A status report on human odorant receptors and their allocated agonists.

Olfactory perception begins when odorous substances interact with specialized receptors located on the surface of dedicated sensory neurons. The recognition of smells depends on a complex mechanism involving a combination of interactions between an odorant and a set of odorant receptors (ORs), where molecules are recognized according to a combinatorial activation code of ORs. Although these interactions have been studied for decades, the rules governing this ligand recognition remain poorly understood, and the complete combinatorial code is only known for a handful of odorants.

Phytochemical study of Boswellia dalzielii oleo-gum resin and evaluation of its biological properties.

Boswellia dalzielii is a resin-producing tree endemic to West and Central Africa, used by local populations for various medicinal purposes. In this study, B. dalzielii gum resin was analyzed by GC-MS and UHPLC-MS to identify and quantify volatile and non-volatile compounds.

Construction of Chemical Libraries of Volatile Compounds by Combinatorial Synthesis of Homologous Mixtures: Alk-4-en-1-ols, Alk-4-enals and Methyl Alk-4-enoates.

A compound library of sixty six linear compounds, eleven representatives of six molecular families: (E)- and (Z)-isomers of alk-4-en-1-ols, alk-4-enals, and methyl alk-4-enoates, was prepared by combinatorial syntheses to allow the creation of a mass spectral database directly usable for their identification in GC/MS analyses. We demonstrate here that compound libraries can be prepared by combinatorial syntheses using long linear synthetic sequences, i. e.

(P. Beauv.): Investigation of the Chemical Variability and In Vitro Anti-inflammatory Activity of the Leaf Essential Oil from the Ivorian Species.

The variability of chemical composition of the leaf essential oil (EO) from , a climbing liana growing wild in Ivory Coast, was investigated for the first time. The in vitro anti-inflammatory activity was also evaluated. Thirty oil samples were isolated from leaves collected in three forests of the country and analyzed using a combination of Column Chromatography (CC), Gas Chromatography with Retention Indices (GC(FID)), Gas Chromatography-Mass Spectrometry (GC-MS), and Carbon-Nuclear Magnetic Resonance (C-NMR).

The Chemistry of Agarwood Odorants.

The phytochemistry of the fragrant infected heartwood of Aquilaria and Gyrinops species, agarwood (oud), is critically reviewed, highlighting the use of this remarkable natural raw material in perfumery. The chemistry of the two main groups of constituents of agarwood (sesquiterpenoids and chromones) is discussed, focusing particularly on the former structural type. The identities of the main key odorants of agarwood essential oil and of the smoke produced by heating the wood of agarwood are also discussed.

Blindness, But Not HMHA Anosmia, Predicts Loneliness: A Psychophysical Study.

Olfactory deficits can play a detrimental role in everyday social functioning. Perception of 3-hydroxy-3-methylhexanoic acid (HMHA)-a body odor component-could also be linked to this research area. However, no study so far has addressed the problem of HMHA perception in the context of the previously reported relationship between olfactory abilities and social difficulties.

Stereoselective synthesis of (6Z,8E)-undeca-6,8,10-trien-3-one (yuzunone) for its characterization in yuzu and various citrus essential oils.

(6Z,8E)-Undeca-6,8,10-trien-3-one (yuzunone) is reported to be one of the main olfactory contributors of the specific fruity-green-balsamic odor of yuzu peel oil. Using an original stereoselective synthesis, we prepared a pure sample of yuzunone, which was used as a reference compound to check its presence by GC-MS and GC-O in 5 commercial samples of yuzu and citrus essential oils. Surprisingly, we could not detect yuzunone by GC-MS in any of our samples.

Essential oils from leaves of (Spreng.) H. Rob.: chemical profile and antimollicute potential.

Aiming to valorise the Atlantic Rainforest biodiversity in Santa Catarina, the chemical characterisation of the essential oils (EOs) from leaves of (Spreng.) H. Rob.

Identification of key odorants in complex mixtures occurring in nature.

Covering: up to 2019Soon after the birth of gas chromatography, mass spectrometry and olfactometry were used as detectors, which allowed impressive development to be achieved in the area of odorant determinations. Since the mid-80s, structured methods of gas chromatography-olfactometry have appeared, allowing the determination of which odor constituents play a key role in materials. Progressively, numerous strategies have been proposed for sample preparation from raw materials, the representativeness evaluation of extracts, the identification of odor constituents, their quantification, and subsequently, the recombination of the key odorants to mimic the initial odor.

Interdisciplinary challenges for elucidating human olfactory attractiveness.

Many species use chemicals to communicate. In humans, there is increasing evidence that chemicals conveyed by the body are extremely important in interpersonal relationships. However, many aspects of chemical communication remain to be explored to fully understand this function in humans.

Analytical investigations on Boswellia occulta essential oils.

Three samples of Boswellia occulta gum resin (Grades I, II and III) were analyzed by GC-MS and GC-FID. Fifty constituents could be identified, and several of them were isolated by flash chromatography and characterized by NMR. The combinatorial synthesis of homologous series of reference constituents permitted the unambiguous identification of five 1-methoxyalkanes and one 1-methoxyalkene.

Prenylated β-diketones, two new additions to the family of biologically active Hypericum perforatum L. (Hypericaceae) secondary metabolites.

