Comparative GC-MS Analysis of Bay Leaf (Laurus nobilis L.) Essential Oils in Commercial Samples

Chemical composition of Laurus nobilis essential oils traded as spice and medicinal items was analyzed by gas chromatography-mass spectrometry. Sixty-four compounds accounting between 91–99% of the total oil was identified. Qualitative and quantitative differences were found among essential oils obtained from bay leaves used both for cooking and medicinal purposes. The oxygenated compounds were the principal fraction in all analyzed oils and consisted in oxygenated monoterpenes (73.13%), in medicinal essential oil and oxygenated monoterpenes (37.60 and 29.82%), oxygenated sesquiterpenes (15.98 and 22.99%), and phenylpropanoids (24.78 and 26.33%), respectively, in commercial food items. A high content of methyl eugenol (19 ± 4%; 21 ± 1%) and α-terpinyl acetate (18 ± 5%; 17 ± 7%) was found in commercial food items, whereas 1,8-cineole (51%) and α-terpinyl acetate (10%) were the main compounds in commercial pharmaceutical items.     

Isolation of volatile oil from thyme (Thymbra spicata) by steam distillation

The effects of steam flow rate (1.03 and 0.64 L/h), distillation time, and particle size (0.50, 1.00, 2.05 mm) of Thymbra spicata on essential oil yield and sequence of extraction of compounds were studied. A logarithmic model fitted well to experimental data. The composition of the essential oil obtained by steam distillation was investigated for whole leaves only since the grinding had an adverse effect on yield. The oil obtained was very rich with respect to its carvacrol content. For both steam flow rates, oxygenated monoterpenes were recovered the most rapidly. Using whole leaves (2.05 mm) and a higher steam flow rate (1.03 L/h) for 75 min of distillation was chosen as the optimum which gives the lowest amount of monoterpene hydrocarbons, the complete recovery of oxygenated compounds, and the highest yield in a shorter time. Yield was 1.57% at this optimum condition. The oil was composed of 53.1% oxygenated compounds, 25.7% monoterpene hydrocarbons, 4.4% sesquiterpenes, and 14.1% p-cymene.     

Terpene and Sesquiterpene Hydrocarbons in the Essential Oil from Fresh Celery

SUMMARY: The terpene and sesquiterpene hydrocarbons in celery essential oil that was recovered by two different methods were separated from the oxygen containing materials by column chromatography and analyzed by temperature-programmed gas chromatography. The essential oils were prepared from celery puree by a batch distillation procedure, and by vaporization in a Votator Turba-Film evaporator and rectification of the vapors in a packed distillation column. The terpenes α-pinene, β-pinene, myrcene, limonene, γ-terpinene and cymene; and the sesquiterpenes β-elemene, β-caryophyllene, α- and β-humulene and β-selinene were identified as constituents of the essential oils. The qualitative and quantitative relationships of the hydrocarbons between the two different oils were established and discussed.     

Influence of the process, season, and origin on volatile composition and antioxidant activity of Juniperus phoenicea L. leaves essential oils

Essential oils of Juniperus phoenicea L. leaves cultivated in 3 regions, Korbos, Matmata, and Tabarka of Tunisia were obtained by hydrodistillation (HD), steam distillation (SD), and Soxhlet (SH) extraction methods. The essential oils were analyzed and quantified by capillary gas chromatography using flame ionization detection (GC-FID) and mass spectrometry (GC-MS). The highest yield was observed in HD process (1.12%). Tabarka essential oil provided the best yield 0.79% compared to other regions. December month SD essential oil was the highest in oxygenated monoterpenes (52.7%). Nevertheless, SH essential oil showed a higher content in sesquitepenes hydrocarbons (64.5%). α-Terpinol (25.5%) was the main oxygenated component in Matmata juniper essential oil, extracted by SD. Moreover, the antioxidant activity of essential oils was evaluated using ABTS assays. The strongest antioxidant activity (IC(50) = 22.6 ± 0.7 mg/L) was obtained by the Matmata (October 2007) SD essential oil.     

