Odor between

The difference m odor between (R) and (S) carvone results from their different behavior toward receptor sites m the nose It is believed that volatile molecules occupy only those odor receptors that have the proper shape to accommodate them Because the receptor sites are themselves chiral one enantiomer may fit one kind of receptor while the other enantiomer fits a different kind An analogy that can be drawn is to hands and gloves Your left hand and your right hand are enantiomers You can place your left hand into a left glove but not into a right one The receptor (the glove) can accommodate one enantiomer of a chiral object (your hand) but not the other... 

Dominance-related, in mice, rats, monkeys Maintenance or formation of social group Social cohesion and dispersion Signals (display, sounds, odor) between group members of different social rank, low-level/intensity of aggression... 

Often the difference in odor between two such forms is surprisingly great. For example, dextro carvone is the main odor constituent of caraway oil, while its optical isomer levo carvone is typical of spearmint. Among other materials that occur in important dextro and levo forms are citronellol and rose oxide. 

Sokolov, V. E., Kotenkova, E. V. Lyalyukhina, S. 1. 1985. Recognition by odor between closely related forms of the house mouse Mus musculus L.) and the mound- building mouse (Mus hortulanus Nordm.) possibility of information exchange. Izv. Acad. Nauk, ser. bioL, 1, 5—15 [translation from Russian, Consultants Bureau, Plenum publishing Corporation, New-York]. 

The odor threshold values were determined in aqueous solutions by a published method (12) using polyethylene bottles. The concentration was reduced by 2-fold dilutions, and the samples and a blank (water) were presented to the subjects. The threshold concentration was the lowest concentration at which more than 50% of the subjects could discriminate the odor between the sample being tested and the blank. The odor thresholds determined were (I) 40 ppb and (U) 3.5 ppb, as shown in Table III. The volatiles from the fruit obtained by steam distillation included I and n in concentrations of approximately 21 ppm and 840 ppm, respectively. Since each amount exceeded the threshold concentration by a large extent, it is clear that both of them significantly contributed to the smell of the fruit. 

Both esters have a sweet pungent odor and present a vapor inhalation ha2ard. They are rapidly absorbed through the skin and hydroly2ed to chloroacetic acid. The oral LD q for ethyl chloroacetate is between 50 and 100 mg/kg (52). 

The relationship between molecular stmcture and sensory properties is very unclear for compounds with odor. It seems likely that there is a set of odors that could be called primaries, but a widely accepted Hst of such primary odor quahties has not been devised. Molecular size and shape have been used to... 

Fig. 3. (a) Flame ionization detector (fid) response to an extract of commercially processed Valencia orange juice, (b) Gas chromatography—olfactometry (geo) chromatogram of the same extract. The abscissa in both chromatograms is a normal paraffin retention index scale ranging between hexane and octadecane (Kovats index). Dilution value in the geo is the -fold that the extract had to be diluted until odor was no longer detectable at each index. 

Whatever the physiology of odor perception may be, the sense of smell is keener than that of taste (22). If flavors are classed into odors and tastes as is common practice in science, it can be calculated that there are probably more than 10 possible sensations of odor and only a few, perhaps five, sensations of taste (13,21,35—37). Just as a hereditary or genetic factor may cause taste variations between individuals toward phenylthiourea, a similar factor may be in operation with odor. The odor of the steroid androsterone, found in many foods and human sweat, may eflcit different responses from different individuals. Some are very sensitive to it and find it unpleasant. To others, who are less sensitive to it, it has a musk or sandalwood-like smell. Approximately 50% of the adults tested cannot detect any odor even at extremely high concentrations. It is befleved that this abiUty is genetically determined (38). 

Difluoroethanol [359-13-7], F2CHCH2OH, is a colorless Hquid with an alcohol-like odor mp, 28.2°C, bp, 96°C d[, 1.3084 n], 1.3320 heat of combustion, —1026 kJ/mol(—245.3 kcal/mol). It is stable to distillation and miscible with water and many organic solvents. As expected, its acidity Hes between that of 2-fluoroethanol and 2,2,2-trifluoroethanol both ia the gas phase (25) and ia 50% aqueous ethanol solution (26), where its of 1.0 x 10 is about 4.8 times smaller than that of trifluoroethanol. 

Castor Oil. Castor oil [8001-79-4] (qv) is the fixed oil from the seeds of Picinus communis Linne. Pale yellowish or almost colorless, it is a transparent viscid Hquid with a faint, mild odor and a bland taste followed by a slightly acrid and usually nauseating taste. Its specific gravity is between 0.945 and 0.965. Castor oil is soluble in alcohol, and miscible with anhydrous alcohol, glacial acetic acid, chloroform, and diethyl ether. It consists chiefly of the glycerides of ricinoleic acid [141 -22-0], and isoricinoleic acid [73891-08-4], found in the small intestine. The seed contains a highly... 

On the other hand, intermediate paraffin distillates contain paraffin waxes and waxes intermediate in properties between paraffin and microwaxes. Thus, the solvent dewaxing process produces three different slack waxes depending on whether light, intermediate, or heavy paraffin distillate is processed. The slack wax from heavy paraffin distillate may be sold as dark raw wax, the wax from intermediate paraffin distillate as pale raw wax. The latter is treated with lye and clay to remove odor and improve color. 

At room temperature phenol is a white, crystalline mass. Phenol gradually turns pink if it contains impurities or is exposed to heat or light. It has a distinctive sweet, tarry odor, and burning taste. Phenol has limited solubiUty in water between 0 and 65°C. Above 65.3°C phenol and water are miscible in all proportions. It is very soluble in alcohol, ben2ene, chloroform, ether, and partially disassociated organics in general. It is less soluble in paraffinic hydrocarbons. The important physical properties of phenol are Hsted in Table 1. 

Denture Adhesives. Fast hydration and gel-forming properties are ideally mated to produce a thick, cushioning fluid between the dentures and gums (100). The biologically inert nature of poly(ethylene oxide) helps reduce unpleasant odors and taste in this type of personal-care product (see... 

In studies of the polymerization kinetics of triaUyl citrate [6299-73-6] the cyclization constant was found to be intermediate between that of diaUyl succinate and DAP (86). Copolymerization reactivity ratios with vinyl monomers have been reported (87). At 60°C with benzoyl peroxide as initiator, triaUyl citrate retards polymerization of styrene, acrylonitrile, vinyl choloride, and vinyl acetate. Properties of polyfunctional aUyl esters are given in Table 7 some of these esters have sharp odors and cause skin irritation. 

Physical properties of isopropyl alcohol are characteristic of polar compounds because of the presence of the polar hydroxyl, —OH, group. Isopropyl alcohol is completely miscible ia water and readily soluble ia a number of common organic solvents such as acids, esters, and ketones. It has solubiUty properties similar to those of ethyl alcohol (qv). There is a competition between these two products for many solvent appHcations. Isopropyl alcohol has a slight, pleasant odor resembling a mixture of ethyl alcohol and acetone, but unlike ethyl alcohol, isopropyl alcohol has a bitter, unpotable taste. 

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