Make the Quality Control of Essential Oils Greener: Fast Enantioselective GC-MS Analysis of Sweet and Bitter Orange as a Case Study.

Quality control of essential oils is fundamental for verifying their authenticity and conformity with quality standards, ensuring their safety and regulatory compliance, and monitoring their consistency. Companies that produce or market essential oils routinely evaluate the quality and authenticity of their products. However, they also must deal with increasing attention to environmental sustainability as well as practical considerations such as productivity, cost, and simplicity of methods. In this study, enantioselective gas chromatography (GC) was adopted to evaluate the quality of sweet and bitter orange essential oils, used as a case study. The analytical conditions were optimized and translated to fast GC to evaluate the impact of this approach on the environmental footprint of the analyses. The greenness of fast GC, compared with conventional GC, was quantitatively evaluated using a dedicated metric tool (AGREE), and important improvements have been calculated. The developed methods were applied to a set of commercial essential oils, and the data about the enantiomeric composition and relative percentage abundance were elaborated through multivariate statistics (principal component analysis). The results showed that fast chiral gas chromatography enables the classification of citrus essential oil samples and can be considered an environmentally friendly and sustainable approach for evaluating their quality.

Chemical Profiles and Cytotoxic Activities of Essential Oils from Six Species of Baccharis Subgenus Coridifoliae (Asteraceae).

Several Baccharis species are popularly known in traditional medicine as "carquejas", "vassouras", "ervas-santas" and "mio-mios", and are used as anti-inflammatories, digestives, and diuretics. This study aimed to investigate the chemical compositions and cytotoxic activities of essential oils (EOs) of six Baccharis species belonging to subgenus Coridifoliae, namely B. albilanosa, B. coridifolia, B. erigeroides, B. napaea, B. ochracea, and B. pluricapitulata. GC/MS analyses of the EOs showed that the oxygenated sesquiterpenes spathulenol (7.32-38.22 %) and caryophyllene oxide (10.83-16.75 %) were the major components for all the species. The EOs of almost all species were cytotoxic against cancer (BT-549, KB, SK-MEL and SK-OV-3) and normal kidney (VERO and LLC-PK1) cell lines, whereas B. erigeroides EO showed cytotoxicity only against LLC-PK1. This article augments the current knowledge about the chemical-biological properties of Baccharis subgenus Coridifoliae and discusses the therapeutic potentials of these economically unexploited plants.

Relationship between Baccharis dracunculifolia DC. and B. microdonta DC. (Asteraceae) by Their Different Seasonal Volatile Expression.

Baccharis dracunculifolia DC. and Baccharis microdonta DC. (Asteraceae) are woody species morphologically similar growing in Uruguay, where not taxonomists people often confuse them in field conditions. As the essential oil of B. dracunculifolia ('vassoura' oil) is highly prized by the flavor and fragrance industry, the correct differentiation of the two species is a key factor in exploiting them profitably and reasonably. To differentiate both Baccharis species, in this work their volatile expression profiles were studied as an alternative tool to determine authenticity and quality. Volatile organic compounds (VOCs) were monthly extracted during an entire year from aerial parts of wild populations by simultaneous distillation extraction (SDE), and studied by gas chromatography/mass spectrometry (GC/MS; identification) and conventional gas chromatography (GC-FID; component abundances determination). Enantioselective gas chromatography/mass spectrometry (Es-GC/MS) was applied in the search of parameters able to ensure genuineness of each species extract. Qualitative VOCs profiles were found to be similar for both species, being ß-pinene, limonene, spathulenol, caryophyllene oxide, and viridiflorol the main components. However, the abundance of those VOCs were two to ten times higher in B. dracunculifolia than in B. microdonta during the year of study. These Baccharis spp. showed species-specific patterns of VOCs expression according to the seasonality, and interestingly, oxygenated compounds (trans-pinocarveol and myrtenal) increased their abundances at full-flowering stages. The enantiomeric distribution of selected monoterpenes (α- and ß-pinenes, limonene, linalool, terpinen-4-ol, and α-terpineol) presented differential values for both Baccharis spp., meaning that Es-GC might be a useful tool for differentiating chemically both species in Uruguay for genuineness determination purposes.

Ionic liquids as water-compatible GC stationary phases for the analysis of fragrances and essential oils: Quantitative GC-MS analysis of officially-regulated allergens in perfumes.