Essential Oils of New Pigmented Citrus Hybrids: Citrus sinensis L. Osbeck x C clementina Hort. ex Tanaka

The chemical composition of the essential oils of 2 new pigmented Citrus hybrids (Omo‐6 and Omo‐12) was studied by gas chromatography‐mass spectrometry (GC‐MS). The hybrids were obtained by crossbreeding the orange Citrus sinensis (L.) Osbeck cultivar‘Moro’ and clementine Citrus clementina Hort. ex Tanaka cultivar‘Oroval’. Seventy‐eight components were fully characterized and grouped in five classes (monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpenes, aliphatic alcohols and ethers, and aliphatic aldehydes) for an easier comparison of the oils with parents and those of 2 previously analyzed hybrids (Omo‐15 and Omo‐31) from the same crossbreeding procedure.     

VARIATIONS IN ESSENTIAL OIL COMPOSITION DURING MATURATION OF CORIANDER (CORIANDRUM SATIVUM L.) FRUITS

The composition of volatile components of the essential oils extracted from fruits of coriander ( Coriandrum sativum L.) at four stages of maturity was studied by gas chromatography–flame ionization detector and gas chromatography-mass spectrometry. Essential oil yields showed marked increase during maturation process and 41 compounds were identified. Linalool was the main compound in all ripening stage amounting from 36.69 to 72.35%. Geranyl acetate (35.17%), β-caryophyllene (3.47%) and borneol (3.26%) were the main compounds at the first stage of maturity (immature fruits). At the second stage, geranyl acetate (8.21%), camphor (4.01%) and menthol (2.96%) were reported as the main constituents. In the third stage, geranyl acetate (20.66%), α-humulene (5.44%) and limonene (1.68%) were the main compounds. At the final stage of maturity (mature fruits), essential oil consist mainly on geranyl acetate (1.49%) and borneol (0.97%) in addition to linalool (72.35%). Additionally, accumulation of monoterpene alcohols was observed during maturation process of coriander fruit.

PRACTICAL APPLICATIONS

The chemical composition of the essential oil of coriander ( Coriandrum sativum L.) fruits is characterized by the occurrence of numerous components with great economical values. The oxygenated monoterpene and linalool were the most used ingredient in the cosmetic, perfume and food industries. On the other hand, the increasing market demands of the oxygenated components, widely present in this oil make it in the first rank of natural product. The formers were only obtained from the mature fruits. In this context, knowledge of their evolution during maturation process of the fruits seems to be a helpful tool for a better use of this economical potential.     

微波无溶剂萃取法提取野菊花精油工艺及成分分析

采用微波无溶剂萃取法（Solvent-free microwave extraction, SFME）分别提取野菊花鲜花精油和干花精油,对提取工艺进行了优化;并通过气相色谱-质谱联用技术（chromatograpy-mass spectrometry, GC-MS）分析两种精油化学成分,用峰面积归一法计算各组分相对含量。结果表明:野菊花鲜花精油的最佳提取条件为提取时间50 min,微波功率540 W,精油得率为鲜花重的0.1129%;干花精油的最佳提取条件为料液比1:5 g/mL,浸泡时间3 h,提取时间60 min,微波功率540 W,精油得率为干花重的0.1926%;经GC-MS分析,SFME提取野菊花鲜花精油的主要化学成分是单萜及单萜类含氧化合物,相对含量较多的化合物是乙酸桧酯（13.20%）、甲位侧柏酮（11.10%）、桧醇（9.70%）、菊醇（5.06%）、甲位水芹烯（3.87%）、荜澄茄油烯（3.78%）、桉叶油素（3.61%）、崖柏醇（3.37%）、2-侧柏烯（3.36%）。干花精油的主要化学成分是单萜含氧化合物及倍半萜,相对含量较多的化合物是菊醇（8.59%）、反式石竹烯（7.63%）、大根香叶烯（7.06%）、Α-合金欢烯（5.86%）、甲位侧柏酮（4.85%）、乙酸桧酯（4.34%）、乙酸菊醇酯（3.45%）、右旋樟脑（3.35%）。野菊花鲜花精油的含量比干花更高,单萜含氧化合物相对含量高于干花精油,更具有应用价值。     

Composition of the essential oils from leafy parts of the shoots,flowers and fruits of Eryngium amethystinum from Amiata Mount (Tuscany,Italy)

The essential oils obtained from the leafy parts of the shoots, inflorescences and fruits of Eryngium amethystinum (Apiaceae) from Italy have been studied. The essential oil from the inflorescences was characterised by methyl-derivatives of benzaldehyde (26.4%) and by some phenylpropanoids (3.0%) such as eugenol and (E)-methyl isoeugenol. The essential oil of leafy parts of the shoots showed a higher percentage of sesquiterpenes (31.3%) than monoterpenes (20.2%). The main differences between the two essential oils can be referred to α-pinene and germacrene D: the essential oil of the inflorescences contained much more α-pinene than the other one (25.6% vs. 11.8%), while the contrary is true for germacrene D (14.5% vs. 31.3%).     

