Continuous determination of total flavonoids in Platycladus orientalis (L.) Franco by dynamic microwave-assisted extraction coupled with on-line derivatization and ultraviolet-visible detection

This paper describes a new method for the determination of total flavonoids in Platycladus orientalis (L.) Franco. The method was based on dynamic microwave-assisted extraction (DMAE) coupled with on-line derivatization and ultraviolet-visible (UV-vis) detection. The influence of the experimental conditions was tested. Maximum extraction yield was achieved using 80% aqueous methanol of extraction solvent; 80 W of microwave output power; 5 min of extraction time; 1.0 mL min⁻¹ of extraction solvent flow rate. The derivatization reaction between aluminium chloride and flavonoid is one of the most sensitive and selective reactions for total flavonoids determination. The optimized derivatization conditions are as follows: derivatization reagent 1.5% aluminium chloride methanol solution; reaction coil length 100 cm; derivatization reagent flow rate 1.5 mL min⁻¹. The detection and quantification limits obtained are 0.28 and 0.92 mg g⁻¹, respectively. The intra-day and inter-day precisions (R.S.D.) obtained are 1.5% and 4.6%, respectively. Mean recovery is 98.5%. This method was successfully applied to the determination of total flavonoids in P. orientalis (L.) Franco and compared with heat reflux extraction. The results showed that the higher extraction yield of total flavonoids was obtained by DMAE with shorter extraction time (5 min) and small quantity of extraction solvent (5 mL).     

Antioxidant activity of crude extracts and essential oils from flower buds and leaves of Cistus creticus and Cistus salviifolius

Volatile oils from flowers and leaves of C. creticus L. and C. salviifolius L. were extracted by two extraction methods; namely, hydrodistillation and solid-phase micro-extraction (SPME). The chemical composition of essential oils was analyzed by GC and GC–MS. The volatile extracted from leaves and flowers of C. criticus using SPME was dominated by monoterpenes and sesquiterpenes hydrocarbon with α-pinene, camphene and α-cubebene as major components. In hydrodistillation, the oil extracted from leaves was dominated by oxygenated diterpenes and diterpenes hydrocarbon with manoyl oxide and sclarene as major components, whereas, the oil extracted from flowers was dominated by oxygenated diterpenes and diterpenes hydrocarbon with manoyl oxide and abietatriene as major components. The volatile from flowers and leaves of C. salviifolius obtained by SPME were dominated by monoterpenes and sesquiterpenes with δ-3-carene, α-pinene, β-pinene, and E-caryophyllene as major constituents. On the other hand, the oils from flowers and leaves of C. salviifolius obtained by hydrodistillation were dominated by oxygenated diterpenes, diterpenes hydrocarbon and esters with dehydro abietol, abietol, manoyl oxide and methyl octadecenoate as major components. In the leaves, the major components of the oil were manoyl oxide, E-ethyl cinnamate, and Z-ethyl cinnamate. These oils showed weak antioxidant activity when compared to the positive controls α-tocopherol, ascorbic acid, and EDTA, while the crude extracts aq. MeOH, butanol, and water showed good antioxidant activity. Discriminating between the studied plants based on the extraction method was also possible upon applying Principle component analysis (PCA) to the obtained GC–MS data.     

Analysis of terpenoic composition of conifer needle oils by steam distillation/extraction,gas chromatography and gas chromatography-mass spectrometry

Summary The essential oils of Estonian spruce and pine needles have been analysed by a combination of steam distillation/extraction, GC and GC-MS. According to their monoterpene composition Estonian pines belong to a high carene chemotype with monoterpenes representing up to 85% of total oil. Estonian spruce needle oil contains up to 70% of oxygenated terpenes and more limonene and 1,8-cineole than the same spruce species [Picea abies (L.) Karst.] from other localities.A total of 60 components were identified. Coefficients of variation describe the range of component contents in individual trees within the population.     

Supercritical fluid extraction ofCymbopogon citratus (DC.) Stapf

Summary Cymbopogon citratus (DC.) Stapf. is also known as lemon grass; its leaves produce a volatile oil upon steam extraction which is used for medicinal purposes. This work describes the supercritical fluid extraction ofCymbopogon citratus in sequential and dynamic extraction modes. Different modifiers for supercritical carbon dioxide were used for the extractions. Principal compounds in the essential oils were analyzed by GC and GC-MS and identified as neral, geraniol, geranial, nerolic acid and geranic acid. Different chromatographic profiles were obtained when the type and proportion of modifier were changed.     

