No abstract

Essential oils from Lavandula genus and the obtained hybrids are widely used for different purposes such as perfume production in the cosmetic field and for its biological properties. This is the first study on the liquid and vapour phase of Lavandula × intermedia “Grosso” essential oil grown in the Lazio Region, Italy, investigated using headspace coupled to gas chromatography and mass spectrometry (HS-GC/MS). The results showed the most abundant components were linalool and linalyl acetate, followed by 1,8-cineole and terpinen-4-ol, while lavandulyl acetate and borneol were identified as minor compounds, maintaining the same proportion in both the liquid and vapour phase. Furthermore, we tested lavandin liquid and vapour phase essential oil on gram-negative bacteria (Escherichia coli, Acinetobacter bohemicus, and Pseudomonas fluorescens) and gram-positive bacteria (Bacillus cereus and Kocuria marina).

In this study, the chemical composition of the vapor and liquid phase of Pinus cembra L., Pinus mugo Turra, Picea abies L., and Abies Alba M. needles essential oils (EOs) was investigated by Headspace-Gas Chromatography/Mass Spectrometry (HS-GC/MS). In the examined EOs, a total of twenty-eight components were identified, most of which belong to the monoterpenes family. α-Pinene (16.6–44.0%), β-pinene (7.5–44.7%), limonene (9.5–32.5%), and γ-terpinene (0.3–19.7%) were the most abundant components of the liquid phase. Such major compounds were also detected in the vapor phase of all EOs, and α-pinene reached higher relative percentages than in the liquid phase. Then, both the liquid and vapor phases were evaluated in terms of antibacterial activity against three Gram-negative bacteria (Escherichia coli, Pseudomonas fluorescens, and Acinetobacter bohemicus) and two Gram-positive bacteria (Kocuria marina and Bacillus cereus) using a microwell dilution assay, disc diffusion assay, and vapor phase test. The lowest Minimum Inhibitory Concentration (MIC) (13.28 mg/mL) and Minimal Bactericidal Concentration (MBC) (26.56 mg/mL) values, which correspond to the highest antibacterial activities, were reported for P. abies EO against A. bohemicus and for A. alba EO against A. bohemicus and B. cereus. The vapor phase of all the tested EOs was more active than liquid phase, showing the inhibition halos from 41.00 ± 10.15 mm to 80.00 ± 0.00 mm for three bacterial strains (A. bohemicus, K. marina, and B. cereus). Furthermore, antioxidant activities were also investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays, and a concentration-dependent antioxidant capacity for all EOs was found. P. mugo EO showed the best antioxidant activity than the other Pinaceae EOs. The four Pinaceae EOs could be further investigated for their promising antibacterial and antioxidant properties, and, in particular, α-pinene seems to have interesting possibilities for use as a novel natural antibacterial agent.

The immobilization of ferrocene's amino derivatives onto carboxyl-functionalized multiwalled carbon nanotubes (MVVCNTs-COOH) electrodes has been carried out to test the ability of the ion reactive landing procedure to realize chemically modified electrodes. The ionic, species involved in the ion reactive landing procedure were structurally and energetically characterized by the joint application of collisionally induced dissociation mass spectrometry and theoretical calculations. Furthermore, the modified surface was analyzed by spectroscopic and voltammetric techniques and the electron mediation of the ferrocene derivatives demonstrated in the presence of laccase. Data obtained put in evidence a strong interaction between the landed molecules and the MWCNTs surface

Direct elemental fluorination of representative aromatic substrates, including PhH, PhCH3, PhF, PhCI, PhBr, PhN02, PhCN, and PhOCH3, has been investigated in inert solvents, e.g., CC13F and other fluorocarbons, over the temperature range - 154 to 40 OC. In order to achieve the necessary control of the extremely reactive electrophile, and to minimize unwanted modifications of the reaction environment, the fluorination has been carried out at extremely low rates and correspondingly low conversions, generally below 0.01%, using as a reagent gaseous mixtures of F2 highly diluted ( < I mol %) in N2 or Ar. The partial rate factors, calculated from a consistent set of relative reactivity and orientation data measured at -78 OC in CC13F, correlate smoothly with the u+ constants for all the substituents investigated, giving a p+ value of -2.45 for aromatic substitution by elemental fluorine with a correlation coefficient of 0.993. These results characterize F2 as a highly reactive, and correspondently unselective, reagent, and support a polar electrophilic substitution mechanism that is discussed and compared with other plausible fluorination pathways