A comparison of the peel oil components of Australian native lime (Microcitrus australe) and Mexican lime (Citrus aurantifolia Swingle)

The essential oil components extracted from the pericarp layer of two varieties of lime fruit, viz. Mexican lime (Citrus aurantifolia Swingle) and an Australian native lime (Microcitrus australe) have been analysed by gas chromatography/mass spectrometry. Thirty‐three components were identified in M australe and 34 in C aurantifolia. The compound types comprised monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpenes and coumarins. For the more volatile monoterpenoid compounds, the major component was limonene, with significant amounts of γ‐terpinene, β‐pinene, geranial, neral, neryl acetate and geranyl acetate. From an examination of the nature and contents of individual components, there was no indication that any one compound might be responsible for the predominant aroma impact. The possible contribution to aroma differences due to quantitative differences in the amounts of these components is discussed. However, sensory evaluation indicated that there was little or no difference between the aromas of the two oils. Copyright © 2004 Society of Chemical Industry     

Volatile constituents of leaf,stem and root oils of cinnamon (Cinnamomum zeylanicum)

Gas-chromatographic analysis of the volatile oils of the leaves, stem-bark and root-bark of commercial cinnamon (Cinnamomum zeylanicum), grown in Sri Lanka revealed interesting differences between them. All three oils possessed the same array of monoterpene hydrocarbons though in different proportions. The main constituents of leaf, bark and root oils are eugenol, cinnamaldehyde and camphor, respectively. Besides these, several other significant differences were observed. α-Ylangene, methyl and ethyl cinnamate in leaf oil, benzyl benzoate in bark oil and 4-terpinene-1-ol in root-bark oil are reported for the first time.     

Genetic improvement of Citrus fruits: The essential oil profiles in a Citrus limon backcross progeny derived from somatic hybridization

The peel essential oil profiles of an interspecific allotetraploid somatic hybrid, achieved by protoplast fusion of the ‘Valencia’ sweet orange (Citrus sinensis L. Osbeck) and ‘Femminello’ lemon (Citrus limon L. Burm), and three sexual hybrids obtained by back crosses between Femminello lemon and the allotetraploid somatic hybrid (Valencia + Femminello), have been studied by gas chromatography (GC) combined with a flame ionization detector (FID) and a mass spectrometry (MS). In total, 83 components were fully characterized and grouped in four classes (monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpenes, and others) for an easier comparison of all oils. A statistical treatment by linear discriminant analysis (LDA) of the compositional data from the allotetraploid hybrid and the three sexual hybrids show an intermediate essential oil profile with respect to those of both parents. The contribution of ‘Femminello’ lemon parent is in all cases predominant in the production of the volatile profiles of the new hybrids; however, a different behavior in the peel essential accumulation between the allotetrapolid hybrid and the three hybrids is observed.     

Effect of extraction techniques on the chemical composition and antioxidant activity of Eucalyptus camaldulensis var. brevirostris leaf oils

 The volatile oil compositions of Eucalyptus camaldulensis var. brevirostris leaves obtained by hydrodistillation (HD) and supercritical fluid extraction methods (SFE) were analysed qualitatively and quantitatively by GLC-MS. Ninety different components were separated and most of them identified. In both extracts the main constituents were found to be β-phellandrene (8.94 and 4.09%), p–cymene (24.01 and 10.61%), cryptone (12.71 and 9.82%) and spathulenol (14.43 and 13.14%). The yield of the monoterpene hydrocarbons in HD oil (0.288 g/100 g fresh leaves) was slightly higher compared with that in the SFE extract (0.242 g/100 g fresh leaves). The SFE extract possessed higher concentrations of the sesquiterpenes, light oxygenated compounds and heavy oxygenated compounds than the HD oil. The relationship between the antioxidant activity and chemical composition of the extracted oils was investigated. The significant amounts of p–cymen-7-ol and thymol are responsible for the antioxidative activity of both extracts. The concentration of both compounds, but especially that of p–cymen-7-ol (2.25%), is higher in the SFE extract. This corresponds with the higher antioxidative activity of the SFE compared with the HD extract. p–Cymen-7-ol, a compound newly identified in leaves of Eucalyptus species, exhibited superior antioxidant activity in comparison with that of butylated hydroxyanisole.     

