Search results for "COMPOUND"
showing 10 items of 35174 documents
Influence of harvesting time on composition of the essential oil of Thymus capitatus (L.) Hoffmanns. & Link. growing wild in northern Sicily and its …
2019
One of the main factors affecting historical art crafts material is the biodeterioration performed by bacteria and fungi, in archives, museums or private collections. Several microorganisms cause degradation to the natural organic material such as fibers, woods, and dyes as well as to stone objects. These alterations produce deterioration of physical, chemical, mechanical and esthetic properties. Consequently, in this publication, we report the high antibacterial and antifungal activities of wild thyme essential oil, oil that can be used as an alternative natural tool in the fight against microorganisms affecting historical art crafts.Essential oil of the Thymus capitatus growing wild in no…
Statistical analyses on the essential oil of italian coriander (coriandrum sativum L.) fruits of different ages and origins
2002
Thirty-one samples of Coriandrum sativum L. fruits, of different origin, year of cultivation (harvest) and crop management systems were subjected to volatile component analysis by combining Head Space Solid Phase Microextraction (HS-SPME) with GC/MS. In order to determine the importance of the major sources of volatile variability, some statistical analyses, including Cluster Analysis (CA) and Principal Component Analysis (PCA), were performed on the obtained data. The compounds, which gave the main contribution to the partition and classification of the original data, were α-pinene, p-cymene, γ-terpinene and linalool. The age of the fruits, which ranged from 1–16 years, seemed to generate …
Preparation of a Series of “Ru(p-cymene)” Complexes with Different N-Heterocyclic Carbene Ligands for the Catalytic β-Alkylation of Secondary Alcohol…
2008
A series of five different “(p-cymene)Ru(NHC)” complexes (NHC = imidazolin-2-ylidene, imidazolin-4-ylidene, and pyrazolin-3-ylidene) have been obtained and fully characterized. The crystal structure of two of the new complexes has been determined by X-ray diffraction methods. All five complexes have been tested in the catalytic β-alkylation of secondary alcohols with primary alcohols and the dimerization of phenylacetylene, showing an excellent activity in both processes. A clear improvement on the catalytic activity of the complexes is observed when the more basic NHC ligands are used. The pyrazolylidene-Ru complex lies among the best catalysts for the β-alkylation of secondary alcohols re…
Chemical composition and antimicrobial activity of the essential oil from aerial parts of Micromeria fruticulosa (Bertol.) Grande (Lamiaceae) growing…
2007
The essential oil of aerial parts of Micromeria fruticulosa (Lamiaceae) growing wild in Southern Italy was obtained by hydrodistillation and analysed by GC and GC–MS. Sixty-one compounds, representing 91.3% of the oil, were identified. The major components were γ-terpinene (14.5%), β-caryophyllene (12.6%), p-cymene (8.9%), α-pinene (8.2%) and β-bisabolene (7.2%). The essential oil showed action mainly against Gram-positive bacteria. Copyright © 2007 John Wiley & Sons, Ltd.
[60]Fullerene l -Amino Acids and Peptides: Synthesis under Phase-Transfer Catalysis Using a Phosphine–Borane Linker. Electrochemical Behavior
2017
International audience; A new method to link amino acid and peptide derivatives to [60]fullerene is described. It uses hydrophosphination with a secondary phosphine borane. First, the stereoselective synthesis of secondary phosphine borane amino acid derivatives was achieved by alkylation of phenylphosphine borane with gamma-iodo-alpha-amino ester reagents under phase transfer catalysis (PTC). Second, a sec-phosphine borane amino ester was saponified and coupled with alpha,gamma-diamino esters to afford the corresponding dipeptide derivatives in good yields. Finally, the hydrophosphination reaction of [60]fullerene by the sec-phosphine borane compounds was performed under PTC to obtain C-60…
Heterogeneity within and between primary colorectal carcinomas and matched metastases as revealed by analysis of Ki-ras and p53 mutations
2004
Analysis of the genetic status of Ki-ras and p53 in primary colorectal carcinomas and matched colorectal liver metastasis from 30 patients reveals an overall heterogeneity both within and between the two tumoral tissues. Both genes were found mutated with a similar frequency in both tissues; however, identical mutations in primary tumor and matched metastasis were found less frequently in the case of the Ki-ras than the p53 gene. Only in three cases the same p53 and Ki-ras mutations found in the primary tumor were found also in the metastasis. In several metastatic specimens the DNA bearing a mutation detected also in the primary tumor appears significantly less abundant than the wild-type …
Ethyl hexanoate transfer in paper and plastic food packaging by sorption and permeation experiments
2008
The barrier properties of one treated paper packaging and one standard plastic film (bi-oriented polypropylene, biOPP) were assessed for ethyl hexanoate. Three methods based either on sorption (gravimetry and micro-atmosphere-derived method) or permeation kinetic determination were used in controlled conditions of aroma vapor concentration (107 Pa), temperature (25 degrees C) and relative humidity (about 0 %). Ethyl hexanoate solubility values were on the same range of magnitude for both packaging films in spite of their different nature and composition. Ethyl hexanoate affinity for both films was well predicted by their respective solubility parameters. Solubility values were different acc…
Identification of Brassicadiene, a Diterpene Hydrocarbon Attractive to the Invasive Stink Bug Bagrada hilaris, from Volatiles of Cauliflower Seedling…
2020
Brassicadiene, a novel tricyclic diterpene hydrocarbon, was identified by a combination of mass spectrometry, microchemical tests, and analysis of NMR spectra. The compound constitutes >90% of the volatile organic compounds produced by cauliflower seedlings, Brassica oleracea var. botrytis. The invasive stink bug Bagrada hilaris is strongly attracted to brassicadiene, providing a mechanism for this herbivore, which specializes on cruciferous plants, to locate its hosts in a nutrient-rich and vulnerable stage.
Role of volatile and contact pheromones in the mating behaviour of Bagrada hilaris (Heteroptera: Pentatomidae)
2008
Volatiles and contact pheromones involved in the mating behaviour of the Painted bug, Bagrada hilaris Burmeister (Het- eroptera: Pentatomidae), were investigated in behavioural and chemical experiments. Vertical open Y-shaped olfactometer bioassays showed that odour from males attract females but not males, while that from females did not attract either gender. Adult females were also attracted by hexane extracts of volatile compounds collected from males. In open arena bioassays, males displayed the characteristic steps of courtship behaviour in the presence of virgin females. Such courtship behaviour was displayed in the presence of females killed by freezing, but not in the presence of f…
Impact of Ageing on Pea Protein Volatile Compounds and Correlation with Odor
2022
Vegetal proteins are of high interest for their many positive aspects, but their ‘beany’ off-flavor is still limiting the consumer’s acceptance. The aim of this work was to investigate the conservation of pea protein isolate (PPI) during time and especially the evolution of their organoleptic quality under two storage conditions. The evolution of the volatile compounds, the odor and the color of a PPI has been investigated during one year of storage. PPI was exposed to two treatments mimicking a lack of control of storage conditions: treatment A with light exposition at ambient temperature (A—Light 20 °C) and treatment B in the dark but with a higher temperature …