Reporting effective extraction methodology and chemical characterization of bioactive components of under explored Platycladus orientalis (L.) Franco from semi-arid climate

The bioactive ingredients of many essential oils are complex and difficult to reproduce synthetically. In the present study, the influence of extraction method on relative extraction of bioactive compounds of essential oil of Platycladus orientalis (L.) Franco (Thuja orientalis L. is a synonym of it) leaves gathered from semi-arid climate was studied. A higher yield of essential oil was obtained by hydrodistillation (0.1%) as compared to steam distillation (0.07%) under newly optimized conditions. Initial analysis of these oils by TLC showed the presence of different polarity groups ranging from non-polar terpene hydrocarbons to polar terpenoid alcohols. GC-MS analysis revealed that major component of hydrodistilled essential oil of Platycladus orientalis (L.) Franco leaves was α-pinene (17.83%) and steam distilled essential oil contained α-cedrol (12.44%). The results obtained in the present study emphasize that suitable extraction technique should be used to obtain particular component of interest.     

Applying the hydrodistillation process to Pentadiplandra brazzeana Baill. root: a chemical assessment

A chemical study of the volatile components obtained by applying the hydrodistillation and reflux processes to Pentadiplandra brazzeana roots was performed by GC-FID and GC-MS. The hydrodistillation process showed a total yield of 0.97% with 0.11% of essential oil and 0.86% of volatile compounds from the aqueous reaction medium; in the reflux process, the volatile extract yield was 1.03%. Benzylic-type isothiocyanates were the major degradation products of glucosinolates in the essential oil (95.0%); the CH₂Cl₂ extracts obtained from the aqueous solutions were characterised by alcohols and amines in both processes. This study has shown that during hydrodistillation, only 10% of the glucosinolate degradation products are recovered in the essential oil whereas 90% remain in the aqueous medium, being converted into alcohols and amines. The relative percentages of the different chemical classes recovered in our experimental conditions are discussed in relation with the glucosinolate composition in the raw material.     

Comparison of different extraction methods for the determination of essential oils and related compounds from aromatic plants and optimization of solid-phase microextraction/gas chromatography

Different extraction methods for the subsequent gas chromatographic determination of the composition of essential oils and related compounds from marjoram (Origanum majorana L.), caraway (Carum carvi L.), sage (Salvia officinalis L.), and thyme (Thymus vulgaris L.) have been compared. The comparison was also discussed with regard to transformation processes of genuine compounds, particularly in terms of expenditure of time. Hydrodistillation is the method of choice for the determination of the essential oil content of plants. For investigating the composition of genuine essential oils and related, aroma-active compounds, hydrodistillation is not very useful, because of discrimination and transformation processes due to high temperatures and acidic conditions. With cold solvent extraction, accelerated solvent extraction, and supercritical fluid extraction, discrimination of high and non-volatile aroma-active components as well as transformation processes can be diminished, but non-aroma-active fats, waxes, or pigments are often extracted, too. As solid-phase microextraction is a solvent-free fully automizable sample preparation technique, this was the most sparing to sensitive components and the most time-saving method for the rapid determination of the aroma compounds composition in marjoram, caraway, sage, and thyme. Finally, solid-phase microextraction could be successfully optimized for the extraction of the aroma components from the plants for their subsequent gas chromatographic determination.     

Application of Comprehensive Two‐Dimensional Gas Chromatography (GC×GC) to the Qualitative Analysis of Essential Oils

This paper investigates the separation of moderately complex samples by comprehensive two‐dimensional gas chromatography (GC×GC). The analysis of peppermint (Mentha piperita) and spearmint (Mentha spicata) essential oil components, including acetates, alcohols, furans, ketones, sesquiterpenes, and terpenes, was achieved by one‐dimensional gas chromatography with quadrupole mass spectrometry detection (GC/MSD) and GC×GC with flame ionization detection. Peppermint essential oil was found to contain 89 identifiable peaks by GC×GC compared to 30 peaks in the GC/MSD chromatogram. Likewise, 68 peaks were found in the GC×GC chromatogram of spearmint (compared to 28 in GC/MSD). Plots of the first dimension versus second dimension retention times provided a fingerprint of the two essential oils, which revealed 52 similar compounds between the two essential oils as opposed to 18 matches by 1D GC.     

