Search results for "Guaiac"
showing 10 items of 40 documents
Volatile components of aerial parts of Centaurea nigrescens an C. stenolepis growing wild in the Balkans
2010
The volatile constituents of the aerial parts of Centaurea nigrescens Willd, collected in Romania and of two samples of C. stenolepis A. Kerner from Bulgaria and Romania were obtained by hydrodistillation and analyzed. The main components of C. stenolepis were caryophyllene oxide (6.9-15.6%), hexahydrofarnesyl acetone (6.5-4.4%), heptacosane (6.0-4.9%) and p-vinyl guiacol (4.3-5.0%). The main components of C. nigrescens were caryophyllene oxide (9.9%), β-eudesmol (9.5%), spathulenol (7.6%), heptacosane (6.1%) and p-vinyl guiacol (5.5%). The chemotaxonomic significance with respect to their co-location in Sections Lepteranthus and Nigrescentes, respectively, is discussed.
Analysis of Essential Oil from Teucrium maghrebinum Greuter et Burdet Growing Wild in Algeria
2009
The chemical composition of the essential oil obtained from aerial parts of Teucrium maghrebinum growing wild in Algeria was analyzed by GC and GC-MS. Among the 66 identified compounds, δ-cadinene (12.7%), germacrene D (11.4%), γ-cadinene (9.5%) and 4-vinyl guaiacol (4.0%) were the most abundant. The oil is strongly characterized by the presence of sesquiterpenes (61.5%), particularly hydrocarbon sesquiterpenes (49.6%).
Multiple linear regression analysis of RF values of chlorinated catechols and guaiacols
1981
The multiple linear regression analysis of the RF values of chlorinated catechols and guaiacols has been carried out. The resolved terms, in the regression equation have been used to explain the relative mobility of chlorinated compounds to the reference compound (catechol or guaiacol). The best correlations have been observed for solvent systems which give the greatest standard deviations and relative differences between the RF values. A good correlation between the standard deviation of the RF values and the term which represents the effect of the chlorine atom ortho to the hydroxyl group(s) have also been observed.
CCDC 154581: Experimental Crystal Structure Determination
2001
Related Article: P.Sobota, K.Przybylak, J.Utko, L.B.Jerzykiewicz, A.J.L.Pombeiro, M.F.C.Guedes da Silva, K.Szczegot|2001|Chem.-Eur.J.|7|951|doi:10.1002/1521-3765(20010302)7:5<951::AID-CHEM951>3.0.CO;2-F
CCDC 154580: Experimental Crystal Structure Determination
2001
Related Article: P.Sobota, K.Przybylak, J.Utko, L.B.Jerzykiewicz, A.J.L.Pombeiro, M.F.C.Guedes da Silva, K.Szczegot|2001|Chem.-Eur.J.|7|951|doi:10.1002/1521-3765(20010302)7:5<951::AID-CHEM951>3.0.CO;2-F
Methyl [4-methoxy-3-(methylsulfonyloxy)benzoyl]formate
2005
The crystal structure of the title compound, C11H12O7S, confirms an earlier proposal concerning the regioselectivity of electrophilic substitution reactions of mesyl guaiacol.
Interactions between aroma compounds and beta-lactoglobulin in the heat-induced molten globule state
2010
; he present study aims to elucidate the binding of small hydrophobic ligands onto the molten globule state of β-lactoglobulin (BLG). The conversion of the native BLG into a molten globule state was induced by heat treatment at acidic pH. The molten globule state was evidenced by far and near-UV circular dichroism spectra. β-Ionone and guaiacol exhibited a higher binding ability to BLG in the heat-induced molten globule state compared to unheated BLG, as assessed by protein surface hydrophobicity measurements, using 6-propionyl-2-(dimethylamino)naphthalene (PRODAN) fluorescent probe. The binding sites of the two aroma compounds were determined by 2D nuclear magnetic resonance (NMR) spectro…
Sorption of wine volatile phenols by yeast lees
2005
The capacity of Saccharomyces cerevisiae yeast lees to sorb 4-ethylguaiacol and 4-ethylphenol was investigated in a synthetic medium and in wine. Active dried yeast was more effective when volatile phenols were diluted in red wine. Partition coefficients between wine model solution and wine yeast lees were determined and compared with those measured for dried active yeast. They showed a larger affinity of volatile phenols for wine yeast lees than for dried active yeast. The effect of yeast lees on volatile phenol sorption was sensitive to yeast autolysis level and to physicochemical parameters, such as ethanol content, temperature and pH. These results could be applied in the technology of …
Perceptual interactions between fruity and woody notes of wine
2004
The quantitative olfactory interactions in three binary mixtures of wine aroma compounds were studied. For the first two mixtures, whisky lactone (woody note) was mixed separately with two esters (fruity note), ethyl butyrate and isoamyl acetate. For the third mixture, guaiacol (woody note) was mixed with ethyl butyrate (fruity note). Perceived odour intensity of 24 stimuli (four supra-threshold concentration levels of two compounds and the respective 16 mixtures) were evaluated in five replications, by a trained panel of 13 subjects. The results showed that for the three binary mixtures studied, quantitative perceptual interactions were non-level independent, non-symmetrical, and reached t…
A HS-SPME-GC-MS analysis of IR heated wood: Impact of the water content on the depth profile of oak wood aromas extractability
2013
http://www.sciencedirect.com/science/article/pii/S0963996913003736; International audience; Controlled and reproducible IR heat treatments were applied to oak wood surfaces in order to establish a depth-profiled picture of the extractability of volatile compounds, with particular emphasis on the impact of the initial water content. Headspace-solid phase microextraction-gas chromatography coupled to mass spectrometry (HS-SPME-GC-MS) has been used to compare the concentrations of six aroma compounds (vanillin, furfural, eugenol; guaiacol and cis- and trans-whisky lactones) in hydroalcoholic extracts of series of slices representative of the first 8 mm of the wood facing the IR source. Results…