Specific anosmia to 1-pyrroline: The spermous primary odor

About 20% of human subjects are specifically anosmic to the odor of the heterocyclic Schiff's base 1-pyrroline. Odor threshold measurements on 33 nitrogenous bases were made with panels of specific anosmics and normal observers. The anosmia proved to be very selective, and was encountered only with 1-pyrroline and its homolog 1-piperideine. The odor of 1-pyrroline resembles very closely that of human semen, and possibly represents a vestigial pheromone. It is suggested that this specific anosmia corresponds with the absence of a new olfactory primary, the “spermous” odor. The same odor occurs as an impurity in several organic reagents and can be detected in a variety of biological materials.     

Children's sensitivity to odor of trimethylamine

Findings in this paper show a strong correlation between subjects' age and their olfactory sensitivity to the fishy odor of trimethylamine, with youngest subjects being most sensitive and adult subjects least sensitive to this odor. This was due to a high percentage of highly sensitive subjects in the youngest age groups; this percentage decreased with age. Data further support the notion that trimethylamine sensitivity is independent of sex. The sensitivity to trimethylamine per se showed no significant covariations with the subjects' preferences for or aversions against fish as food and is probably of minor importance for fish food acceptability.     

Sensitivity of women to musk odor: No menstrual variation

It has been reported that the sensitivity of women to the musky odor of pentadecalactone exhibits cyclic variation,with a marked peak at about the time of ovulation. This claim was carefully reinvestigated, but was found to be untrue-in the conditions of our experiments. Possible reasons for the discrepancy are discussed.     

The perception of fragrance mixtures: A comparison of odor intensity models

A comparison of two psychophysical odor intensity models and their effect on the prediction of the odor character for perfume mixtures is presented. The odor value (OV) and Power‐Law models were applied together with previously developed perfumery ternary diagram (PTD®) and perfumery quaternary diagram (PQD) methodologies to map the perceived smell of quaternary and quinary fragrance mixtures. A diffusion model was used to simulate the evolution of liquid and headspace concentrations. The evaporation of perfumes starts with a fast ethanol release, then the diffusion of the fragrant components. The composition paths were predicted through the evaporation lines plotted in the PQD. The two odor intensity models present differences in the initial perfume impact, but after some time tend to similar profiles. The Power‐Law predicted higher ethanol intensities than the OV model, due to its exponent. Introducing water in perfume formulation fixes ethanol in the solution, thus reducing alcohol perception. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Selective Hydrogenation of Fatty Nitriles to Primary Fatty Amines: Catalyst Evaluation and Optimization Starting from Octanenitrile

In this contribution, an evaluation of the potential of various homogeneous and heterogeneous catalysts for a selective hydrogenation of fatty nitriles toward primary amines is reported exemplified for the conversion of octanenitrile into octane‐1‐amine as a model reaction. When using heterogeneous catalysts such as the ruthenium catalyst Ru/C, the palladium catalyst Pd/C, and the platinum catalyst Pt/Al₂O₃, low selectivities in the hydrogenation are observed, thus leading to a large portion of secondary and tertiary amine side‐products. For example, when using Ru/C as a heterogeneous catalyst, high conversions of up to 99% are obtained but the selectivity remains low with a percentage of the primary amine being at 60% at the highest. The study further reveals a high potential of homogeneous ruthenium and manganese catalysts. When also taking into account economical considerations with respect to the metal price, in particular, manganese catalysts turn out to be attractive for the desired transformation and their application in the model reaction leads to the desired primary amine product with excellent conversion, selectivity, and high yield. Practical Applications: This work describes an optimized hydrogenation process for transforming fatty nitriles to their corresponding primary amines. In general, fatty amines belong to the most applied fatty acid‐derived compounds in the chemical industry with an annual product volume exceeding 800 000 tons per year in 2011 and are widely required in the chemical industry since such compounds are either directly used in home products such as fabric softeners, dishwashing liquids, car wash detergents, or carpet cleaners or in a broad range of industrial products, for example, lubricating additives, flotation agents, dispersants, emulsifiers, corrosion inhibitors, fungicides, and bactericides, showing additional major applications, e.g., in the detergents industry. Among them primary amines play an important industrial role. However, a major concern of current processes is the lack of selectivity and the formation of secondary and tertiary amines as side‐products. By modifying a recently developed catalytic system based on manganese as economically attractive and environmentally benign metal component an efficient and selective access to fatty amines when starting from the corresponding nitriles is achieved. For example, hydrogenation of octanenitrile leads to a synthesis of octane‐1‐amine with >99% conversion and excellent selectivity with formation of secondary and tertiary amine side‐products being suppressed to an amount of <1%.     