Effect of extraction techniques on the chemical composition and antioxidant activity of Eucalyptus camaldulensis var. brevirostris leaf oils

 The volatile oil compositions of Eucalyptus camaldulensis var. brevirostris leaves obtained by hydrodistillation (HD) and supercritical fluid extraction methods (SFE) were analysed qualitatively and quantitatively by GLC-MS. Ninety different components were separated and most of them identified. In both extracts the main constituents were found to be β-phellandrene (8.94 and 4.09%), p–cymene (24.01 and 10.61%), cryptone (12.71 and 9.82%) and spathulenol (14.43 and 13.14%). The yield of the monoterpene hydrocarbons in HD oil (0.288 g/100 g fresh leaves) was slightly higher compared with that in the SFE extract (0.242 g/100 g fresh leaves). The SFE extract possessed higher concentrations of the sesquiterpenes, light oxygenated compounds and heavy oxygenated compounds than the HD oil. The relationship between the antioxidant activity and chemical composition of the extracted oils was investigated. The significant amounts of p–cymen-7-ol and thymol are responsible for the antioxidative activity of both extracts. The concentration of both compounds, but especially that of p–cymen-7-ol (2.25%), is higher in the SFE extract. This corresponds with the higher antioxidative activity of the SFE compared with the HD extract. p–Cymen-7-ol, a compound newly identified in leaves of Eucalyptus species, exhibited superior antioxidant activity in comparison with that of butylated hydroxyanisole. Received: 30 April 1998     

Essential oil of nutmeg pericarp

The composition of the volatile oil extracted by hydro-distillation from nutmeg pericarp and the component retention indices were determined by gas chromatography–mass spectrometry GC-MS The oil contains 16 monoterpenes (60%), nine monoterpene alcohols (29%), eight aromatic ethers (7%), three sesquiterpenes (1%), six esters (1%) and eight other minor components. The components are similar to those in nutmeg and mace oils but differ substantially in concentrations. The sabinene, myristicin and safrole concentrations are much lower while the terpinen-4-ol and α-terpineol contents are much higher than in nutmeg and mace oils. © 1999 Society of Chemical Industry     

鼠尾草(Salvia officinalis L.)不同组织精油组分差异比较

利用甲基叔丁醚法结合气相色谱-质谱联用技术比较鼠尾草花、叶片及茎精油的挥发性组分差异。结果表明:鼠尾草不同器官中共检测到4种单萜、17种倍半萜、6种单萜衍生物、2种倍半萜衍生物及2种酯类化合物共31种挥发性物质;不同器官的挥发性组分不尽相同,花器官中的挥发性组分最多为31种化合物;挥发性物质含量最高的是叶片,达到2 334.48 ng/g;吉玛烯、可巴烯、石竹烯及乙酸芳樟酯是鼠尾草不同器官中含量较高的挥发性组分,但其对不同器官挥发性精油的贡献率亦不同。     

Essential oil composition of Salvia miltiorrhiza flower

Hydrodistillation of the flower of seven populations of Salvia miltiorrhiza Bge. collected in different locations in China afforded a pale yellowish oil in a yield of approximately 0.2%. A total of 82 compounds were identified across all the samples, accounting for 98–100% of the total compositions of each sample. Components were mainly monoterpenes, sesquiterpenes, fatty acids and alkanes. GC and GC–MS analysis indicated that the predominant components of the essential oils are β-caryophyllene (12.2–31.7%), β-caryophyllene oxide (1.4–11.6%), α-caryophyllene (4.8–10.6%), cadinadiene (7.4–29.3%), and hexadecanoic acid (3.9–18.8%).     

Volatile constituents of the essential oil of Monodora myristica (Gaertn) dunal

The essential oil of Monodora myristica was obtained by steam distillation with a yield of 45-6 g kg^?1. The composition of the oil was analysed by gas chromatography and gas chromatography-mass spectrometry. The oil was found to contain 75% monoterpene hydrocarbons; the major compounds being α-phellandrene (50–4%), α-pinene (5–5%) and myrcene (4–35%). There were also a few sesquiterpene hydrocarbons (3%) and oxygenated compounds such as germacrcne-D-4-ol (9–5%). Germacrene-D-4-ol, α-pinene, Δ²-carene, β-caryophyllene, valencene. γ-muurolol and carvacryl acetate have not previously been reported in M myristica.     

