Detection of the Previously Unobserved Stereoisomers of Thujone in the Essential Oil and Consumable Products of Sage (Salvia officinalis L.) Using Headspace Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry

Characterization of Odorants in a Commercial Culinary Sage (Salvia officinalis L.) and Several Cultivars

Culinary sage, Salvia officinalis L., is a popular spice plant commonly used throughout the world. In this study, 35 odorants were identified in dried sage via solvent-assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA), including 9 that were identified in sage for the first time. Fifteen odorants were quantitated by stable isotope dilution analysis (SIDA), and their odor activity values (OAVs) were determined. Odorants with high OAVs included (2E,6Z)-nona-2,6-dienal, 1,8-cineole, and β-myrcene. A formulated aroma simulation model closely matched the aroma profile of an aqueous infusion of dried sage. Enantiomeric proportions of selected odorants were determined by chiral gas chromatography. Furthermore, 6 different sage cultivars were grown in the greenhouse, dried under the same conditions, and analyzed. Sensory analysis determined that all cultivars were dominated by an herbaceous sensory attribute and had varying intensities of eucalyptus, mint, clove, pine, green, earthy, floral, and citrus notes. Cultivars with varying intensities of herbaceous, eucalyptus, pine, and green sensory notes correlated with the OAVs of α-thujone/β-thujone, 1,8-cineole, α-pinene, and (2E,6Z)-nona-2,6-dienal, respectively. This study identified the odorants driving the sensory profiles of different sage cultivars and serves as a foundation for future studies on the aroma chemistry of culinary sage.

Preparation of Chiral Enantioenriched Densely Substituted Cyclopropyl Azoles, Amines, and Ethers via Formal SN2′ Substitution of Bromocylopropanes

Enantiomerically enriched cyclopropyl ethers, amines, and cyclopropylazole derivatives possessing three stereogenic carbon atoms in a small cycle are obtained via the diastereoselective, formal nucleophilic substitution of chiral, non-racemic bromocyclopropanes. The key feature of this methodology is the utilization of the chiral center of the cyclopropene intermediate, which governs the configuration of the two adjacent stereocenters that are successively installed via 1,4-addition/epimerization sequence.

A three-step enantioselective synthesis of (+)- and (-)-α-thujone

The stereocontrolled three-step synthesis of either enantiomer of α-thujone from commercially available 3-methyl-1-butyne is described. The enantioselectivity originates from a Brown crotylation which is then conferred to the all-carbon quaternary center via chirality transfer in a gold-catalyzed cycloisomerization. The route is highly atom economical and requires no protecting groups or redox manipulations.

A GC-MS method validation for quantitative investigation of some chemical markers in Salvia hypargeia Fisch. & C.A. Mey. of Turkey: Enzyme inhibitory potential of ferruginol

In the present study, a GC-MS method used for quantitative screening of 26 compounds (sclareolide, sclareol, ferruginol, cryptanol, 6,7-dehydroroyleanone, suginal, 9,10-dihydro-7,8-dimethyl-2-(1-methylethyl) phenanthren-3-ol, sugiol, inuroyleanone, 12-demethylmulticauline, 7α-hydroxy-β-sitosterol, stigmasterol, sitosterol, salvigenin, sinensetin, α-amyrin, lupeol, lupenone, 3-acetyl lupeol, 1α,21α-dihydroxy-2,3-(1'1'-dimethyl-dioxymethylene) urs-9(11),12-dien, uvaol, betulin, pyxinol, lup-(20),29-ene-2α-hydroxy-3β-acetate, betulin 3β, 28β-diacetate, 21α-hydroxy,2α,3β-diacetoxy urs-9(11),12-dien) specific to Turkish Salvia species was developed and validated. According to the GC-MS analysis results, Salvia hypargeia Fisch. & C.A. Mey. roots were found to be rich in ferruginol (30787.97 µg/g extract) and lupenone (23276.21 µg/g extract), and leaves in lupeol (20625.92 µg/g extract). Additionally, the essential oil and aroma contents of this species were identified by GC-MS technique. According to the LC-MS/MS results, especially S. hypargeia leaf extract was rich in rosmarinic acid (38035.7 µg/g extract) and isoquercitrin (4136.91 µg/g extract). Furthermore, anticholinesterase, antiurease, antityrosinase and antielastase inhibitory, antioxidant, cytotoxic activities of the ethanol extracts, essential oil, and major components of the species were evaluated. Antioxidant potentials of all extracts of this species were quite high in all studied antioxidant methods. Moreover, butyrylcholinesterase and elastase inhibitory capacities of ferruginol, the major component of S. hypargeia roots, were notable. For these reasons, this species has a high potential for food and pharmaceutical industries. PRACTICAL APPLICATIONS: This new GC-MS method was applied to S. hypargeia Fisch. & C.A. Mey. and it indicated that this species possessed high amount of ferruginol and lupeol, and that this species could be used for their natural sources. According to the results of the activity studies (antioxidant, anticholinesterase, tyrosinase, elastase, and cytotoxic), this method was used to exhibit which compound may be responsible for the activities. This developed and validated method could be easily applied to determine major/active/toxic secondary metabolites of Salvia species which are used and/or could be used in pharmaceutical, cosmetic, and food industries.

