Seasonal variation in the essential oil from Varronia curassavica jacq. accessions / Variación estacional en el aceite esencial de accesiones de Varronia curassavica Jacq

Varronia curassavica has anti-inflammatory properties because of the terpenes, α-humulene and ß-caryophyllene, present in the essential oil. The objective of this study was to evaluate the influence of seasonality on the essential oil of V. curassavica accessions. Leaves from six accessions were collected from the Germplasm Bank of the Federal University of Minas Gerais over 12 months. Correlations between the essential oil content and meteorological factors were determined. Gas chromatography analysis coupled with mass spectrometry was conducted to determine the chemical composition of the essential oil. The content and chemical composition of the oil varied throughout the year. Relative humidity was correlated with accessions ICA-VC2 (-0.64) and ICA-VC4 (0.68). ß-bourbonene, ß-elemene, spathulenol, germacrene, caryophyllene oxide, α-humulene, and ß-caryophyllene occurred in all accessions. Accession ICA-VC3 exhibited lower variation (22.17%), higher average (0.97%) essential oil, and maintained an average abundance of α-humulene greater than 2.6%, which is the amount necessary for phytotherapeutics.

Varronia curassavica tiene propiedades antiinflamatorias debido a los terpenos, α-humuleno y ß-cariofileno, presentes en el aceite esencial. El objetivo de este estudio fue evaluar la influencia de la estacionalidad en el aceite esencial de las accesiones de V. curassavica. Se recolectaron hojas de seis accesiones del Banco de Germoplasma de la Universidad Federal de Minas Gerais durante 12 meses. Se determinaron las correlaciones entre el contenido de aceite esencial y los factores meteorológicos. Se realizó un análisis de cromatografía de gases junto con espectrometría de masas para determinar la composición química del aceite esencial. El contenido y la composición química del aceite varió a lo largo del año. La humedad relativa se correlacionó con las accesiones ICA-VC2 (-0,64) e ICA-VC4 (0,68). En todas las accesiones aparecieron ß-bourboneno, ß-elemeno, espatulenol, germacreno, óxido de cariofileno, α-humuleno y ß-cariofileno. La accesión ICA-VC3 mostró una menor variación (22,17%), un promedio más alto (0,97%) de aceite esencial y mantuvo una abundancia media de α-humuleno superior al 2,6%, que es la cantidad necesaria para los fitoterápicos.

Chemical investigation and biological activities of the essential oil of Knema kunstleri Warb. from Malaysia.

The chemical composition of the essential oil of Knema kunstleri Warb. (Myristicaceae) was investigated for the first time. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 36 components were identified in the essential oil, which made up 91.7% of the total oil. The essential oil is composed mainly of ß-caryophyllene (23.2%), bicyclogermacrene (9.6%), δ-cadinene (7.3%), α-humulene (5.7%), and germacrene D (4.3%). The essential oil showed moderate activity towards DPPH free-radical scavenging and lipoxygenase inhibition. To the best of our knowledge, this is the first study of the composition and bioactivities of the essential oil report concerning the genus Knema.

Chemical composition of essential oils from the underground parts of Glycyrrhiza echinata L. accessions growing wild in Northern Iran.

Glycyrrhiza echinata L. is a perennial plant of considerable commercial importance in medicine, pharmaceuticals, cosmetics, and tobacco industries and the production of food additives as flavoring and sweetening agent. This study, variation on composition and yield of essential oil from the underground parts of five accessions of G. echinata growing wild in northern Iran was investigated. Results showed high variability for the main constituents of essential oil among accessions of G. echinata. The presence of α-pinene and myrcene in two accessions suggests that these volatiles could serve as chemotaxonomic markers and also might be considered as potentially relevant for taste. The presence of ß-caryophyllene and α- caryophyllene in three accessions could be strong potential for being used in medical applications (anticancer and analgesic properties). Generally, the essential oils from G. echinata and other species could be very competitive targets for phytochemical and food studies.

Influence of pre-drying storage time on essential oil components in dried hops (Humulus lupulus L.).

BACKGROUND: It is well known that duration of pre-drying storage impacts on hop quality. However, little knowledge exists regarding its actual effects on valuable hop components. To investigate these effects, fresh hop cones were stored for 5 or 24 h and dried for 210 min at 65 °C thereafter. Furthermore, to understand the effect of freezing hop cones on the essential oil content, both fresh and stored samples were frozen before and after drying. RESULTS: The results from gas chromatography analysis show an increase in linalool, ß-caryophyllene, humulene, geraniol content and decrease in myrcene content dependent on the period of storage. Total colour difference ΔE values of 4.61 and 5.27 were obtained for fresh and stored hops respectively, indicating discoloration of hops during storage. Modelling of moisture curves revealed the Wang and Singh model to be suitable, with R adj 2 values of 0.978 and 0.989 and root-mean-square error values of 0.037 and 0.019 for fresh and stored hops respectively. CONCLUSION: The results from this study provide an in-depth understanding on the changes occurring within the hop cones both during storage and drying and will further help hop processors optimize their storage times.

GC-MS analysis of the volatile constituents of Orthosiphon pallidus Royle, ex Benth.