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.     

Lippia origanoides chemotype differentiation based on essential oil GC‐MS and principal component analysis

Chromatographic (GC/flame ionization detection, GC/MS) and statistical analyses were applied to the study of essential oils and extracts obtained from flowers, leaves, and stems of Lippia origanoides plants, growing wild in different Colombian regions. Retention indices, mass spectra, and standard substances were used in the identification of 139 substances detected in these essential oils and extracts. Principal component analysis allowed L. origanoides classification into three chemotypes, characterized according to their essential oil major components. α‐ and β‐phellandrenes, p‐cymene, and limonene distinguished chemotype A; carvacrol and thymol were the distinctive major components of chemotypes B and C, respectively. Pinocembrin (5,7‐dihydroxyflavanone) was found in L. origanoides chemotype A supercritical fluid (CO₂) extract at a concentration of 0.83±0.03 mg/g of dry plant material, which makes this plant an interesting source of an important bioactive flavanone with diverse potential applications in cosmetic, food, and pharmaceutical products.     

Evaluation of chemical composition,antioxidant and anti-hyperglycemic activities of the essential oil based nanoemulsions of Cinnamomum litseifolium

In the present study, antioxidant and anti-hyperglycemic activities of nanoemulsions of the leaf essential oils of Cinnamomum litseifolium Thwaites collected from two different locations in the Western Ghats namely, Kannikatty, Kalakad Mundandurai Tiger Reserve, Tamil Nadu (Cl¹) and Karamanayar, Agasthyamalai hills, Kerala (Cl²), India were studied. Essential oils were extracted from the leaves and characterized by GC-FID and GC-MS. Slight variation in the composition of leaf essential oils was observed. Essential oil based nanoemulsions were prepared using a surfactant (Tween-80), co-surfactant (propylene glycol) and an emulsifier (lecithin) by homogenization followed by ultra-sonication. Upon characterization, the nanoemulsion of Cl¹ showed better stability than Cl². Both nanoemulsions inhibited α-amylase and α-glucosidase enzymes with IC₅₀ values of 1.998 and 0.780 mg/mL for Cl¹ and 3.587 and 1.455 mg/mL for Cl² respectively.     

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.     

Chemical composition and α-amylase inhibitory activity of the essential oil from Sabina chinensis cv. Kaizuca leaves

Sabina chinensis cv. Kaizuca (SCK) is a variant of S. chinensis L. The essential oil from its leaves exhibited α-amylase inhibitory activity in vitro and the IC₅₀ value was 187.08 ± 0.56 μg/mL. Nineteen compounds were identified from this essential oil by gas chromatography–mass spectrometry (GC-MS) analysis. The major compounds identified were bornyl acetate (42.6%), elemol (20.5%), β-myrcene (13.7%) and β-linalool (4.0%). In order to study the reason of the α-amylase inhibitory activity of this essential oil, the identified compounds were docked with α-amylase by molecular docking individually. Among these compounds, γ-eudesmol exhibited the lowest binding energy (?6.73 kcal/mol), followed by α-copaen-11-ol (?6.66 kcal/mol), cubedol (?6.39 kcal/mol) and α-acorenol (?6.12 kcal/mol). The results indicated that these compounds were the active ingredients responsible for the α-amylase inhibitory activity of essential oil from SCK.     

Essential oil composition and antibacterial activity of Lindera nacusua (D. Don) Merr.

This study represents the first report on the chemical composition and biological activity of the essential oils from the leaves of Lindera nacusua (D. Don) Merr. Twenty-two compounds were identified and quantified, and the major components of the oil were Caryophyllene oxide (8.79%), Hexahydrofarnesyl acetone (6.83%), β-Selinene (5.02%), Neophytadiene (4.53%), Palmitic acid (4.42%), Phytol (4.36%), α-Copaene (3.89%), 4a,5,8,8a-β-Tetrahydro-2,4,5-trimethyl-1,4-naphthalindione (3.83%), α-Cadinol (3.17%), Bulnesol (2.65%) and 1,4-Dimethyl-7-(1-methylethyl) azulene (2.38%). The in vitro antibacterial activities of the essential oils were evaluated by the disc diffusion method. The inhibition zones against Staphylococcus aureus and Candida albicans were 23.7 and 23 mm. So the essential oil of L. nacusua showed potent antibacterial activity and potential high selectivity against S. aureus and C. albicans.     