Three-component reaction between elemental sulfur,primary phosphines,and amines: straightforward synthesis of organylammonium trithiophosphonates

Elemental sulfur reacts with primary phosphines and various amines in the 3:1:2 molar ratio under mild conditions (60°C, 10 min, ethanol) to afford hitherto unknown organylammonium trithiophosphonates in 84–91% yields.     

Attraction ofCeratitis capitata (Diptera: Tephritidae) flies to odor of coffee fruit

On potted nonfruiting host trees in outdoor field cages, we evaluated attraction of released mature laboratory-cultured or wild-origin Mediterranean fruit flies (medflies) to odor of freshly picked fruit of host and nonhost plants. Odor of ripe intact or crushed coffee fruit (the presumed ancestral host of medflies) was significantly more attractive than odor of ripe intact or crushed fruit of five lower-ranking hosts and three nonhosts. Odor of crushed coffee fruit was significantly more attractive than odor of intact coffee fruit. Odor of ripe or near-ripe coffee fruit was significantly more attractive than odor of unripe coffee fruit. Immature females (without eggs) were significantly more attracted to odor of a proteinaceous food lure than to odor of ripe coffee fruit, whereas the reverse was true for mature females carrying a high egg load. In some trials, males proved as discriminating as females in favor of coffee fruit odor, but in several other trials males were less discriminating than females. Response patterns of mature laboratory-cultured females were similar to those of mature wild-origin females. In a field of coffee plants, attraction of natural-population females was significantly greater to odor of ripe coffee fruit than to water but was not greater than attraction to odor of proteinaceous food. Findings are discussed in relation to potential use of synthetic volatiles of coffee or other host fruit in traps for monitoring or controlling medflies.     

Bioassay approaches to assessing behavioral responses of plum curculio adults (Coleoptera: Curculionidae) to host fruit odor

We evaluated several approaches to developing a simple, sensitive, and reliable laboratory bioassay of responses of overwintered adult plum curculios (PCs),Conotrachelus nenuphar (Herbst), to host fruit odor or its attractive components. A high proportion of assayed PCs responded positively to odor of wild plums under no-choice, moving-air conditions in a wind tunnel and under dual-choice, still-air conditions in enclosed Petri dishes. Positive response to controls lacking host odor, however, was much greater in the wind tunnel, arguing in favor of bioassays under dual-choice conditions in still air to provide greater PC discrimination. Response to host odor (from wild plums or hexane extract of wild plums or Liberty apples) in Petri dish bioassay chambers proved greatest: (1) during the scotophase of PCs under total dark or dim red light conditions, (2) when Petri dishes were completely enclosed, (3) when PCs were starved for 24 or 48 hr, and (4) when PCs were tested within seven weeks after apple tree petal fall. Neither the sex of a PC nor the direction in which a PC was obliged to move to find the source of host odor (upward through a port in the Petri dish lid or downward through a port in the base) had a substantial effect on level of response to host odor or discrimination of host odor from a nonodorous control. We conclude that an enclosed Petri dish bioassay chamber of the type described here should be a valuable asset in the process of chemically identifying components of host fruit odor attractive to PCs.     

Studies on the surface properties and the adhesion to metal of polyethylene coatings modified with primary aromatic amines

The surface free energy and acid–base characteristics of polyethylene coatings formed on steel in the presence of primary aromatic amines (PAAs) were investigated. PAAs were shown to interact with steel by a donor–acceptor mechanism. An increase in the coating adhesion is realized through chemical and physical bond formation between an adhesive and a substrate with the help of the PAA. The free surface energy of the contact‐to‐metal side of these coatings modified with PAA was shown to grow in parallel with the increase in adhesion. The results correlate with the data on polyethylene surface wetting with nonionic surfactants. Acid–base interactions were found to exert primary control over polyethylene's adhesion to steel. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 388–397, 2001     

The effect of short-range host odor stimuli on host fruit finding and feeding behavior of plum curculio adults (Coleoptera: Curculionidae)

In laboratory assays, we investigated responses of female plum curculios (PCs),Conotrachelus nenuphar (Herbst), to host and nonhost fruit or leaf odor when PCs were crawling on experimental tree branchlets or twigs. In choice tests where test specimens were hung from the ends of a wooden crosspiece, PCs made significantly more visits to host plum fruit than to plum leaves, nonhost tomato fruit, wax models of plum fruit, or blanks (wire). In similar tests, PCs made significantly more visits to plum leaves compared to nonhost maple leaves or to blanks. PCs in test chambers that contained host or nonhost odor were significantly more prone to feed on wax plum models in the presence of odor from host fruit or host leaves compared to odor from nonhost fruit or leaves or a water blank. In choice tests offering alternating cluster types on an apple branchlet, PCs visited leaf clusters bearing a host apple fruit more than leaf clusters without a fruit. In tests to assay the distance at which PCs can detect an individual host fruit, PCs crawled from the central stem of an apple branchlet onto a side stem significantly more often when an apple fruit on a side stem was hung 2 cm from the central stem compared to 4 or 8 cm away. Our combined results suggest that PCs use host fruit odor to locate host fruit at close range.     