Two novel β-diketones, 2,6,9-trimethyl-8-decene-3,5-dione (A) and 3,7,10-trimethyl-9-undecene-4,6-dione (B), were identified from the renowned medicinal plant Hypericum perforatum L. The structures of β-diketones A and B were corroborated by syntheses (4 steps starting from methyl acetoacetate, overall yields 30% and 23%, respectively). In solution, these β-diketones predominantly exist as two rapidly interconverting β-keto-enol tautomers.

Odor-active constituents of Cedrus atlantica wood essential oil.

The main odorant constituents of Cedrus atlantica essential oil were characterized by GC-Olfactometry (GC-O), using the Aroma Extract Dilution Analysis (AEDA) methodology with 12 panelists. The two most potent odor-active constituents were vestitenone and 4-acetyl-1-methylcyclohexene. The identification of the odorants was realized by a detailed fractionation of the essential oil by liquid-liquid basic extraction, distillation and column chromatography, followed by the GC-MS and GC-O analyses of some fractions, and the synthesis of some non-commercial reference constituents.

The (+)-cis- and (+)-trans-Olibanic Acids: Key Odorants of Frankincense.

Frankincense (olibanum) is one of the oldest aromatic materials used by humans, but the key molecular constituents contributing to its characteristic odor remained unknown. Reported herein is the discovery that (1S,2S)-(+)-trans- and (1S,2R)-(+)-cis-2-octylcyclopropyl-1-carboxylic acids are highly potent and substantive odorants occurring in ppm amounts in all of the frankincense samples analyzed, even those showing radically different volatile compositions. These cyclopropyl-derived acids provide the very characteristic old churchlike endnote of the frankincense odor.

Direct immersion solid-phase microextraction with gas chromatography and mass spectrometry for the determination of specific biomarkers of human sweat in melted snow.

To provide a reliable tool for investigating diffusion processes of the specific components of the human odor 3-hydroxy-3-methylhexanoic acid and 3-methyl-3-sulfanylhexan-1-ol through the snowpack, we developed and optimized an analytical method based on direct immersion solid-phase microextraction followed by gas chromatography with mass spectrometry. Direct immersion solid-phase microextraction was performed using polyacrylate fibers placed in aqueous solutions containing 3-hydroxy-3-methylhexanoic acid and 3-methyl-3-sulfanylhexan-1-ol. After optimization, absorption times of 120 min provided a good balance to shorten the analysis time and to obtain suitable amounts of extractable analytes.

Multidimensional analysis of cannabis volatile constituents: identification of 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane as a volatile marker of hashish, the resin of Cannabis sativa L.

The volatile constituents of drug samples derived from Cannabis sativa L. were investigated by means of headspace solid phase microextraction (HS-SPME) and gas chromatography techniques (GC-MS, GC×GC-MS). Samples of cannabis herb and hashish showed clear differences in their volatile chemical profiles, mostly resulting from photo-oxidation processes occurring during the transformation of fresh cannabis herb into hashish.

Structure-odor relationships of semisynthetic β-santalol analogs.

A series of eleven β-santalol analogs, including nine new derivatives, was prepared by semisynthesis from natural (-)-(Z)-β-santalol and studied by gas chromatography-olfactometry (GC-O) to characterize their olfactory properties and potencies. These compounds and 45 others selected in the literature were used to build three olfactophores by molecular modelling. Three models were obtained that gather structural and physicochemical constraints that will be useful for further design of new sandalwood odorants.

Unravelling the scent of vetiver: identification of character-impact compounds.

Vetiver oil is a highly esteemed basic ingredient of modern perfumery, but the nature of the constituents that really impart its typical and most sought woody-earthy scent has remained controversial. Indeed, vetiver oil is considered as one of the most complex essential oils, being mostly composed of several hundreds of sesquiterpene derivatives with a large structural diversity. Its complexity has hindered the direct identification of its odoriferous components.

Activity of Ocimum basilicum, Ocimum canum, and Cymbopogon citratus essential oils against Plasmodium falciparum and mature-stage larvae of Anopheles funestus s.s.

The biological activities of essential oils from three plants grown in Cameroon: Ocimum basilicum, Ocimum canum, and Cymbopogon citratus were tested against Plasmodium falciparum and mature-stage larvae of Anopheles funestus. Gas chromatography and gas chromatography - mass spectrometry analyses showed that the main compounds are geranial, 1,8-cineole and linalool in C. citratus, O.

Anticancer activities of essential oils constituents and synergy with conventional therapies: a review.

Many studies have shown that a large number of terpenoids and aromatic compounds contained in essential oils have significant anticancer activities, both on cell lines and on tumors in animals. The activity of these constituents is related to the activation of cell death (apoptosis) induced by the caspases proteins in cancer cells, with minor modifications of healthy cells. Many phenomena seem to occur, among which are as follows: overexpression and regulation of liver detoxification enzymes, changes in the membrane potential of cancer cells and mitochondria, production of free radicals in cancer cells, inhibition of angiogenesis, and modification of tumor-inducing genes.

Qualitative and quantitative analysis of vetiver essential oils by comprehensive two-dimensional gas chromatography and comprehensive two-dimensional gas chromatography/mass spectrometry.

Vetiver essential oils (VEO) are important raw ingredients used in perfume industry, entering the formula of numerous modern fragrances. Vetiver oils are considered to be among the most complex essential oils, resulting most of the time in highly coeluted chromatograms whatever the analytical technique. In this context, conventional gas chromatography has failed to provide a routine tool for the accurate qualitative and quantitative analysis of their constituents.