Chemical composition and antibacterial activity of the essential oil from Agathis dammara (Lamb.) Rich fresh leaves

The essential oil of fresh leaves from Agathis dammara (Lamb.) Rich was extracted using hydro-distillation, and GC-FID and GC–MS were used to analyse the essential oil. Nineteen compounds were identified, among which the major components were limonene (36.81%), β-bisabolene (33.43%) and β-myrcene (25.48%). In the antibacterial test, disc diffusion method and micro-well dilution assay proved that the essential oil had significant antibacterial activities. The inhibition zones against Staphylococcus aureus and Pseudomonas aeruginosa were 23.7 and 23 mm, respectively, which demonstrated that the inhibition effects were greater than positive control (10 μg/disc streptomycin). And the lowest MIC value of the essential oil was found against S. aureus (1.25 mg/mL) and Bacillus subtilis (1.25 mg/mL). This is the first report on the antibacterial activities of A. dammara essential oil.     

Volatile oil analysis of aerial parts of Boerhavia coccinea (Mill.)

Volatile oil of the aerial part of Boerhavia coccinea was obtained by Clevenger-type apparatus, the chemical components were analysed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC–MS). Twenty constituents were recognised in the oil which accounted for 98.05% of it. This was characterised by high level of ethers (29.85%), while most dominant compound was phytol (24.02%). The essential oil of B. coccinea mainly consisted ethers and alcohols, which is being reported for the first time.     

Comparative elucidation of phenolic compounds in Albanian olive oils using LC-DAD-ESI-MS/MS

Abstract

Olive oils may provide health benefits, including the prevention of coronary heart diseases, cancers, and the modification of immune and inflammatory responses. These benefits mainly originate from the phenolic compounds found in olive oil. There has been no study on the advanced characterization of Albanian olive oils from various cultivars regarding phenolic compounds. Hence, a comprehensive characterization of phenolic compounds is carried out in Albanian monocultivar virgin olive oils from five different cultivars, including Kalinjot, Bardhi Tirana, Ulliri-i-Zi Tirana, Krips Kruja, and Bardhi Kruja for the first time. Liquid chromatography coupled to diode array detection and electrospray ?onization tandem mass spectrometry (LC-DAD-ESI-MS/MS) is employed for the determination of phenolic compounds. In total, 18 compounds were identified in all samples, including phenolic alcohols, phenolic acids, secoiridoids, flavonoids, and phenolic aldehydes. Significant quantitative differences were detected among the cultivars, with the highest concentrations detected in virgin olive oil (VOO) from cv. Ulli-i-Zi. Secoiridoids were found in abundance, in general, followed by phenolic alcohols, and in this group, 3,4-DHPEA-EDA and p-HPEA-EDA stood out as dominant compounds, especially in Kalinjot virgin olive oils. Regarding phenolic alcohols, 3,4-DHPEA-AC was determined as the main phenolic compound. Phenolic profiles were found to be significantly different among the olive oil samples of different cultivars. Principal component analyses (PCA) displayed the differentiation of samples in terms of phenolic compounds.     

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.     

三种丁香花精油的挥发性成分比较分析

为了解紫丁香、白丁香和红丁香花蕾精油样品挥发性成分的差异,采用气相色谱-质谱联用技术（GC-MS）分析了三种丁香花精油样品的挥发性成分,并对三者的挥发性成分进行了主成分分析和聚类分析。结果从紫丁香、白丁香和红丁香精油中分别解析出46、64和56种挥发性物质,包括烷烃类、酯类、醇类、酮类、烯烃类、酚类、有机酸等,其中共有的挥发性成分为9种。三种丁香花精油样品的挥发性成分比较分析显示,酯类是含量最高的挥发性成分,其次是烷烃类,并且这两类物质在不同品种的丁香花精油中含量不同。统计分析结果表明三种样品的挥发性成分之间没有明显差别。本研究为增加丁香花精油的应用范围提供了理论依据。     

Investigation of the chemical composition–antibacterial activity relationship of essential oils by chemometric methods

