Essential oil composition of three accessions of Dracocephalum heterophyllum Benth. cultivated at Palampur, India

Seeds of three accessions of Dracocephalum heterophyllum growing wild in high altitude locations in the cold desert regions of trans-Himalaya were collected and propagated under polyhouse conditions at IHBT Palampur to evaluate, compare their growth performance and essential oil composition. Three different chemotypes viz., citronellol-rose oxides type, citronellol type and citronellal-trans rose oxide type were identified. Samples of essential oils were distilled separately from leaves and inflorescence of all the three cultivated accessions and characterised by capillary GC and GC-MS techniques, which showed variation in the volatile constituents. In all the three accessions, citronellol was higher in the inflorescence oils as compared to leaf oils. Rose oxides, which are important high odour value cyclic monoterpene ethers were found in the essential oil samples of leaves as well as in the inflorescence of accession II, whereas these constituents were absent in the leaves of other two accessions. The essential oil from the inflorescence part of accession I was devoid of both cis and trans isomers of rose oxide, while accession III contained only one isomer of trans rose oxide. Under polyhouse conditions, seed germination was higher in accession III, whereas aerial biomass was higher in accession I. In comparison to other accessions, yield of volatile oil was higher in both leaf and inflorescence of accessions I, whereas accession II had higher oil yield from inflorescence. This is the first report of volatile oil composition of three accessions of D. heterophyllum cultivated at Palampur having potential as a new source of high valued essential oil for introduction in the perfumery industry.     

Novel HPTLC-densitometric method for concurrent quantification of linalool and thymol in essential oils

Monoterpenes, linalool and thymol have been widely used in not only the treatments of several diseases but also food flavouring, dental, perfumery, and toilet products. Plants of the several Lamiaceae family are good sources of linalool and thymol. A rapid, simple, and precise high-performance thin layer chromatography (HPTLC) method was developed for the concurrent estimation of linalool and thymol, and this method was orchestrated using the essential oils extracted from two Lamiaceae plants leaves i.e. O. basilicum and T. vulgaris. Two standards were separated using pre-coated thin-layer chromatography glass plates. The developed HPTLC method was validated by following ICH guidelines (linearity; limit of detection, LOD; limit of quantitation; specificity; accuracy; precision; and robustness). The calibration curves of both the compounds were linear (100–700 ng/spot), with a correlation coefficient (r²) of >999. The developed HPTLC method was effectively applied to the concurrent detection and quantification of linalool and thymol in commercial essential oils.     

Determination of trace elements in the Lavender inflorescence (Lavandula angustifolia Mill.) — Lavender oil system

Bulgaria is a famous world producer of essential oils. Quality control of the lavender oils produced is an important analytical task in view of their wide use in perfumery and cosmetics, the food industry and aromatherapy. The present paper studies the relationship between the trace elements content in lavender inflorescence (Lavandula angustifolia Mill.) and in lavender oil derived from this inflorescence. Three model regions were investigated: two of them are situated far from industrial areas — the village of Zelenikovo and the town of Pavel Banya, and one region is located near the Plovdiv Non-Ferrous Metallurgical Plant. The content of the elements Cd, Cr, Cu, Fe, Mn and Pb in plants was determined after acid digestion by flame and electrothermal atomic absorption spectrometry (ETAAS). Lavender oils were analyzed directly by ETAAS. The results undoubtedly show that there is no strong correlation between the trace elements content in inflorescence and in essential oils. It might be assumed that the trace elements present and accumulated in the inflorescence do not pass in lavender oil during the production by steam distillation.     