In Situ Formed Bifunctional Primary Amine‐Imine Catalyst: Application to the Construction of Chiral Tertiary Alcohols through Asymmetric Aldol‐Type Reaction

An in situ formation method to obtain chiral bifunctional primary amine‐imine catalysts from the C₂‐symmetric chiral diimines has been developed. The efficiency of this method in the construction of chiral tertiary alcohols which are valuable pharmaceutical intermediates is proved by its application to the asymmetric aldol‐type reaction of cyclic ketones with other activated ketone compounds as the enamine acceptors, i.e., β,γ‐unsaturated α‐keto esters and isatins. In general, good to excellent diastereoselectivities and enantioselectivities (up to 96/4 dr, 96% ee for β,γ‐unsaturated α‐keto esters and up to 91/9 dr, 94% ee for isatins) were obtained. The active primary amine‐imine catalylst and enamine intermediate in the reaction process could be demonstrated by ESI‐MS analysis.     

The properties of multiple CMF determinations using alternative primary sets part I: Evidence and modeling

This article concerns William Thornton's single‐observer colour matching functions (CMFs). Alternative “prime colour” (or PC), “non‐prime” (or NP), and “anti‐prime” (or AP) wavelengths were used, and the measurements appear to challenge the basis on which conventional colorimetry predicts metameric colour matches. An analysis of Thornton's visual match data for alternative‐primary CMFs is presented. Using conventional colorimetric calculations, Thornton's articles establish failures of linear transformability between experimental data sets, failures of tristimulus sum prediction, and differences in CIE chromaticity for a set of strongly metameric stimuli that all match the same neutral reference stimulus. Error analysis using an optimization model is first used to confirm that Thornton's data represent a significant challenge to the standard colorimetric model. Thornton's assertion is supported that spectral power appears to be visually subadditive at NP and AP wavelengths compared with spectral power at the PC wavelengths. It is next shown that each of the individual failures of prediction can be eliminated by relatively minor adjustments to the relevant CMFs. However, each instance of failure required a different adjustment. Multiple and significantly incompatible linear adjustments of the CMFs are apparently needed to explain Thornton's results. The implication is that the visually additive value of the spectral stimuli used in the matches varies not only with wavelength but also as a nonlinear function of stimulus power. The implied variations in visual additivity become significant only at certain wavelengths. Thus a small and specific subset of strongly metameric light‐source matches, such as those chosen by Thornton, are required to reveal significant variations. Such spectrally localized variations have a minimal overall effect in the tristimulus sum predictions for surface‐colour matches using broadband stimuli. A detailed analysis of the central assumptions concerning additive colour mixing is given. It suggests that any super and subadditive visual effects revealed by Thornton's measurements can be accommodated within the standard colorimetric model by extending the model rather than by modifying the CMFs. An extension is proposed in which any possible super‐ or subadditive phenomena are modeled by a redefinition of the units of visual additivity, using a spectral‐level precursor transform. Its intent is to equate the additive properties of all possible incident stimuli numerically, prior to manipulation using the Standard Model. An appropriate methodology is also described for confirming measuring and classifying any spectrally distinct super and subadditive effects. Under The Heading for Prediction Failures the methods described are applied to Thornton's data. They reveal consistent evidence of additivity differences that are both wavelength and stimulus power dependent. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 273–284, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20022     

Two Be or Not Two Be: The Nuclear Autoantigen La/SS-B Is Able to Form Dimers and Oligomers in a Redox Dependent Manner

According to the literature, the autoantigen La is involved in Cap-independent translation. It was proposed that one prerequisite for this function is the formation of a protein dimer. However, structural analyses argue against La protein dimers. Noteworthy to mention, these structural analyses were performed under reducing conditions. Here we describe that La protein can undergo redox-dependent structural changes. The oxidized form of La protein can form dimers, oligomers and even polymers stabilized by disulfide bridges. The primary sequence of La protein contains three cysteine residues. Only after mutation of all three cysteine residues to alanine La protein becomes insensitive to oxidation, indicating that all three cysteines are involved in redox-dependent structural changes. Biophysical analyses of the secondary structure of La protein support the redox-dependent conformational changes. Moreover, we identified monoclonal anti-La antibodies (anti-La mAbs) that react with either the reduced or oxidized form of La protein. Differential reactivities to the reduced and oxidized form of La protein were also found in anti-La sera of autoimmune patients.