Principal Components Of Essential Oil Research Articles

A Chromosome-Level Genome of the Camphor Tree and the Underlying Genetic and Climatic Factors for Its Top-Geoherbalism.

Camphor tree [Cinnamomum camphora (L.) J. Presl], a species in the magnoliid family Lauraceae, is known for its rich volatile oils and is used as a medical cardiotonic and as a scent in many perfumed hygiene products. Here, we present a high-quality chromosome-scale genome of C. camphora with a scaffold N50 of 64.34 Mb and an assembled genome size of 755.41 Mb. Phylogenetic inference revealed that the magnoliids are a sister group to the clade of eudicots and monocots. Comparative genomic analyses identified two rounds of ancient whole-genome duplication (WGD). Tandem duplicated genes exhibited a higher evolutionary rate, a more recent evolutionary history and a more clustered distribution on chromosomes, contributing to the production of secondary metabolites, especially monoterpenes and sesquiterpenes, which are the principal essential oil components. Three-dimensional analyses of the volatile metabolites, gene expression and climate data of samples with the same genotype grown in different locations showed that low temperature and low precipitation during the cold season modulate the expression of genes in the terpenoid biosynthesis pathways, especially TPS genes, which facilitates the accumulation of volatile compounds. Our study lays a theoretical foundation for policy-making regarding the agroforestry applications of camphor tree.

Diversity in chemical compositions of essential oil of myrtle leaves from various natural habitats in south and southwest Iran

Myrtle, Myrtus communis L. (Myrtaceae), an evergreen shrub also known as wild myrtle, has a history of use as a culinary and medicinal plant. To determine the diversity within the species, plant leaves of myrtle were collected in 12 natural habitats in Iran for investigation of chemical constituents in the essential oil. Extraction of the essential oils produced yields ranging from 0.7 to 1.5 mL per 100 g dry tissue. An analysis of the oils by GC and GC/MS revealed 40 compounds, constituting 90.1–99.9 % of the essential oils. Chemical constituents varied with the site of sample origin, although the principal essential oil components from all populations, were α-pinene (17.5–37.1 %), 1,8-cineole (9.9–29.8 %), linalool (7.0–23.1 %), and α-terpineol (5.3–8.3 %). Limonene (tr, 22.7 %) was a major constituent in three populations. Characterized chemotypes included Chemotype I: α-pinene/1,8-cineole/linalool, Chemotype II: α-pinene/linalool, Chemotype III: α-pinene/1,8-cineole, and Chemotype IV: α-pinene/1,8-cineole/limonene. The main source of variability in chemical composition and oil yield appeared to be differences in environmental conditions and chemotypes as plant populations collected from close geographical areas could be classified in a cluster.

Comparative Chemical Composition and Antioxidant Properties of the Essential Oils and Aromatic Water from Teucrium persicum Boiss.

The essential oils and aromatic water, known as Arak in traditional Iranian medicine, comes from the aerial part of Teucrium persicum Boiss., which is grown in Fars Province located in Iran. The samples were collected in summer and the oils and aromatic water were obtained through steam distillation. The chemical composition of the oils was analyzed using GC-MS. An analysis of the chemical profile of the isolated oils revealed the presence of more than 80 compounds, mainly oxygenated monoterpenes and sesquiterpene hydrocarbons. The principal components of essential oil were α-cadinene (9.7%), 1,4-cadinadiene (9.2%) and α-terpinyl acetate (7.9%). The major constituents in the Arak were determined to be linalool (10.4%), α-cadinene (7.5%) and γ-terpineol (7.3%). Most of the compounds identified from different oils were similar, but their amounts differed. The oil revealed a higher content of total phenolics than the Arak (1.71 ± 0.12 mg GAE/g DW and 1.36 ± 0.11 mg GAE/g DW, respectively). The antioxidant activity of the oils was calculated by using a ferric reducing antioxidant power assay (FRAP), DPPH radical scavenging activity, and a reducing power assay (RP). The FRAP value points to a considerably higher reducing power of essential oil (220 ± 7.2 µmol Fe(2+)/g DW) compared to that of Arak (113 ± 5.4 µmol Fe(2+)/g DW). Essential oil exhibited higher radical scavenging potential (IC50 = 0.29 mg/mL) than Arak (IC50 = 4.19 mg/mL). The reducing power of essential oil (51.7 ± 4.3 µg BHA/g DW) was higher than that of Arak (34.1 ± 2.7 µg BHA/g DW). The studied essential oils showed good antioxidant activities, which were higher than those of Arak.