The antibacterial effects of Thymus vulgaris (Lamiaceae), Lavandula angustifolia (Lamiaceae), and Calamintha nepeta (Lamiaceae) Savi subsp. nepeta var. subisodonda (Borb.) Hayek essential oils on five different bacteria were estimated. Laboratory control strain and clinical isolates from different pathogenic media were researched by broth microdilution method, with an emphasis on a chemical composition–antibacterial activity relationship. The main constituents of thyme oil were thymol (59.95%) and p-cymene (18.34%). Linalool acetate (38.23%) and β-linalool (35.01%) were main compounds in lavender oil. C. nepeta essential oil was characterized by a high percentage of piperitone oxide (59.07%) and limonene (9.05%). Essential oils have been found to have antimicrobial activity against all tested microorganisms. Classification and comparison of essential oils on the basis of their chemical composition and antibacterial activity were made by utilization of appropriate chemometric methods. The chemical principal component analysis (PCA) and hierachical cluster analysis (HCA) separated essential oils into two groups and two sub-groups. Thyme essential oil forms separate chemical HCA group and exhibits highest antibacterial activity, similar to tetracycline. Essential oils of lavender and C. nepeta in the same chemical HCA group were classified in different groups, within antibacterial PCA and HCA analyses. Lavender oil exhibits higher antibacterial ability in comparison with C. nepeta essential oil, probably based on the concept of synergistic activity of essential oil components.     

Chemical composition and antibacterial activity of the essential oil from Pyrrosia tonkinensis (Giesenhagen) Ching

The present study aimed to analyse the chemical components of the essential oil from Pyrrosia tonkinensis by GC-MS and evaluate the in vitro antibacterial activity. Twenty-eight compounds, representing 88.1% of the total essential oil, were identified and the major volatile components were trans-2-hexenal (22.1%), followed by nonanal (12.8%), limonene (9.6%), phytol (8.4%), 1-hexanol (3.8%), 2-furancarboxaldehyde (3.5%) and heptanal (3.1%). The antibacterial assays showed that the essential oil of P. tonkinensis had good antibacterial activities against all the tested microorganisms. This paper first reported the chemical composition and antimicrobial activity of the essential oil from P. tonkinensis.     

Analysis of the Essential Oil of Elsholtzia ciliate Aerial Parts and Its Insecticidal Activities against Liposcelis bostrychophila

Water‐distilled essential oil from Elsholtzia ciliate (Labiatae) aerial parts at flowering stage was analyzed by gas chromatography/mass spectrometry (GC/MS). Thirty‐six compounds, accounting for 98.3% of the total oil content, were identified, and the main components of the essential oil were dehydroelsholtzia ketone (26.5%), (R)‐carvone (16.6%), elsholtzia ketone (14.6%), and D ‐limonene (4.1%). The essential oil contained higher amounts of monoterpenoids (83.4%) than of sesquiternoids (8.3%). Bioactivity‐directed chromatographic separation of the essential oil on repeated silica gel columns led to the isolation of three monoterpenoids. The essential oil possessed fumigant toxicity against the booklice (Liposcelis bostrychophila) with an LC₅₀ value of 475.2 μg/l, while the isolated constituents, (R)‐carvone, dehydroelsholtzia ketone, and elsholtzia ketone had LC₅₀ values of 417.4, 658.2, and 547.3 μg/l, respectively. The essential oil also exhibited contact toxicity against L. bostrychophila with an LC₅₀ value of 145.5 μg/cm². (R)‐Carvone, dehydroelsholtzia ketone, and elsholtzia ketone exhibited acute toxicity against the booklice with LC₅₀ values of 57.0, 151.5, and 194.1 μg/cm², respectively. The results indicated that the essential oil and the isolated constituents have potential for the development into natural insecticides/fumigants for the control of insects in stored grains.     

Oregano Essential Oil Interactions with Photogenerated Singlet Molecular Oxygen

Essential oils are a mixture of volatile compounds, products of the secondary metabolism of plants. Once extracted, they can be deteriorated losing their organoleptic and therapeutic properties due to various environmental factors, being light exposure in aerobic conditions the main cause. In this work, the oregano essential oil extraction and characterization from Origanum vulgare plants grown in the experimental field of the FTU-UNSL and its photodegradation in MeOH:H₂O 60:40 v/v solvent were studied. Characterization by EIMS and NIST Mass Spectrometry indicates the main compounds of oregano essential oil, quantified in the extracted oil by GC-MS, are carvacrol (7.14%) and thymol (47.37%). Degradation of essential oil and its two major components can be caused by reactive oxygen species photogenerated from endogenous sensitizers as riboflavin. Our results suggest degradation occurs involving singlet molecular oxygen. Interaction of carvacrol and thymol with singlet oxygen is mainly a physical process, while essential oil has an important reactive component, which indicates there might be other constituents which could contribute to reactive photoprotection. The effect of simultaneous presence of oregano essential oil and tryptophan amino acid—used as a photooxidizable model under riboflavin-photosensitizing conditions—was studied in order to evaluate the possible photoprotection exerted by the essential oil.     