Antioxidant activity of hydro distillation water residues from Rosmarinus officinalis L. leaves determined by DPPH assays

Rosemary (Rosmarinus officinalis L.) is a perennial herb with an intensive aromatic flavor. Its most important chemical constituents are essential oils (e.g., 1,8-cineole and camphor) and antioxidants (e.g., carnosic acid and rosmarinic acid). The common methods to extract the essential oil of rosemary are steam or hydro distillation. The aim of this work is to investigate the residual antioxidants after hydro distillation, especially rosmarinic acid and carnosic acid. For this purpose, the hydro distillation water residues were analyzed by HPLC-UV. Moreover, the influence of the extraction duration on the concentration of the antioxidants was investigated. Also, the residual amount of these compounds in the leaves was examined. The total antioxidant activity of the extracts and of the pure compounds was determined by DPPH assays. It is shown that after 2.5 h of hydro distillation the amount of rosmarinic acid and the antioxidant activity in the water residue reaches a maximum value. In addition, the yield and the quality of the essential oil were investigated to draw a comparison between steam and hydro distillations of Moroccan rosemary leaves.     

Application of PLE for the determination of essential oil components from Thymus vulgaris L

Essential plants, due to their long presence in human history, their status in culinary arts, their use in medicine and perfume manufacture, belong to frequently examined stock materials in scientific and industrial laboratories. Because of a large number of freshly cut, dried or frozen plant samples requiring the determination of essential oil amount and composition, a fast, safe, simple, efficient and highly automatic sample preparation method is needed.Five sample preparation methods (steam distillation, extraction in the Soxhlet apparatus, supercritical fluid extraction, solid phase microextraction and pressurized liquid extraction) used for the isolation of aroma-active components from Thymus vulgaris L. are compared in the paper. The methods are mainly discussed with regard to the recovery of components which typically exist in essential oil isolated by steam distillation.According to the obtained data, PLE is the most efficient sample preparation method in determining the essential oil from the thyme herb. Although co-extraction of non-volatile ingredients is the main drawback of this method, it is characterized by the highest yield of essential oil components and the shortest extraction time required. Moreover, the relative peak amounts of essential components revealed by PLE are comparable with those obtained by steam distillation, which is recognized as standard sample preparation method for the analysis of essential oils in aromatic plants.     

Static and dynamic superheated water extraction of essential oil components from Thymus vulgaris L.

Superheated water extraction (SWE) performed in both static and dynamic condition (S‐SWE and D‐SWE, respectively) was applied for the extraction of essential oil from Thymus vulgaris L. The influence of extraction pressure, temperature, time, and flow rate on the total yield of essential oil and the influence of extraction temperature on the extraction of some chosen components are discussed in the paper. The SWE extracts are related to PLE extracts with n‐hexane and essential oil obtained by steam distillation. The superheated water extraction in dynamic condition seems to be a feasible option for the extraction of essential oil components from T. vulgaris L.     

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.     

Chemical composition of the essential oils and headspace volatiles of Ferulago sylvatica (Besser) Reichenb. from Serbia

Abstract

Chemical composition of the headspace volatiles and essential oils isolated from different parts of Ferulago sylvatica was determined by GC and GC/MS analyses. The results showed that headspace volatiles obtained from the aerial parts and roots were similar regarding the number of identified compounds and main components. However, essential oils obtained from different plant organs showed significant differences in chemical composition. Myrcene was the most abundant component of the inflorescences and shoots volatiles, while α-pinene make up over 50% of the root volatiles. Only three components were identified in the root essential oil with 2,3,6-trimethyl benzaldehyde (92.7%) as the main component. In the shoots sample the terpenoid fractions represented 56% of the oil, unevenly distributed between monoterpenoids and sesquiterpenoids with germacrene D (32.5%) recognized as the main constituent. On the other hand, more than 94% of the inflorescences oils were monoterpenoids with myrcene as the most abundant contributor (29.2%).     