HUMIC SUBSTANCES AND MOISTURE CONTENT IN THE PRODUCTION OF BIOMASS AND BIOACTIVE CONSTITUENTS OF Th ymus vulgaris L.

Thyme (Thymus vulgaris L.) is an aromatic and medicinal plant with antioxidant, antimicrobial and antinfungical properties that have attracted the interest of pharmacological and food industries. Humic substances (HS) are a natural product that has shown beneficial effects on soil and on plant growth. These positive effects are explained by the direct interaction of HS with physiological processes. But it is unknown their effect on the composition of the thyme bioactive constituents. To test the effect of humic substances, seeds of T. vulgaris were germinated and grown at different rates of HS (100, 200, 300 and 400 mg L-1). Th yme plants were also grown at three levels of moisture (20, 40 and 60 % of field capacity). At harvest plant height and shoot fresh and dry weight were measured. Bioactive constituents were determined in terms of yield and principal components of essential oil (by distillation in Clevenger apparatus and gas chromatography). Antioxidant activity, total phenolic and flavonoid content were determined with spectrophotometric techniques. Morphological variables, except for shoot fresh weight, showed signifi cant differences (P ≤ 0.05) among treatments. The essential oil yield and composition, as well as antioxidant activity and total phenolic and flavonoid contents, were higher at the highest levels of HS and substrate moisture.

Chemical composition and antimicrobial activity of essential oil from seeds of Anethum graveolens growing in Uzbekistan

We have previously studied the chemical composition of essential oil (EO) from seeds of Anethum graveolens from Xinjiang Autonomous District in the PRC [1]. The component composition of essential oils is known to depend on the habitat. It seemed interesting to compare the composition and biological activity of EO from dill seeds growing in China and Uzbekistan. We used GC—MS to establish the structures of the isolated compounds. EO from seeds of A. graveolens (2007 harvest) that were collected in Tashkent Oblast was isolated by steam distillation in 4.2% yield. The chemical composition of the EO was studied using a Perkin—Elmer Turbo GC—MS. The component content of the oil was calculated using areas of GC peaks of total ion current without correlation coefficients. EO components were identified by comparing retention times and mass spectra of the component obtained in mass scanning mode and by using mass-spectral library data for standard oil components and pure compounds. A total of 22 chemical compounds was identified in EO of A. graveolens seeds growing in Uzbekistan. Table 1 lists the chemical composition of the EO. The principal EO components from dill seed growing in Uzbekistan were carvone (73.61%), limonene (14.69), cis-dihydrocarvone (5.87), diplaniol (1-allyl-2,5-dimethoxy-3,4-methylenedioxybenzene) (2.16), and 1,2-diethoxyethane (1.43%), which together made up 99.2% of the total EO component composition. The principal components of EO from dill seed growing in China were n-pentacosane (27.96%), dioctylester of 1,2-phenyldicarboxylic acid (25.10), octacosane (13.81), tricosane (9.14), and n-nonacosane (6.85%) [1]. A comparison of our data with that obtained earlier indicated that both the qualitative and quantitative composition of the principal EO components of A. graveolens growing in different geographic zones differed considerably. The high content in the studied EO of carvone, which is widely used as a growth inhibitor of bacteria [2-4] and certain fungi [5] and as a repellent [6] is noteworthy. Both S-(+)-carvone and R-(-)-carvone are used in the food industry to produce flavors [4] and in agriculture. For example, S-(+)-carvone is used in the Netherlands to prevent premature sprouting of potato tubers and tulip bulbs during storage [7, 8]. Carvone is an available and inexpensive reagent for organic synthesis in both enantiomeric forms. This makes it attractive for asymmetric synthesis of natural compounds [9]. Antimicrobial activity of EO fractions toward Candida albican and Staphylococcus aureus was estimated using the Barry method to determine the minimal inhibiting concentration (MIC) [10]. Growth of microorganisms decreased markedly upon addition of EO to nutrient medium. The experimental results are given below: