Structure-Activity Relationships in Odor Perception of Drimane Derivatives

The woody, ambergris-Iike odor of trans-decalone derivatives of type 5 increases with the introduction of equatorial alkyl substituents in the C(9)-positionand decreases drastically in the corresponding 9-epi derivatives. Complete stereocontrol of odor perception has been observed for the diastereoisomers of y-bicyclohomofarnesal 1 and 2. A similar tendency in odor perception has been recognized in substituted alcohols of type 12. The sandalwood- like ambergris note found in Polywood\u27": (14) disappeared in corresponding alkyl substituted acetates. The molecular basis of the \u27steroid-type\u27 scent of some esters of type 39 was hitherto unknown

Effect of Functional Group and Carbon Chain Length on the Odor Detection Threshold of Aliphatic Compounds

Odor detection thresholds (ODTs) are used for assessing outdoor and indoor air quality. They are obtained experimentally by olfactometry and psychophysical methods, and large compilations are available in the literature. A non-linear regression equation was fitted to describe the ODT variability of 114 aliphatic compounds based on the alkyl chain length for different homologous series (carboxylic acids, aldehydes, 2-ketones, esters, 1-alcohols, amines, thiols, thioethers and hydrocarbons). The resulting equation reveals an effect of the functional group, molecular size and also an interaction between both factors. Although the mechanistic interpretation of results is uncertain, the relatively high goodness-of-fit (R2 = 0.90) suggests that ODT values of aliphatic compounds can be predicted rather accurately, which is not the case for rigid molecules. This equation may serve as a basis for the development of more complex ODT models taking into account diverse structural features of odorants. The variability of power-law exponents was also investigated for the homologous series

Morphology of secretory structures and essential oil composition in Mentha cervina L. from Portugal

ABSTRACT: Mentha cervina L. is an aromatic plant that is traditionally used in the Alentejo region of Portugal to flavour food dishes and for the medicinal properties of the essential oil produced in its glandular trichomes. The morphology and distribution of the secretory structures of 20 populations was studied by light and scanning electron microscopy and revealed a great similarity in the type and distribution of glandular and non-glandular trichomes. In addition, two populations were surveyed at different stages of their life cycles. This showed that both maximum trichome density and maximum filling capacity of the glandular trichomes are attained early on. The GC and GC–MS chemical analyses showed that pulegone (62–80%), isomenthone (3–18%) and limonene (3–7%) are the main components of M. cervina essential oils. Cluster analysis of the identified essential oil components revealed a major chemical consistency between the 20 populations evaluate

Proposition of the 3-block perfume exhibition model: Using technology on turning visible and invisible reality such as perfumes

Perfumes are part of our daily life. They can be a possible way to express our beauty or they can bring to life some memories or they can be simply hygienical accessories. Hard to describe, impossible to see. Perfumes have some mystical aura above them. For the industry perspective, perfumes present a challenge that is how to turn visible such an invisible, intangible and mystical object. The lineup questions of this study seek to explore the artistic endeavor perfumes can display and the advantages of retrieving data to improve the exhibition and to develop new business models. To develop this theoretical, conceptual and exploratory study one must look at some of the scholars’ contributions to this subject and the fragrance exhibitions made to this day. Moreover, some empirical knowledge that helps to understand how value is perceived into modern perfumery is stated; such knowledge comes from previous exhibitions, either fragrance-related exhibitions or immersive experience exhibitions, and it can be studied and improved from one’s empirical experience. The study is aimed to serve as support for a Perfume Art Exhibitions and it will develop a role model for future olfactory art exhibitions. Sensorial experiences and the visitors’ embodiment are critical factors for the success of an exhibition; hence this article seeks to propose a new exhibition model, totally oriented for the visitors’ needs and expectations but also for the brands’ market research and segmentation efforts. The 3-block model can be used for both an exhibition and to a permanent art museum. This model is innovative because it enhances the artistic role of perfumes and it will get visitors to dive into perfumes, gaining vocabulary and exploring the “making of” perfumes.info:eu-repo/semantics/acceptedVersio

Cloning and functional characterization of carotenoid cleavage dioxygenase 4 genes

Although a number of plant carotenoid cleavage dioxygenase (CCD) genes have been functionally characterized in different plant species, little is known about the biochemical role and enzymatic activities of members of the subclass 4 (CCD4). To gain insight into their biological function, CCD4 genes were isolated from apple (Malus×domestica, MdCCD4), chrysanthemum (Chrysanthemum×morifolium, CmCCD4a), rose (Rosa×damascena, RdCCD4), and osmanthus (Osmanthus fragrans, OfCCD4), and were expressed, together with AtCCD4, in Escherichia coli. In vivo assays showed that CmCCD4a and MdCCD4 cleaved β-carotene well to yield β-ionone, while OfCCD4, RdCCD4, and AtCCD4 were almost inactive towards this substrate. No cleavage products were found for any of the five CCD4 genes when they were co-expressed in E. coli strains that accumulated cis-ζ-carotene and lycopene. In vitro assays, however, demonstrated the breakdown of 8′-apo-β-caroten-8′-al by AtCCD4 and RdCCD4 to β-ionone, while this apocarotenal was almost not degraded by OfCCD4, CmCCD4a, and MdCCD4. Sequence analysis of genomic clones of CCD4 genes revealed that RdCCD4, like AtCCD4, contains no intron, while MdCCD, OfCCD4, and CmCCD4a contain introns. These results indicate that plants produce at least two different forms of CCD4 proteins. Although CCD4 enzymes cleave their substrates at the same position (9,10 and 9′,10′), they might have different biochemical functions as they accept different (apo)-carotenoid substrates, show various expression patterns, and are genomically differently organized

Applications and Advances in Electronic-Nose Technologies

Electronic-nose devices have received considerable attention in the field of sensor technology during the past twenty years, largely due to the discovery of numerous applications derived from research in diverse fields of applied sciences. Recent applications of electronic nose technologies have come through advances in sensor design, material improvements, software innovations and progress in microcircuitry design and systems integration. The invention of many new e-nose sensor types and arrays, based on different detection principles and mechanisms, is closely correlated with the expansion of new applications. Electronic noses have provided a plethora of benefits to a variety of commercial industries, including the agricultural, biomedical, cosmetics, environmental, food, manufacturing, military, pharmaceutical, regulatory, and various scientific research fields. Advances have improved product attributes, uniformity, and consistency as a result of increases in quality control capabilities afforded by electronic-nose monitoring of all phases of industrial manufacturing processes. This paper is a review of the major electronic-nose technologies, developed since this specialized field was born and became prominent in the mid 1980s, and a summarization of some of the more important and useful applications that have been of greatest benefit to man

Use of Human Senses as Sensors

This paper is an overview of our recent findings obtained by the use of human senses as sensors, suggesting that human senses might be indispensable sensors, not only for practical uses but also for gaining a deeper understanding of humans. From this point of view, two kinds of studies, both based on semantic responses of participants, deserve emphasis. One study assessed the efficacy of the photocatalytic elimination of stains or bio-aerosols from an air environment using TiO2 as well as the photocatalytic deodorizing efficacy of a TiO2-type deodorizer; the other study evaluated the changes in perception of a given aroma while inhaling the fragrance of essential oils. In the latter study, we employed a sensory test for evaluating changes in perception of a given aroma. Sensory tests were conducted twice, when participants were undergoing the Kraepelin mental performance test (mental arithmetic) or an auditory task (listening to environmental natural sounds), once before the task (pre-task) and once after the task (post-task). The perception of fragrance was assessed by 13 contrasting pairs of adjectives as a function of the task assigned to participants. The obtained findings illustrate subtle nuances regarding how essential oils manifest their potency and how olfactory discrimination and responses occur in humans

Asymmetric Oxidative Cation/Olefin Cyclization of Polyenes: Evidence for Reversible Cascade Cyclization

Ag und Pt arbeiten zusammen: Die Aktivierung von [(xylyl-phanephos)PtCl2] durch Silber erzeugt einen elektrophilen Katalysator, der enantio-, diastereo- und regioselektiv die stereospezifische oxidative Cyclisierung von Polyenolen vermittelt (siehe Schema; Tr=Trityl). Mechanistische Experimente lassen darauf schließen, dass der konfigurationsbestimmende Schritt nicht die einleitende Cyclisierung ist, sondern ein Folgeschritt der Reaktion