Analysis of the sesquiterpene fraction ofcitrusessential oils by using the off-line combination of high performance liquid chromatography and gas chromatography-based methods: a comparative study

Variations in Essential oils from South Siberian conifers of the Pinaceae family: new data towards identification and quality control

Conifer essential oils have been used for centuries in traditional medicine, and nowadays they are of special interest for official medicine, aromatherapy and perfumery. In the present work, comprehensive information is given on the composition of essential oils prepared from the twigs of the conifer trees of the pine family ( Pinaceae ): Abies sibirica Ledeb., Larix sibirica Ledeb., Picea obovata Ledeb., Pinus sibirica Du Tour, Pinus sylvestris L. A total of 50 samples of essential oils have been studied. The samples were prepared during vegetation stage in the time period 1998-2012 from the growing wild trees in the South part of the Western Siberia (Russian Federation) and neighboring territories of Republic of Kazakhstan within the area with geographical coordinates LAT 49.180012-57.908583 and LON 83.213217-91.258717 at elevation of 82-2070 m above sea level. All the essential oil samples were obtained from freshly collected plant raw material by steam distillation at atmospheric pressure in stainless steel apparatus, which had been specially designed for field research. All the chromatographic profiles were prepared from authentic samples whose voucher specimens are deposited at the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences (NS). The following information for each sample is provided: (1) date and location of the plant raw material collecting, indicating administrative areas and the exact geographic coordinates; (2) yield of essential oil, (3) chemical composition of the essential oil sample based on GC-MS experiments using full mass-spectra (EI, 70 eV) and linear retention indices of the components, (4) results of GC-FID quantification based on internal standards and response factors, (5) enantiomeric composition of the main components based on GC×GC experiments using the 2nd column with cyclodextrine-based chiral selector, (6) GC profile of the high-boiling fractions indicating the characteristic sesquiterpenoids. Therefore, this study provides reliable information about the variability and true composition of the Siberian conifer oils, and the experimental data given can serve as reference chromatographic profiles of volatile substances to solve the problems of quality, authenticity and safety.

In-Depth Qualitative Analysis of Lime Essential Oils Using the Off-Line Combination of Normal Phase High Performance Liquid Chromatography and Comprehensive Two-Dimensional Gas Chromatography-Quadrupole Mass Spectrometry

The present research is focused on the in-depth qualitative analysis of three types of lime essential oil (EO), viz., Key (A and B) and Persian, using the off-line combination of normal phase high performance liquid chromatography (NP-HPLC) and comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-QMS). The first analytical dimension (NP-HPLC) was exploited for the isolation of the hydrocarbon constituents from the oxygenated ones. Each fraction was then reduced in volume and analyzed using (cryogenic modulation) GC × GC-QMS. Peak assignment was carried out through the combined use of mass spectral database and linear retention index matching processes. The powerful four-dimensional technology enabled the separation and identification of a very high number (153) of lime essential oil volatile compounds.

Quali-quantitative characterization of the volatile constituents in Cordia verbenacea D.C. essential oil exploiting advanced chromatographic approaches and nuclear magnetic resonance analysis

Cordia verbenacea D.C. (Boraginaceae, Varronia curassavica Jacq. synonym) is a medicinal plant, native from Brazil, especially the leaves are used in folk medicine. The aim of this study was to extend the characterization of the volatile fraction of the essential oil obtained from this plant, by using GC-FID, GC-MS, and chiral GC. Moreover, to further clarify the composition of the volatile fraction, preparative multidimensional-GC (prep-MDGC) was used to collect unknown compounds, followed by NMR characterization. Specifically, the chemical characterization, both qualitative and quantitative, of the volatile fraction of the essential oil obtained from Cordia verbenacea cultivated in the Minas Gerais area (central area of Brazil) was investigated for the first time. The principal components from a quantitative point of view were α-pinene (25.32%; 24.48g/100g) and α-santalene (17.90%; 17.30g/100g), belonging to the terpenes family. Chiral-GC data are reported for the enantiomeric distribution of 7 different components. Last, to obtain the complete characterization of the essential oil constituents, prep-MDGC analysis was used to attain the isolation of two compounds, not present in the principal MS databases, which were unambiguously identified by NMR investigation as (E)-α-santalal and (E)-α-bergamotenal, reported for the first time in Cordia verbenacea essential oil.