Rapid analysis of the essential oil components of dried Zanthoxylum bungeanum Maxim by Fe2O3‐magnetic‐microsphere‐assisted microwave distillation and simultaneous headspace single‐drop microextraction followed by GC–MS

In this work, microwave distillation assisted by Fe₂O₃ magnetic microspheres (FMMS) and headspace single‐drop microextraction were combined, and developed for determination of essential oil compounds in dried Zanthoxylum bungeanum Maxim (ZBM). The FMMS were used as microwave absorption solid medium for dry distillation of dried ZBM. Using the proposed method, isolation, extraction, and concentration of essential oil compounds can be carried out in a single step. The experimental parameters including extraction solvent, solvent volume, microwave power, irradiation time, and the amount of added FMMS, were studied. The optimal analytical conditions were: 2.0 μL decane as the extraction solvent, microwave power of 300 W, irradiation time of 2 min, and the addition of 0.1 g FMMS to ZBM. The method precision was from 4 to 10%. A total of 52 compounds were identified by the proposed method. The conventional steam distillation method was also used for the analysis of essential oil in dried ZBM and only 31 compounds were identified by steam distillation method. It was found that the proposed method is a simple, rapid, reliable, and solvent‐free technique for the determination of volatile compounds in Chinese herbs.     

Chemical composition of essential oil from Jordanian Lupinus varius L.

The chemical composition of essential oil obtained by hydrodistillation from flowering shoots of Lupinus varius L. was analyzed by GC–FID and GC–MS. Chemical analysis of this oil showed that it includes a complex mixture of aldehydes, alcohols, esters and mono- and sesquiterpenes. Forty one compounds were characterized in the oil. The major components of the oil were 6,10,14-trimethyl-2-pentadecanone (20.5%), pentadecanal (10.2%), (E) nerolidol (8.43%), carracol ethyl ether (4.3%), α-humulene (3.6%), (2Z,13E)-ocatadeca-2,13-dien-l0-ol (3.2%) and caryophyllene-5-ol (2.7%).     

Fumigant and repellent activities of essential oil extracted from Artemisia dubia and its main compounds against two stored product pests

The major chemical constituents of the essential oil extracted from Artemisia dubia wall. ex Bess. (Family: Asteraceae) were found as terpinolene (19.02%), limonene (17.40%), 2,5-etheno[4.2.2]propella-3,7,9-triene (11.29%), isoelemicin (11.05%) and p-cymene-8-ol (5.93%). Terpinolene and limonene were separated as main components from the essential oil. The essential oil showed fumigant toxicity against Tribolium castaneum and Liposcelis bostrychophila with LC₅₀ values of 49.54 and 0.74 mg/L, respectively. The essential oil and isolated compounds of A. dubia showed repellency activities against both insects. Terpinolene and limonene showed the fumigant toxicity against T. castaneum. Terpinolene showed obvious fumigant toxicity against L. bostrychophila. The results indicated that the essential oil of A. dubia had potential to be developed into natural insecticides for controlling stored product pests.     

Composition of essential oils from <Emphasis Type="Italic">Salvia anatolica</Emphasis>, a new species endemic from Turkey

The component composition of essential oils produced by steam distillation from flower heads, leaves, and stems of Salvia anatolica (Lamiaceae), a recently described new species endemic from Turkey, was studied by GC/FID and GC/MS. A total of 127 volatile components representing 96% of the oil was identified in essential oil from flower heads and leaves. It was found that the principal oil components of flower heads and leaves were α-pinene (10.9%), β-pinene (6.7%), α-copaene (6.3%), heptacosane (6.2%), and hexadecanoic acid (5.0%). A total of 109 volatile compounds representing 87.9% of the oil was characterized in essential oil isolated from stems. The principal oil components of stems were identified as hexadecanoic acid (27.2%), tetradecanoic acid (15.2%), dodecanoic acid (5.5%), and α-copaene (5.0%). __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 552–555, November–December, 2007.     