Essential oil composition of aerial parts of Micromeria persica Boiss. from Western of Shiraz,Iran

Micromeria persica Boiss. is medicinal and aromatic plant, belonging to the Lamiaceae family. The chemical composition of the essential oils (EOs) from aerial parts of M. persica were extracted using hydro-distillation method and analysed using GC and GC–MS. Fifty-two compounds were identified in the EOs of aerial parts of M. persica. The main chemical compositions were n-hexadecanoic acid (14.9%), thymol (9.5%), linoleic acid (8.0%), carvacrol (5.6%), (E)-nerolidol (5.5%), linolenic acid (5.5%), α-cadinol (2.7%), linalool (2.7%), borneol (2.6%), caryophyllene oxide (2.3%) and pulegone (2.0%). Presence of borneol, thymol, carvacrol and pulegone suggests the potential of this plant as a flavouring source in the food industry, being used in perfumery and cosmetics industry, vitamin E synthesis and exhibit strong fungicidal, antibacterial and antimicrobial activities.     

Separation of very hydrophobic analytes by micellar electrokinetic chromatography. I. Optimization of the composition of the sample solution for the determination of the aromatic ingredients of sassafras and other essential oils of forensic interest

A micellar electrokinetic chromatographic method using UV and (UV)LIF detection in-line was developed for the determination of aromatic constituents, mainly allylbenzenes in essential oils. The method optimization included the optimization of the composition of the separation electrolyte using ACN and urea to reduce retention factors and CaCl(2) to widen the migration time window. In addition, it was necessary to optimize the composition of the sample solution which included the addition of a neutral surfactant at high concentration. With the optimized method, the determination of minor constituents in essential oils was possible despite of the presence of a structurally related compound being in a molar ratio excess of 1000:1. The use of UV and LIF-detection in-line enabled the direct comparison of the two detection traces using an electrophoretic mobility x-axis instead of the normal time-based scale. This simplifies the assignment of signals and enhances repeatability. The method developed was successfully applied to the determination of minor and major constituents in herbal essential oils, some of them being forensically relevant as sources of precursors for synthetic drugs.     

Polymeric Encapsulates of Essential Oils and Their Constituents: A Review of Preparation Techniques,Characterization, and Sustainable Release Mechanisms

Natural polymer based encapsulation of essential oil (EO) is one of the emerging and challenging area of research in perfumery, cosmetics, flavoring agents, preservatives, therapeutics, etc. The knowledge of formulation techniques and physico-chemical properties of the polymers are the basic requirements for the successful encapsulations of essential oils (EOs). This current review article is focused on a comparative account of various formulation techniques based on their applicability. For the first time, it also reviews various physico-chemical techniques used in the analysis of EO encapsulates to determine their stability, structure, surface morphology, and encapsulation efficiency. Further, the mechanisms involved in the release of EOs from encapsulates, along with various factors affecting their release, have also been discussed.     

Chemical composition and variability of the volatile components from inflorescences of Cirsium species

The present study aimed to investigate the chemical composition of the essential oils of inflorescences Cirsium spp. (Asteraceae) by GC/MS method. Essential oils were extracted from the inflorescences of Cirsium pannonicum (Link), Cirsium ligulare Boiss., Cirsium heterophyllum (L.) Hill., Cirsium acaule (L.) Scop., Cirsium oleraceum (L.) Scop., Cirsium dissectum (L.) Hill., Cirsium decussatum (Janka) and Cirsium eriophorum (L.) Scop., using the steam distillation method. A gas chromatography–mass spectrometry method was employed for the analysis of essential oils. Our study shows the differences in chemical composition of volatile oils in the inflorescences of Cirsium spp. The main components of the essential oil were ketones and aldehydes with a long carbon side-chain. Volatile oils also contained small amounts of terpenes: thymol, β-linalool, eugenol, carvacrol and fatty acids with odd number of carbon atoms–waxes. The compounds in the essential oils obtained from inflorescences Cirsium L. species have been identified for the first time.     