Qualitative and quantitative determination of volatile markers in aqueous based fragrances assumes ever-increasing importance, because of both the need for quality control and the safety-regulatory limitations introduced for several compounds. This study reports and critically discusses the results of applying new water-compatible ionic-liquid (IL) GC stationary phases, based on phosphonium and imidazolium derivative cations combined with trifluoromethanesulphonate (Watercol™) to the direct quantitative analysis of aqueous samples in the perfume field with GC-MS. Narrow-bore columns of different lengths, especially prepared for this study, were adopted to minimize the amount of water reaching the MS detector after GC separation. All GC-MS analysis steps were investigated, to achieve results compatible with quality control requirements for the volatiles of interest in this field, in terms of LODs, LOQs, and repeatability. Reliability of the GC-MS results was demonstrated by determining volatile allergens in two commercial perfumes, as per EU regulations concerning no-declaration limits for leave-on (0.001%) and rinse-off (0.01%) cosmetic products.

Identification of Plant Compounds Involved in the Microbe-Plant Communication During the Coinoculation of Soybean with Bradyrhizobium elkanii and Delftia sp. strain JD2.

Delftia sp. strain JD2 is a betaproteobacterium characterized as a plant growth-promoting bacterium with a 'helper' function, enhancing the performance of rhizobial inoculant strains during the coinoculation of alfalfa and clover. In this work we analyzed i) the effect of the coinoculation with Bradyrhizobium elkanii and Delftia sp. strain JD2 strains on the performance of soybean plants and ii) the production of a few secondary plant metabolites that would explain the positive effect of coinoculation on the growth and development of soybean plants. The results showed a beneficial effect of coinoculation on soybean growth, nodulation rate, and pulse yield, with the concomitant benefit for the agricultural economy. In addition, based on a metabolomics approach, we demonstrated that a different pattern of plant metabolites is being produced at different stages of plant growth. The new information suggests that the coinoculation of soybean changes the primary and secondary metabolism of the plant, including changes in the metabolic status of main and secondary nodules within the plant. The relevance of producing a different pattern of photosynthetic and photoprotective pigments, flavonoids, organic acids, and carbohydrates are discussed. Finally, we propose that JD2 could be used together with bradyrhizobia to manipulate the chemical composition of plant tissues, promoting the nutritional benefits and health of soybean.

Identification and Quantification of Cocaine and Active Adulterants in Coca-Paste Seized Samples: Useful Scientific Support to Health Care.

Adulteration is a common practice in the illicit drugs market, but the psychoactive and toxic effects provided by adulterants are clinically underestimated. Coca-paste (CP) is a smokable form of cocaine which has an extremely high abuse liability. CP seized samples are sold adulterated; however, qualitative and quantitative data of CP adulteration in forensic literature is still scarce. Besides, it is unknown if adulterants remain stable when CP is heated. This study was designed to report the chemical content of an extensive series of CP seized samples and to demonstrate the stability (i.e., chemical integrity) of the adulterants heated. To achieve this goal, the following strategies were applied: (1) a CP adulterated sample was heated and its fume was chemically analyzed; (2) the vapor of isolated adulterants were analyzed after heating; (3) plasma levels of animals exposed to CP and adulterants were measured. Ninety percent of CP seized samples were adulterated. Adulteration was dominated by phenacetin and caffeine and much less by other compounds (i.e., aminopyrine, levamisole, benzocaine). In the majority of CP analyzed samples, both cocaine and caffeine content was 30%, phenacetin 20% and the combination of these three components reached 90%. Typical cocaine pyrolysis compounds (i.e., BA, CMCHTs, and AEME) were observed in the volatilized cocaine and CP sample but no pyrolysis compounds were found after isolated adulterants heating. Cocaine, phenacetin, and caffeine were detected in plasma. We provide current forensic data about CP seized samples and demonstrated the chemical integrity of their adulterants heated.

Volatile Constituents from Baccharis spp. L. (Asteraceae): Chemical Support for the Conservation of Threatened Species in Uruguay.

Chemical bioprospecting is an important tool for generating knowledge regarding local human-threatened floras and for conservation management. For Baccharis L. (Asteraceae), several volatile components have been reported for Brazil, Argentina, Bolivia, and Chile as a result of bioprospection, but not for Uruguayan flora, which is composed of more than 50 native species. In this work, through collection of aerial parts of different species and volatile simultaneous-distillation extraction and gas chromatography-mass spectrometry analyses, twelve native species of Baccharis were studied (B. articulata, B. cultrata, B. genistifolia, B. gibertii, B. gnaphalioides, B. ochracea, B. phyteumoides, B. punctulata, B. crispa, B. dracunculifolia, B. linearifolia subsp. linearifolia, and B. spicata). A detailed analysis of the male and female volatile composition was conducted for the last four species. The profiles of B. cultrata, B. genistifolia, B. gibertii, and B. gnaphalioides are reported for the first time. Because half of the species analyzed in this work are in Uruguay and are threatened or potentially threatened by human economic activities, the importance of their conservation as natural, sustainable resources is highlighted.