When Gold Meets Perfumes: Synthesis of Olfactive Compounds via Gold-Catalyzed Cycloisomerization Reactions

An efficient, and mild synthetic route for the preparation of functionalized volatile oxa-bicyclo[4.1.0]-hept-4-ene (29 compounds, 44-98% isolated yields) has been developed relying on the association of IPrAuCl with NaBArF. The remarkable selectivity was demonstrated on a 1 g and 25 g scale with low catalyst loadings. The synthetic utility of these low-molecular-weight enols was further demonstrated by the derivatization of some adducts and by the unprecedented olfactory evaluation of all bicyclic derivatives.

Current Advances on the Extraction and Identification of Bioactive Components of Sage (Salvia spp.)

Common sage (Salvia spp., with the most common species Salvia officinalis L., Lamiaceae) is an important medicinal and aromatic plant, with antioxidant, antimicrobial, anti-inflammatory and anticancer properties. The polyphenolic compounds are mainly responsible for its diverse biological activity. Many different methods for extraction and identification of sage bioactive compounds, using various solvents, have been developed in recent years. The total phenolic content is usually measured and identified by various technical methodologies with different sensitivity and specificity. In this aspect, the present review is aimed to critically summarize and discuss various technical approaches for the extraction and identification of sage bioactive components in order to point out the more appropriate approaches of them.

Thymus mastichina L. essential oils from Murcia (Spain): Composition and antioxidant, antienzymatic and antimicrobial bioactivities

The compositions of essential oils (EOs) from Spanish marjoram (Thymus mastichina L.) grown in several bioclimatic zones of Murcia (SE Spain) were studied to determine their absolute and relative concentrations using gas chromatography-mass spectrometry. 1,8-Cineole and linalool were the main components, followed by α-pinene, β-pinene and α-terpineol. (-)-Linalool, (+)-α-terpineol and (+)-α-pinene were the most abundant enantiomers. When the antioxidant capacities of T. mastichina EOs and their compounds were measured by five methods, EOs and linalool, linalyl acetate, α-terpinene and γ-terpinene, among others, showed antioxidant activities. All four T. mastichina EOs inhibited both lipoxygenase and acetylcholinesterase activities, and they might be useful for further research into inflammatory and Alzheimer diseases. Bornyl acetate and limonene showed the highest lipoxygenase inhibition and 1,8-cineole was the best acetylcholinesterase inhibitor. Moreover, these EOs inhibited the growth of Escherichia coli, Staphylococcus aureus and Candida albicans due to the contribution of their individual compounds. The results underline the potential use of these EOs in manufactured products, such as foodstuff, cosmetics and pharmaceuticals.

Alkaloid profiling of herbal drugs using high resolution mass spectrometry

Herbal infusions are consumed worldwide thanks to their "natural" beneficial effects, also due to the presence of alkaloids, although these compounds can have poisonous effects. A method combining online solid-phase purification with high resolution mass spectrometry was used to define the alkaloid profiles of 117 herbs and 7 commercial blends. Forty-one alkaloids were quantified in reference to analytical standards, while the presence of a further 116 was confirmed based on accurate mass, retention time, and fragmentation profile. The targeted study showed that 52% of herbs and 42% of commercial blends contained at least one alkaloid. Pyrrolizidines were the most commonly present (26% of samples), with concentrations generally ranging from the quantification limit to roughly 100 μg kg^-1 . Moreover, a homemade infusion was studied, finding on average 45% and 6% lower extraction for pyrrolizidine and steroidal alkaloids, respectively. Nevertheless, the migration of pyrrolizidines was confirmed. The study confirmed the frequent presence, natural or accidental, of alkaloids in commercial infusion herbs, highlighting the urgent need for routine and accurate controls.

Salvia officinalis L. Essential Oils from Spain: Determination of Composition, Antioxidant Capacity, Antienzymatic, and Antimicrobial Bioactivities

Four essential oils (EOs) from Salvia officinalis L. cultivated in Spain (Murcia Province) were analyzed by gas chromatography coupled with mass spectrometry (GC/MS) to determine their relative and absolute compositions. The main components were α-thujone (22.8 - 41.7%), camphor (10.7 - 19.8%), 1,8-cineole (4.7 - 15.6%), and β-thujone (6.1 - 15.6%). Enantioselective gas chromatography identified (-)-α-thujone and (+)-camphor as the main enantiomers in all the analyzed EOs. Furthermore, when the EOs were tested to determine their antioxidant activity against free radicals and as ferric reducing and ferrous chelating agents, all were seen to have moderate activity due to the compounds they contained, such as linalool or terpinene. Because of their known relation with inflammatory illnesses and Alzheimer's disease, respectively, the inhibition of lipoxygenase and acetylcholinesterase was studied using the EOs. Some individual compounds also inhibited these enzymes. In addition, the studied EOs were able to inhibit the growth of Escherichia coli, Staphylococcus aureus, and Candida albicans. The characterization carried out increases our awareness of the possible uses of S. officinalis EO as natural additives in food, cosmetics, and pharmaceuticals.