Comparison of MAHD with UAE and Hydrodistillation for the Analysis of Volatile Oil From Four Parts of Perilla frutescens Cultivated in Southern China

Three different isolation techniques, specifically microwave-assisted hydrodistillation (MAHD), ultrasound-assisted extraction (UAE), and conventional hydrodistillation (HD) were employed to obtain essential oils from whole plants, leaves, roots, and stems of Perilla frutescens. The essential oils were analyzed using gas chromatography with flame ionization detection and gas chromatography with mass spectrometry. Variations in chemical composition were observed; these were attributed to differences in plant organs. Variations in the percentages of the main constituents of the oils extracted based on plant organ were irregular and affected the quantity and composition of the oils. Oil yields were affected by the method of extraction and extraction organ variation. The maximum volume of oil was extracted from leaves via MAHD and the minimum was extracted from roots via UAE. Oil yields ranged from 0.05% to 0.53%. The contents of essential oil varied significantly with the plant organ. In the essential oils of the plant parts studied were showed a predominance of oxygenated monoterpenes. Variation of extraction methods and organs may influence the oil components either qualitatively or quantitatively.     

Comparison of compositions and antimicrobial activities of essential oils from chemically stimulated agarwood, wild agarwood and healthy Aquilaria sinensis (Lour.) gilg trees

The composition and antimicrobial activity of the essential oils which were obtained from agarwood originated from Aquilaria sinensis (Lour.) Gilg stimulated by the chemical method (S1) were characterized, taking wild agarwood (S2) and healthy trees (S3) respectively as the positive and negative controls. The chemical composition of S1 was investigated by gas chromatography-mass spectrometry (GC-MS). The essential oil of S1 showed a similar composition to that of S2, being rich in sesquiterpenes and aromatic constituents. However, the essential oil of S3 was abundant in fatty acids and alkanes. Essential oils of S1 and S2 had better inhibition activities towards Bacillus subtilis and Staphyloccus aureus, compared with essential oil of S3. Escherichia coli was not sensitive to any of them.     

Study of quantitative and qualitative variations in essential oils of Sicilian Rosmarinus officinalis L.

In this study the chemical characterisation of 10 Sicilian Rosmarinus officinalis L. biotypes essential oils is reported. The main goal of this work was to analyse the relationship between the essential oils yield and the geographical distribution of the species plants. The essential oils were analysed by GC-FID and GC-MS. Hierarchical cluster analysis and principal component analysis statistical methods were used to cluster biotypes according to the essential oils chemical composition. The essential oil yield ranged from 0.8 to 2.3 (v/w). In total 82 compounds have been identified, these represent 96.7–99.9% of the essential oil. The most represented compounds in the essential oils were 1.8-cineole, linalool, α-terpineol, verbenone, α-pinene, limonene, bornyl acetate and terpinolene. The results show that the essential oil yield of the 10 biotypes is affected by the environmental characteristics of the sampling sites while the chemical composition is linked to the genetic characteristics of different biotypes.     

Terpene bioconversion--how does its future look?

The usage of essential oils as such or of volatile fractions thereof is widespread in the flavor and fragrance industry to aromatize perfumery and cosmetic products, foodstuffs, and many household and pharmaceutical products. The increased market share of convenience food together with consumers' request for constant high quality and natural products have established a lasting increase in the demand for natural flavorings that cannot be satisfied by the traditional plant materials. This review summarizes selected work on terpene bioconversion/transformation and focuses on recently published papers dealing with novel strains and products, high product yields, intriguing genetic engineering approaches, and integrated bioprocesses. The future perspectives of an industrial realization of a biotechnological production of terpene-derived natural flavors are critically evaluated.     

Chemical composition,phytotoxic and antifungal properties of Ruta chalepensis L. essential oils

The chemical composition, and phytotoxic and antifungal activities of the essential oils isolated by using hydrodistillation from the aerial parts of Tunisian rue were evaluated. Significant variations were observed among harvest periods. The analysis of the chemical composition by gas chromatography/mass spectrometry showed that 2-undecanone (33.4–49.8%), 2-heptanol acetate (13.5–15.4%) and α-pinene (9.8–11.9%) were the main components. The antifungal ability of rue essential oils was tested by using disc agar diffusion against ten plant pathogenic fungi. A high antifungal activity was observed for the essential oil isolated at flowering developmental phase. Furthermore, rue essential oils showed high level of herbicidal activity against several weeds.     