BIOCHEMICAL CHARACTERIZATION OF BORAGE (BORAGO OFFICINALIS L.) SEEDS

Gas chromatography–mass spectrometry analysis of seed Borago officinalis essential oil (EO) revealed the presence of 16 volatile components. β-Caryophyllene (26%) and p-cymene-8-ol (19.7%) represented the major components, while nonadecane (0.7%) and hexanol (0.7%) were the minor ones. The EO composition was characterized by higher abundance of oxygenated monoterpenes (27.7%), followed by sesquiterpenes (26%). Fatty acid composition showed the predominance of linoleic (35.4%), oleic (24.2%) and γ-linolenic (20.4%) acids. Polyphenols were analyzed by reversed-phase high-performance liquid chromatography after acid hydrolysis of phenolic acid esters. Six phenolic acids were identified in seed extract and rosmarinic acid was the predominant one with 1.65 mg/g dry matter weight equivalent to 33% of total phenolic acids.

PRACTICAL APPLICATIONS

Borage ( Borago officinalis L.) is of great interest because of its medicinal and nutritional properties. In fact, thanks to its characteristic composition in fatty acids, particularly high levels of gamma-linolenic acid in its seed oil, borage has gained importance. The potent consumers of this medicinal plant are hypertensive and hypercholesterolemic people. Borage consumption is also recommended for people suffering from rheumatism and eczema.
Unfortunately, the knowledge about antioxidative/antiradical properties of borage is very scanty. So, recently, an extensive investigation was focused on the antioxidant properties of borage extracts. These extracts showed excellent antioxidant properties and their effects were attributed to their phenolic constituents. These antioxidants can be concentrated, either as crude extracts or individual phenolic compounds, to be used in highly unsaturated oils such as marine oils. Furthermore, borage consumption has been reported as a possible gastric cancer protective factor.     

Comparative evaluation of the antibacterial activities of the essential oils of Rosmarinus officinalis L. obtained by hydrodistillation and solvent free microwave extraction methods

Rosmarinus officinalis L. is a perennial herb that belongs to the Lamiaceae family. It is used as a food flavouring agent, and well known medicinally for its powerful antimutagenic, antibacterial and chemopreventive properties. Essential oils were obtained from this plant by hydrodistillation (HD) and solvent free microwave extraction (SFME). GC–MS analyses of the oils revealed the presence of 24 and 21 compounds in the essential oils obtained through HD and SFME, respectively. The total yield of the volatile fractions obtained through HD and SFME was 0.31% and 0.39%, respectively. Higher amounts of oxygenated monoterpenes such as borneol, camphor, terpene-4-ol, linalool, α-terpeneol (28.6%) were present in the oil of SFME in comparison with HD (26.98%). However, HD oil contained more monoterpene hydrocarbons such as α-pinene, camphene, β-pinene, myrcene, α-phellanderene, 1,8-cineole, trans β-ocimene, γ-terpenene, and cis sabinene hydrate (32.95%) than SFME extracted oil (25.77%). The essential oils obtained using the two methods of extraction were active against all the bacteria tested at a concentration of 10 mg ml⁻¹. Minimum inhibitory concentration (MIC) values for all the susceptible bacteria ranged between 0.23 mg ml⁻¹ and 7.5 mg ml^−1.     

Qualitative and quantitative changes in the essential oil of Laurus nobilis L. leaves as affected by different drying methods

The effect of six different drying methods on the content and chemical composition of the essential oil of Laurus nobilis L. leaves was studied. The essential oils from fresh and dried samples were isolated by hydrodistillation in a Clevenger apparatus and analysed by gas chromatography–mass spectrometry (GC–MS). Results showed that air drying at ambient temperature and infrared drying at 45 °C increased significantly the essential oil content. Forty-seven components were determined in essential oils, which were mostly oxygenated monoterpenes. This class of compounds is not significantly affected by the method of drying except for air drying at ambient temperature. The main components 1,8-cineole, methyl eugenol, terpinen-4-ol, linalool and eugenol showed significant variations with drying methods. The concentrations of these compounds increased significantly in the case of air drying at ambient temperature. These results allowed considering this method of drying as the method that produced the best results in terms of essential oil and bioactive compounds contents.