The hydro-distilled essential oil from aerial parts of Orthosiphon pallidus Royle, ex Benth (Lamiaceae) was investigated by using gas chromatography equipped with a flame ionisation detector (GC-FID) and gas chromatography coupled with a mass spectrometry (GC-MS). Fifty-two compounds, representing 98.4% of the total oil constituents, were identified. The major constituents were ß-caryophyllene (17.4%) and 7-epi-α-selinene (15.2%). The other minor constituents were terpinolene (6.9%), ß-pinene (6.8%), ß-elemene (5.1%), α-humulene (4.9%), α-copaene (4.8%), epi-cubebol (4.5%) and zonarene (3.9%). The oil was found to be rich in sesquiterpene hydrocarbon type constituents. Lamiaceae[Formula: see text].

Biological properties and chemical composition of essential oil from Nectandra megapotamica (Spreng.) Mez. leaves (Lauraceae).

Nectandra megapotamica is a tree species that naturally occurs in the Atlantic Forest, Brazil. This paper aims to investigate the chemical composition and in vitro antibacterial, antileishmanial and antiproliferative activities of essential oil from N. megapotamica leaves (NM-EO). It displayed high antibacterial activity against Streptococcus mutans, S. sobrinus, Prevotella nigrescens and Bacteroides fragilis. NM-EO also exhibited high antileishmanial activity against promastigote forms of Leishmania amazonensis. Its antiproliferative activity was evaluated against the following cells: GM07429A (normal cell), MCF-7 (human breast adenocarcinoma), HeLa (human cervical adenocarcinoma) and M059J (human glioblastoma). Its major components, which were determined by GC-FID and GC-MS, were α-bisabolol (13.7%), bicyclogermacrene (10.9%), (E,E)-farnesene (10.6%), Z-caryophyllene (9.5%) and (E)-ß-farnesene (7.0%). These results suggest that N. megapotamica, a Brazilian plant, shows initial evidence of a new and alternative source of substances of medicinal interest.

Two new eudesman-4α-ol epoxides from the stem essential oil of Laggera pterodonta from Côte d'Ivoire.

The investigation of the stem essential oil of Laggera pterodonta (DC.) Sch. Bip. ex Oliv. (Asteraceae) from Côte d'Ivoire was carried out, using a combination of chromatographic (GC-RI, CC, pc-GC) and spectroscopic (GC-MS, 13C NMR) techniques. This study led to the identification of fifty constituents of which two new natural compounds 7ß,11ß-epoxy-eudesman-4α-ol and 7α,11α-epoxy-eudesman-4α-ol. Their structures were elucidated by 1 D and 2 D NMR spectroscopy after pc-GC purifying. Finally, 98.9% of the whole composition of the oil was identified with a high amount of 2,5-dimethoxy-p-cymene (78.9%). The other significant components were α-humulene (6.2%), (E)-ß-caryophyllene (1.7%), thymyl methyl oxide (1.7%), α-phellandrene (1.5%), p-cymene (1.2%), (3αH,4ßH,6αH,1αMe)-1,6-epoxy-3-hydroxycarvotanacetone angelic acid ester (1.1%) and 10-epi-γ-eudesmol (1.0%).

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

Hydro-distilled essential oils, from fresh rhizomes and leaves of Curcuma mutabilis Skornick., 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 ß-caryophyllene (25.48%), ß-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.

Male-Produced Aggregation Pheromone of the Sloe Bug, Dolycoris baccarum L. (Hemiptera: Heteroptera: Pentatomidae).

The sloe bug, Dolycoris baccarum L. (Hemiptera: Heteroptera: Pentatomidae), is a Palearctic species and an important polyphagous pest. Previous studies have reported that male D. baccarum produce an aggregation pheromone, to which conspecific adults of both sexes respond. We used solid-phase microextraction (SPME) to collect volatiles released by sexually mature virgin males and females, and identified potential components of the male-produced aggregation pheromone. Analysis of the SPME samples by gas chromatography-mass spectrometry (GC-MS) revealed three male-specific components, α-bisabolol, trans-α-bergamotene, and ß-bisabolene, at a ratio of 100:10:3. A field trapping experiment showed that (±)-α-bisabolol alone attracted D. baccarum adults, and it was synergized by trans-α-bergamotene, but not (S)-ß-bisabolene. However, neither trans-α-bergamotene nor (S)-ß-bisabolene was attractive individually. A binary blend of (±)-α-bisabolol and trans-α-bergamotene in a 10:1 ratio was less attractive than caged live males, suggesting that further study is necessary to determine the absolute configuration or steroisomeric composition of the natural pheromone components. This is the first report of α-bisabolol and trans-α-bergamotene as semiochemicals among Pentatomidae, and the first to identify α-bisabolol from insects.

Effect of pressure variation on the efficiency of supercritical fluid extraction of wild carrot (Daucus carota subsp. maritimus) extracts.

The present study was conducted to check the comparative qualities of essential oils prepared by hydrodistillation (HD) and supercritical fluid techniques. It constitutes the first attempt to investigate the chemical composition of Daucus carota subsp. maritimus extracts using supercritical fluid technology (SFE) as an environmentally clean innovative method of extraction. The effect of pressure on the nature of extractable substances from wild carrot has been performed at a constant temperature of 50 °C and two different pressures (100 and 300 bar). The experimental results showed that pressure had a significant enhancing effect on the fluid transport properties and therefore on yield values. The extraction yield increases from 1.167 to 2.986% while increasing pressure. The chemical compositions of the essential oils prepared by HD and SFE were analyzed on the basis of gas chromatography-mass spectroscopy (GC-MS). Thus, we noticed that all analyzed samples were enriched in geranyl acetate and ß­bisabolene, and that the quantities of different identified substances were extremely sensitive to the extraction method and to the pressure variation in case of SFE.