De Novo Synthesis of Benzenoid Compounds by the Yeast Hanseniaspora vineae Increases the Flavor Diversity of Wines.

Benzyl alcohol and other benzenoid-derived metabolites of particular importance in plants confer floral and fruity flavors to wines. Among the volatile aroma components in Vitis vinifera grape varieties, benzyl alcohol is present in its free and glycosylated forms. These compounds are considered to originate from grapes only and not from fermentative processes. We have found increased levels of benzyl alcohol in red Tannat wine compared to that in grape juice, suggesting de novo formation of this metabolite during vinification. In this work, we show that benzyl alcohol, benzaldehyde, p-hydroxybenzaldehyde, and p-hydroxybenzyl alcohol are synthesized de novo in the absence of grape-derived precursors by Hanseniaspora vineae. Levels of benzyl alcohol produced by 11 different H. vineae strains were 20-200 times higher than those measured in fermentations with Saccharomyces cerevisiae strains. These results show that H. vineae contributes to flavor diversity by increasing grape variety aroma concentration in a chemically defined medium. Feeding experiments with phenylalanine, tryptophan, tyrosine, p-aminobenzoic acid, and ammonium in an artificial medium were tested to evaluate the effect of these compounds either as precursors or as potential pathway regulators for the formation of benzenoid-derived aromas. Genomic analysis shows that the phenylalanine ammonia-lyase (PAL) and tyrosine ammonia lyase (TAL) pathways, used by plants to generate benzyl alcohols from aromatic amino acids, are absent in the H. vineae genome. Consequently, alternative pathways derived from chorismate with mandelate as an intermediate are discussed.

Recent findings in the chemistry of odorants from four Baccharis species and their impact as chemical markers.

Baccharis is a widespread genus belonging to the Asteraceae family that includes almost 400 species exclusively from the Americas. Even when studied in detail, the taxonomic classification among species from this genus is not yet fully defined. Within the framework of our study of the volatile composition of the Baccharis genus, four species (B. trimera, B. milleflora, B. tridentata, and B. uncinella) were collected from the 'Campos de Cima da Serra' highlands of the Brazilian state of Rio Grande do Sul. The aerial parts were dried and extracted by the simultaneous distillation extraction (SDE) procedure. This is the first time that SDE has been applied to obtain and compare the volatile-extract composition in the Baccharis genus. Characterization of the volatile extracts allowed the identification of 180 peaks with many coeluting components; these latter being detailed for the first time for this genus. The multivariate statistical analyses allowed separating the volatile extracts of the four populations of Baccharis into two separate groups. The first one included the B. milleflora, B. trimera, and B. uncinella volatile extracts. The three species showed a high degree of similarity in their volatile composition, which was characterized by the presence of high contents of sesquiterpene compounds, in particular of spathulenol. The second group comprised the extract of B. tridentata, which contained α-pinene, ß-pinene, limonene, and (E)-ß-ocimene in high amounts.

Impact of gas chromatography and mass spectrometry combined with gas chromatography and olfactometry for the sex differentiation of Baccharis articulata by the analysis of volatile compounds.

The Baccharis genus has more than 400 species of aromatic plants. However, only approximately 50 species have been studied in oil composition to date. From these studies, very few take into consideration differences between male and female plants, which is a significant and distinctive factor in Baccharis in the Asteraceae family. Baccharis articulata is a common shrub that grows wild in south Brazil, northern and central Argentina, Bolivia, Paraguay and Uruguay. It is considered to be a medicinal plant and is employed in traditional medicine. We report B. articulata male and female volatile composition obtained by simultaneous distillation-extraction technique and analyzed by gas chromatography with mass spectrometry. Also, an assessment of aromatic differences between volatile extracts was evaluated by gas chromatography with olfactometry. The results show a very similar chemical composition between male and female extracts, with a high proportion of terpene compounds of which ß-pinene, limonene and germacrene D are the main components. Despite the chemical similarity, great differences in aromatic profile were found: male plant samples exhibited the strongest odorants in number and intensity of aromatic attributes. These differences explain field observations which indicate differences between male and female flower aroma, and might be of ecological significance in the attraction of pollinating insects.