Comparison of microwave-assisted and conventional hydrodistillation in the extraction of essential oils from mango (Mangifera indica L.) flowers

Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique, in which a microwave oven is used in the extraction process. MAHD and HD methods have been compared and evaluated for their effectiveness in the isolation of essential oils from fresh mango (Mangifera indica L.) flowers. MAHD offers important advantages over HD in terms of energy savings and extraction time (75 min against 4 h). The composition of the extracted essential oils was investigated by GC-FID and GC-MS. Results indicate that the use of microwave irradiation did not adversely influence the composition of the essential oils. MAHD was also found to be a green technology.     

Chemical Composition of Essential Oil from Italian Populations of <em>Artemisia alba</em> Turra (Asteraceae)

The use of essential oils as chemotaxonomic markers could be useful for the classification of Artemisia species and to caracterize biodiversity in the different populations. An analysis of the chemical composition of four essential oils from Italian populations of Artemisia alba Turra (collected in Sicily, Marche and Abruzzo) was investigated. In this paper an in depth study of the significant differences observed in the composition of these oils is reported.     

Drying Effects on Chemical Composition and Antioxidant Activity of Lippia thymoides Essential Oil,a Natural Source of Thymol

Leaves of Lippia thymoides (Verbenaceae) were dried in an oven at 40, 50 and 60 °C and the kinetic of drying and the influence of the drying process on the chemical composition, yield, and DPPH radical scavenging activity of the obtained essential oils were evaluated. The composition of the essential oils was determined with gas chromatography-mass spectrometry and gas chromatography-flame ionization detection analyses. The influence of drying on the chemical composition of the essential oils of L. thymoides was evaluated by multivariate analysis, and their antioxidant activity was investigated via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The Midilli model was the most appropriate to describe the behavior of drying kinetic data of L. thymoides leaves. Thymol was the major compound for all analyzed conditions; the maximum content was obtained from fresh leaves (62.78 ± 0.63%). The essential oils showed DPPH radical scavenging activity with an average of 73.10 ± 12.08%, and the fresh leaves showed higher inhibition (89.97 ± 0.31%). This is the first study to evaluate the influence of drying on the chemical composition and antioxidant activity of L. thymoides essential oils rich in thymol.     

Fleeting Beauty—The World of Plant Fragrances and Their Application

This article is devoted to some aspects of the fragrant substances of plant origin applied in the food industry and perfumery as well. Since antiquity many extractive techniques have been developed to obtain essential oils. Some of them are still applied, but new ones, like microwave or ultrasound-assisted extractions, are more and more popular and they save time and cost. Independently of the procedure, the resulting essential oils are the source of many so-called isolates. These can be applied as food additives, medicines, or can be used as starting materials for organic synthesis. Some substances exist in very small amounts in plant material so the extraction is not economically profitable but, after their chemical structures were established and synthetic procedures were developed, in some cases they are prepared on an industrial scale. The substances described below are only a small fraction of the 2000–3000 fragrant molecules used to make our life more enjoyable, either in food or perfumes. Additionally, a few examples of allelopathic fragrant compounds, present in their natural state, will be denoted and some of their biocidal features will be mentioned as an arising “green” knowledge in agriculture.     

