Gaston Vernin

THERMAL DECOMPOSITION OF ASCORBIC ACID

Abstract Thermal degradation of l -ascorbic acid at 300 °C in the absence of a solvent yielded mostly furan derivatives and α,β-unsaturated cyclic ketones with a five-membered ring. Some of the furan derivatives are the same as those obtained in the Maillard reaction, with the reductones undergoing retroaldol reaction, decarboxylation, oxidation, and hydrolysis. In propylene glycol, under milder conditions (180 °C), the carbonyl and dicarbonyl derivatives resulting from the decomposition react with the solvent and give cyclic acetals and ketals (1,3-dioxolanes). The products were identified by GC-MS using the SPECMA data bank.

Extraction and GC/MS Analysis of the Essential Oil of Achillea millefolium L. complex (Compositae)

ABSTRACT The essential oil, which was obtained by hydrodistillation from aerial parts of Achillea millefolium L. complex (Compositae), was analyzed using both GC/MS and Kovats indices. The major components extracted from the stems, leaves and inflorescences were found to be β-thujone (8.3–21.7%), camphor (8.6–11.7%), 1, 8-cineole (7.7–15.2%), β-pinene (3.8–7.8%) and sabinene (5.7–8.9%). More than sixty components have been identified; forty of which, mainly oxygenated compounds, are reported for the first time. Variations in the essential oil composition and yield during hydrodistillation are also reported.

Analysis of the Volatile Compounds of Psidium cattleianum Sabine Fruit from Reunion Island

Abstract Volatile aroma compounds from red (Psidium cattleianum, Sabine) and yellow (Psidium cattleianum, Sabine, var. lucidum Hort.) guava fruits were analyzed by GC and GC/MS. Among the compounds identified were: 31 hydrocarbons, 9 acetals, ethers and oxides, 13 aldehydes, 13 ketones, 30 esters, 48 alcohols, 2 acids, 2 sulfur-containing compounds, 4 phenol derivatives, menthofuran and coumarin. The following compounds are thought to contribute to the aroma of the red fruit. Fruity notes are due to ethyl esters (C4-Cl6), tiglates, cinnamates, while floral notes can be attributed mainly to terpenic alcohols, 2-phenylethyl alcohol, β-ionone and 1-phenylpropane-1,2-dione. Spicy notes may be due to cinnamaldehyde, eugenol, methyl isoeugenols, while burnt notes are due to furfural and 2-acetylfuran. The herbaceous, slightly spicy-like odor can be attributed to 2-tridecanone and the sweet and balsamic notes to benzyl benzoate. The guava aroma is characterized by the quasi absence of lactones.

Volatile Constituents of the Essential Oil of Santolina chamaecyparissus L.

ABSTRACT The essential oil of Santolina chamaecyparissus L. was analyzed by a combination of gas chromatography and mass spectrometry. The oil was found to contain over 140 constituents of which 70 were identified. The major components were artemisia ketone (ca. 45%) and myrcene (15%).

GC-MS-SPECMA bank analysis of JUniperus communis needles and berries

Abstract Using a combination of gas chromatography-mass spectrometry (electron impact) as well as the headspace technique, more than 70 compounds were found in the juniper needle oil obtained from plants growing in southeastern France (Provence). A comparison between the headspace of fresh and bottled black berries shows a significant loss of the monoterpenoid fraction with time. In the green berries (unripe) this loss is more marked. A sesquiterpenoid fraction of the Juniperus communis needle oil was also investigated by means of the GC (FID) and GC-MS (EI, PCI). Among more than 100 isolated constituents, 64 were sesquiterpenoids. The presence of several oxygen-containing derivatives based on the calamene and calacorene isomers was established but their structures were not fully determined. The various compounds were identified on the basis of our SPECMA data bank (mass spectra and Kovats indices) and our own files.

Mass Spectra and Kovats Indices of Some New cis-Chrysanthenyl Esters Found in the Essential Oil of Artemisia herba alba from Algeria

ABSTRACT The GC/MS analysis of an essential oil of Artemisia herba alba from Algeria has shown the presence often cis-chrysanthenyl esters among more than 300 compounds separated. Identifications were based upon mass spectra and Kovats indices of known cis-chrysanthenol and its acetate.