Volatiles composition and antioxidant activity Inula oculus-christi L. from Serbia

Abstract

The chemical composition of the essential oil and the volatiles obtained by static headspace (HS) of Inula oculus-christi L. is presented. The GC-MS analysis of the hydrodistilled oil resulted in the identification of 90 components, representing 92.7% of the oil. The most abundant compounds were: caryophyllene oxide (9.8%), trans-longipinocarveol (9.2%), eucalyptol (7.3%) and intermedeol (6.2%). The major constituent of I. oculus-christi L. HS volatiles was eucalyptol (87.4%). The antioxidant activity was evaluated by four different methods: 2,2-diphenyl-1-picryl-hydrazylhydrate free radical assay (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method, total reducing power (TRP), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC). Total phenolic content in (TPC) examined oil was 177.95?µg GAE/mg oil. Radical scavenging potential of the oil was promising RSC-DPPH was 57.4% and RSC-ABTS was 82.7%.

     

Epilobium angustifolium L. Essential Oil—Biological Activity and Enhancement of the Skin Penetration of Drugs—In Vitro Study

Epilobium angustifolium L. is a popular medicinal plant found in many regions of the world. This plant contains small amounts of essential oil whose composition and properties have not been extensively investigated. There are few reports in the literature on the antioxidant and antifungal properties of this essential oil and the possibility of applying it as a potential promoter of the skin penetration of drugs. The essential oil was obtained by distillation using a Clavenger type apparatus. The chemical composition was analyzed by the GC-MS method. The major active compounds of E. angustifolium L. essential oil (EOEa) were terpenes, including α-caryophyllene oxide, eucalyptol, β-linalool, camphor, (S)-carvone, and β-caryophyllene. The analyzed essential oil was also characterized by antioxidant activity amounting to 78% RSA (Radical Scavenging Activity). Antifungal activity against the strains Aspergillus niger, A. ochraceus, A. parasiticum, and Penicillium cyclopium was also determined. The largest inhibition zone was observed for strains from the Aspergillus group. The EOEa enhanced the percutaneous penetration of ibuprofen and lidocaine. After a 24 h test, the content of terpene in the skin and the acceptor fluid was examined. It has been shown that the main compounds contained in the essential oil do not penetrate through the skin, but accumulate in it. Additionally, FTIR-ATR analysis showed a disturbance of the stratum corneum (SC) lipids caused by the essential oil application. Due to its rich composition and high biological activity, EOEa may be a potential candidate to be applied, for example, in the pharmaceutical or cosmetic industries. Moreover, due to the reaction of the essential oil components with SC lipids, the EOEa could be an effective permeation enhancer of topically applied hydrophilic and lipophilic drugs.     

Polydimethylsiloxane/graphene oxide/β-cyclodextrin sponge as a solid-phase extraction sorbent coupled with gas chromatography-mass spectrometry for rapid adsorption and sensitive determination of lavender essential oil

An adsorbent polydimethylsiloxane/graphene oxide/β-cyclodextrin sponge, which possessed the merits of high surface area, chemical stability, environment friendly, and excellent extraction capacity, was successfully fabricated. Based on the advantages, a novel microwave-assisted headspace solid-phase extraction method for lavender essential oil using polydimethylsiloxane/graphene oxide/β-cyclodextrin sponge as adsorbents was developed in this study. Various experimental parameters were studied. The optimal extraction conditions were as follows: 1 mg/mL as dopamine solution concentration, graphene oxide dosages of 30 mg, microwave power of 700 W, microwave irradiation time of 10 min, and desorption solvent of n-hexane. Under the optimal extraction condition, linearities ranging from 10 to 800 ng were achieved for six representative compounds with a correlation coefficients value of >0.99. The intra-day and inter-day precisions were in the ranges of 0.40–1.56 and 0.67–2.56%, respectively. Finally, the proposed technique was applied to analyze essential oil constituents in 14 samples of three lavender varieties, and 48 compounds were identified. Lavender varieties were distinguished using principal component analysis and partial least squares discriminant analysis. The results showed that the method developed in this study is a novel, simple, and sensitive method for the determination of essential oil in complex plant samples.