Rapid analysis of the essential oils from dried Illicium verum Hook. f. and Zingiber officinale Rosc. by improved solvent-free microwave extraction with three types of microwave-absorption medium

A new method of extracting essential oils from dried plant materials has been studied. By adding a microwave-absorption medium (MAM) to a reactor, solvent-free microwave extraction (SFME) was improved and can be used to extract essential oils from dried plant material without pretreatment. With a microwave irradiation power of 85 W it took only approximately 30 min to extract the essential oils completely. The whole extraction process is simple, rapid, and economical. Three types of MAM, iron carbonyl powder (ICP), graphite powder (GP), and activated carbon powder (ACP), and two types of dried plant material, Illicium verum Hook. f. and Zingiber officinale Rosc., were studied. The results were compared with those obtained by use of conventional SFME, microwave-assisted hydrodistillation (MAHD), and conventional hydrodistillation (HD), and the conclusion drawn was that improved SFME was a feasible means of extracting essential oils from dried plant materials, because there were few differences between the composition of the essential oils extracted by improved SFME and by the other methods.     

Evaluation of the chemical composition of Brazilian commercial Cymbopogon citratus (D.C.) stapf samples

The concentration and the chemical composition of the essential oils obtained from different samples of Cymbopogon citratus were evaluated. Among the 12 samples investigated (11 dried leaf samples and fresh plant leaves), seven presented essential oil concentrations within the threshold established by the Brazilian legislation. The moisture content was also determined and the majority of the samples presented humidity contents near 12%. The GC and GC/MS analyses of the essential oils led to identification of 22 compounds, with neral and geranial as the two major components. The total percentage of these two compounds varied within the investigated sample oils from 40.7% to 75.4%. In addition, a considerable variation in the chemical composition of the analyzed samples was observed. The process of grinding the leaves significantly decreased (by up to 68%) the essential oil content, as well as the percentage of myrcene in the oils.     

Analysis of essential oils from Voacanga africana seeds at different hydrodistillation extraction stages: chemical composition,antioxidant activity and antimicrobial activity

In this study, essential oils from Voacanga africana seeds at different extraction stages were investigated. In the chemical composition analysis, 27 compounds representing 86.69–95.03% of the total essential oils were identified and quantified. The main constituents in essential oils were terpenoids, alcohols and fatty acids accounting for 15.03–24.36%, 21.57–34.43% and 33.06–57.37%, respectively. Moreover, the analysis also revealed that essential oils from different extraction stages possessed different chemical compositions. In the antioxidant evaluation, all analysed oils showed similar antioxidant behaviours, and the concentrations of essential oils providing 50% inhibition of DPPH-scavenging activity (IC₅₀) were about 25 mg/mL. In the antimicrobial experiments, essential oils from different extraction stages exhibited different antimicrobial activities. The antimicrobial activity of oils was affected by extraction stages. By controlling extraction stages, it is promising to obtain essential oils with desired antimicrobial activities.     

Comparative essential oil composition of aerial parts of Tanacetum dumosum Boiss. from Southern Zagros,Iran.

The essential oils of leaves and flowers of Tanacetum dumosum Boiss., an endemic medicinal shrub, were extracted by using hydrodistillation method and analysed using GC and GC–MS. A total of 43 and 44 compounds were identified in the essential oils from the leaves and flowers of T. dumosum, respectively. The major chemical constituents of leaves oil were borneol (27.9%), bornyl acetate (18.4%), 1,8-cineol (17.5%), α-terpineol (5.3%), cis-chrysanthenyl acetate (3.3%), camphene (2.7%) and terpinene-4-ol (1.9%), while the main components of the flower oil were isobornyl-2-methyl butanoate (41.1%), trans-linalyl oxide acetate (11.9%), 1,8-cineole (7.7%), thymol (4.2%), linalool (3.9%), camphor (2.9%), isobornyl propanoate (2.9%), α-terpineol (2.1%) and caryophyllene oxide (2.0%). Major qualitative and quantitative variations for some main chemical compounds among different aerial parts of T. dumosum were identified. High contents of borneol, bornyl acetate, 1,8-cineol and linalool in the leaves and flowers of T. dumosum show its potential for use in the food and perfumery industry.