Volatile Constituents of the Jamrosa Aroma Syzygium jambos L. Aston from Reunion Island

ABSTRACT GC/MS analyses on polar and apolar columns of an aromatic extract of the fruit of Jamrosa-tree from Reunion allowed the identification of 80 volatile compounds: 12 hydrocarbons, 8 oxides and acetals, 12 aldehydes, 9 ketones, 5 esters, 31 alcohols, 3 acids. The presence of a few furan derivatives (unsaturated γ-lactones) is suspected. Among the identified compounds, geraniol, nerol, β-phenylethyl alcohol, linalool, hotrienol, citronellol, four linalool oxides (furans and pyrans), rose oxides and nerol oxide are well-known components of the Bulgarian rose oil. Other compounds, such as, (E)- and (Z)-cinnamaldehydes and their corresponding alcohols and acetates, 3-phenylpropyl alcohol and 3-phenyl propanal are responsible for the cinnamon-spicy-like note of this exotic fruit.

Kinetics and thermal degradation of the fructose-methionine Amadori intermediates. GC-MS/SPECMA data bank identification of volatile aroma compounds

Abstract Fructose-methionine Amadori intermediates, prepared from d -glucose and l -methionine, were purified by semi-preparative HPLC. Structural elucidation was achieved by 13 C-NMR and mass spectrometry in the FAB + and FAB − modes. Constant rates of formation of glucosylamine and the Amadori intermediate, and their thermal degradation into reductones and methionine as well as into diglucosylamine, were observed. Thermal degradation of the Amadori intermediate gives not only the well-known degradation products of the sugar moiety and methional (from the Strecker degradation of methionine), but also several heterocyclic compounds (pyridines, pyrazines, pyrroles, and furans). Some of them contain a methylthiopropyl group in their side chain. These new compounds were identified by the fragmentation rules and the Kovats index additive properties. Out of the 80 compounds isolated, ∼ 70 were identified.

GC/MS Analysis of the Volatile Constituents of Calamintha nepeta (L.) Savi ssp. nepeta from Southeastern France

Abstract Volatile constituents from wild Calamintha nepeta (L.) subsp. nepeta harvested in the autumn in the vicinity of Marseilles were analyzed by GC and GC/MS on nonpolar and polar columns, respectively. Among the 120 identified compounds, the 11 major constituents were: menthone (52.7%), pulegone (9.1%), piperitone (7.8%), neomenthol (7.6%), menthol (4.3%), limonene (4.0%), isomenthone (1.7%) and 3-octanol (1.6%). Several esters of isovaleric and 2-methylbutyric acids, 14 monoterpenes and 8 sesquiterpenes (hydrocarbons), and many other compounds were present in trace amounts including piperitone oxide, and piperitenone oxide. By comparison with other chemotypes, viz., C. nepeta ssp. glandulosa, described in the literature, our sample belongs to the menthone/pulegone chemotype which is the most common one.

GC/MS Analysis of the Volatile Constituents of the Essential Oils of Pituranthos scoparius (Coss et Dur.) Benth. et Hook, from Algeria

Abstract The essential oils from twigs and seeds of Pituranthos scoparius (Coss et Dur.) Benth. et Hook. (Umbelliferae) obtained by hydrodistillation, were analyzed by GC/MS. From the two oils, 150 and 50 mass spectra were recorded, respectively. Approximately, 94 compounds were identified including 34 hydrocarbons (4 aromatic, 12 monoterpene, 18 sesquiterpene), 2 oxides, 8 aldehydes, 10 ketones, 24 alcohols, 9 phenolic derivatives and 7 miscellaneous compounds. Numerous additional compounds, mainly sesquiterpenoids, remain unidentified. The twig oil contained α-pinene (34%) and apiole (15%) as the two principal components. The major constituents in the seed oil were apiole (52%), bornyl acetate (21%) and α-pinene (11%).