The isotope ratio of monoterpene hydrocarbons in citrus essential oils of different origins was measured by ordinary high-resolution gas chromatography-mass spectrometry (HRGC-MS). The isotope ratio (Ir) was determined by the ratio of the isotope peak intensity (m/z 137) to the molecular mass peak intensity (m/z 136) of the monoterpene hydrocarbons. The accuracy of Ir was examined by measuring ...

The Pleistocene and recent distributions of the taxa are discussed. A new variety of Juniperus ashei, J. ashei Buch. var. ovata R. P. Adams is recognized from west Texas and northern Mexico. It differs from typical J. ashei in having whip leaf glands that are oval to elongate rather than hemispherical, smaller female cones, smaller seeds and more seeds per cone. In addition, the leaf oil of var...

The in vitro antibacterial and antioxidant activity of the essential oil and its two main components of Grammosciadium scabridum Boiss. (Apiaceae) growing wild in Iran, as well as the composition of its essential oil were studied. A total of 19 compounds representing 99.9% of the oil has been identified. Gamma-Terpinene (73.5%), p-cymene (14.2%) and (E)-beta-farnesene (5.3%) were characterized ...

Ips pini bark beetles use myrcene hydroxylases to produce the aggregation pheromone component, ipsdienol, from myrcene. The enantiomeric ratio of pheromonal ipsdienol is an important prezygotic mating isolation mechanism of I. pini and differs among geographically distinct populations. We explored the substrate and product ranges of myrcene hydroxylases (CYP9T2 and CYP9T3) from reproductively-i...

In the current study, the mosquito larvicidal activity of leaf essential oils and their constituents from two eucalyptus species (Eucalyptus camaldulensis and Eucalyptus urophylla) against two mosquito species, Aedes aegypti and Aedes albopictus, was investigated. In addition, the chemical compositions of the leaf essential oils were analyzed using gas chromatography-mass spectrometry. Results ...

The study was designed to determine the chemical composition and antimicrobial properties of the essential oil of Thymus vulgaris cultivated in Romania. The essential oil was isolated in a yield of 1.25% by steam distillation from the aerial part of the plant and subsequently analyzed by GC-MS. The major components were p-cymene (8.41%), γ-terpinene (30.90%) and thymol (47.59%). Its antimicrobi...

The essential oil was obtained from crushed seeds, extracted through Hydrodistillation method. The percentage yield of Carum roxburghianum was found 4.7% respectively. Physical properties i.e., colour, odour, specific gravity, solubility, refractive index, acid value and ester value were recorded according to the standard procedures. Chemical composition of essential oil of Carum roxburghianum ...

Fresh aerial parts of Angelica glauca, growing wild in Kashmir valley in higher Himalaya (Jammu and Kashmir, India), collected at flowering stage from different locations, on hydro-distillation provided a refreshing light pale coloured essential oil with characteristic floral woody flavour. The oil was found to be a complex mixture of mono- and sesquiterpenes and 34 compounds accounting for nea...

The seasonal variation in the chemical composition of the leaf essential oil of Zanthoxylum clava-herculis has been analyzed by GC-MS. Three individual trees were sampled four times during the course of the 2004 growing season. Notable differences were recorded in the essential oil yields from the three trees on the four collection dates; yields were highest in May and lowest in July. The leaf ...

Herein, we report on the use of nanopalladium on amino-functionalized siliceous mesocellular foam as an efficient heterogeneous catalyst for the transfer hydrogenation of nitroarenes to anilines. In all cases, the protocol proved to be highly selective favoring the formation of the desired aniline as the single product in high yields with short reaction times, when employing the naturally-occur...