Chemical composition of the essential oil of Moluccella spinosa L. (Lamiaceae) collected wild in Sicily and its activity on microorganisms affecting historical textiles

In this study the chemical composition of the essential oil from aerial parts of Moluccella spinosa L. collected in Sicily was evaluated by GC and GC-MS. The main components of M. spinosa L. were α-pinene (26.6%), caryophyllene oxide (16.8%) and β-caryophyllene (8.6%). A comparison with other studied oils of genus Moluccella is made. Antibacterial and antifungal activities against some microorganisms infesting historical textiles were also determined.     

Sesquiterpene-rich volatile constituents of Ipomoea obscura (L.) Ker-Gawl.

The hydro-distilled essential oil from flowering aerial parts of Ipomoea obscura (L.) Ker-Gawl. (Convolvulaceae) was investigated by using gas chromatography equipped with a flame ionisation detector GC-FID and gas chromatography coupled with a mass spectrometry (GC/MS). Forty-two components, representing 97.1% of the total oil, were identified. The major constituents of the essential oil were α-bulnesene (23.8%), α-humulene (13.7%) and seychellene (11.2%). The other minor constituents were α-guaiene (8.3%), β-caryophyllene (7.1%), γ-terpinene (4.2%), hexadecanoic acid (3.0%) and β-elemene (2.7%). The oil was found to be rich in sesquiterpene hydrocarbon type constituents (78.4%).     

Chemical composition,antioxidant and antiproliferative activities of essential oil from rhizome and leaves of Curcuma mutabilis Škorničk., M. Sabu & Prasanthk., endemic to Western Ghats of India

Abstract

Hydro-distilled essential oils, from fresh rhizomes and leaves of Curcuma mutabilis ?korni?k., M.Sabu & Prasanthk., characterized by GC–MS revealed the presence of thirty three and twenty three compounds therein respectively. Whilst estrone methyl ether (3-Methoxyestra-1,3,5(10)-trien-17-one) was the major component in rhizome oil (47.35%), sesquiterpene hydrocarbons predominated as the major group (63.92%) in leaf oil with a higher preponderance of β-caryophyllene (25.48%), β-farnesene (19.47%) and α-humulene (11.01%). Weak antioxidant activities observed in these oils determined by DPPH and ABTS methods were apparently influenced both by the oil composition and the assay conditions. Rhizome oil showed higher antiproliferative activity than leaf oil against leukemic K562 (IC₅₀-6.8µg/mL) and colorectal HCT116 (IC₅₀-8.5µg/mL) cancer cell lines. This first report reveals composition and biological activities of essential oils from C. mutabilis.     

Essential oils of the leaves of grafts ofCitrus unshiu

The compositions of the essential oils obtained by steam distillation from the leaves of frost-resistant stocks of trifoliate orange (P. trifoliata (L.) Raf.) and Yunos-Yuzu citrus (Citrus ionos (Sieb.) and grafts of the mandarin orangeC. unshiu Marc —P. trifoliata +C. unshiu andC. ionos +C. unshiu — have been investigated with the aid of vacuum distillation, GLC, chromatography on an alumina column, and IR spectroscopy. The leaves were collected in the period of the flowering of the plants. The essential oils of grafts of the unshiu mandarin on trifoliate orange and Yunos-Yuzu citrus differed from one another with respect to the amounts of the components.Institute of Plant Biochemistry, Academy of Sciences of the Georgian SSR, Tbilisi, Batumi Botanical Garden, Academy of Sciences of the Georgian SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 607–610, September–October, 1984.     

Superheated water extraction, steam distillation and Soxhlet extraction of essential oils of Origanum onites

Superheated water extraction (SWE) at various temperatures (100, 125, 150 and 175°C), steam distillation, and Soxhlet extraction were compared in the extraction of essential oils from two samples of the plant Origanum onites, one cultivated, the other wild. C18 solid-phase extraction was used to elute the essential oils from the SWE aqueous extract. The compositions of the extracted essential oils obtained from all three methods were then characterized by comprehensive GC×GC/time-of-flight mass spectrometry (TOF/MS). The highest essential oil yields were obtained by using SWE at 150°C with a flow rate of 2 mL min^–1 and a pressure of 60 bar for 30 min: these were 3.76 and 4.11% for wild and cultivated O. onites samples, respectively, expressed as a percentage of 100 g of dry (leaf) matter. The yields obtained using SWE at 150°C were slightly higher than those from conventional methods. Steam distillation was performed for 3 h, and Soxhlet extraction was completed in 12 h. The major compounds found were borneol, terpinen-4-ol and carvacrol.