filter paper substrate, but males readily attempted to copulate with pheromone-treated rubber septa or untreated septa adjacent to a pheromone source. Septa spatially separated from the pheromone source were ineffective. Orientation of pheromone-treated septa affected copulatory behavior: horizontal septa were significantly better releasers than vertical septa presumably because they provided more effective tactile stimulation. Presence of tetradecanal in the pheromone blend decreased the latency of the male's copulatory response to these septa and increased the frequency of his copulatory attempts. Conspecific scales from either sex applied to untreated septa or the filter paper substrate released copulatory behavior from pheromone-stimulated males, but pulverized scales and scale extracts did not. The essential cue evoking copulation is associated with mechanical properties of the scales. Rubber septa without pheromone but emitting relatively high levels of hexane or ethanol evoked copulatory behavior from pheromone-stimulated males. These chemicals may act as novel, nonspecific releaser stimuli.

Hexane losses in solvent extracted soya meal: Measurement by gas chromatography and brief evaluation

AbstractHexane losses in solvent extraction plants arise from a variety of causes. With the constantly increasing price of hexane, it has become imperative to identify the major loss areas and quantify losses in these areas. Hexane lost in meal leaving the desolventizer‐toaster (D‐T) is an obvious choice for investigation. A method has been developed for determining relatively high levels of hexane in hot meal leaving the D‐T. The method was designed to minimize the loss of solvent by cvaporation between the time of sampling and the actual measurement by gas chromatography (GC) Examination of the reults confirmed that losses of hexane as a result of inadequate stripping of the meal in the D‐T formed a very significant part (10–40%) of total hexane losses.

2706. Tissue levels of hexane following inhalation: Böhlen, P., Schlunegger, U. P. & Läuppi, E. (1973). Uptake and distribution of hexane in rat tissues. Toxic. appl. Pharmac.25, 242

2706. Tissue levels of hexane following inhalation: Böhlen, P., Schlunegger, U. P. & Läuppi, E. (1973). Uptake and distribution of hexane in rat tissues. Toxic. appl. Pharmac.25, 242