• Journal of the Korean Society of Tobacco Science
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• v.22 no.2
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• pp.114-122
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• 2000

This study was carried out to investigate the changes in the composition of essential oils for the improvement of air-curing process of burley tobacco leaves. From the essential oils isolated from the cured tobacco leaves by steam distillation method, 90 compounds including 15 acids and esters, 19 alcohols, 23 aldehydes and ketones, 19 hydrocarbons, and 14 miscellaneous compounds, could be identified by gas chromatography and gas chromatography-mass spectrometry. Among them, acids and esters were gradually decreased during the progress of curing after harvesting. A rapid increase in alcohol content was observed in the earlier stage of curing, but thereafter, decrease followed until the end of curing However, aldehyde and ketone groups were continuously increased during curing and were 3 times higher in quantity after curing than at the harvesting time. The concentration of hydrocarbons was increased in the earlier stage of curing, but gradually decreased from the middle stage. The miscellaneous compounds were continuously increased in content until the end stage of curing, with rapid increased in the earlier stage of curing.

• Journal of Integrative Natural Science
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• v.1 no.3
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• pp.192-194
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• 2008

A series of non-free hydride reducing systems containing boron or aluminum atom, which possess no metal-hydride bond but an available hydrogen at a branched ${\beta}$-position, has been applied to the selective reduction (chemo--, regio-, and stereoselective reduction) of organic compounds. The systems, comprised of diisopinocampheylborane and diisobutylalane derivatives, exhibited almost perfect selectivities in the reduction of aldehydes and ketones. The characteristics features of this systems leading to a perfect transformation have been depicted in this report, especially in the 1) Reduction of ${\alpha}$,${\beta}$-Unsaturated Carbonyl Compounds to Allylic Alcohols via 1,2-Reduction, 2) Chemoselective Reduction between Structurally Different Carbonyl Compounds, and 3) Stereoselective Reduction of Cyclic Ketones.

• Natural Product Sciences
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• v.26 no.2
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• pp.132-135
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• 2020

Volatile constituents obtained by water distillation from the aerial parts and root of Onosma dichroanthum Boiss (Boraginaceae) native to the north of Iran were investigated by GC and GC/MS for the first time. Palmitic acid (39.61%) and decane (31.39%) were the major components in the root while decane (26.26%) and phytol (25.52%) were the predominant constituents in the aerial parts. Ketones, aldehydes, alkanes, fatty acids, oxygenated diterpenes and sesquiterpenes were characterized as the most phytochemicals in the aerial parts. Alkanes and fatty acids were identified as the main groups in the root volatile substances. There were two ketone derivatives, belong to apocarotenoids, in the aerial parts; β-ionone and hexahydrofarnesyl acetone.

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.147-151
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• 2010

The volatile aroma constituents of Atractylodes japonica rhizome were separated by steam distillation extraction method using a Clevenger-type apparatus, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of the essential oil from Atractylodes japonica was 1.0% (v/w), and its color was pale yellow. Forty-five volatile flavor compounds, which make up 93.86% of the total peak area, were tentatively identified in the rhizome oil. The oil contained 32 hydrocarbons (79.19%) with sesquiterpene hydrocarbon predominating, 3 esters (12.46%), 4 alcohols (0.11%), 1 ketone (0.01%), 2 aldehydes (0.02%), and 3 miscellaneous compounds (2.07%).

• Applied Biological Chemistry
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• v.34 no.4
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• pp.344-352
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• 1991

The whole volatile flavor concentrate obtained from Jindalrae flower was separated into hydrocarbon and oxygen-containing compound(OCC) fractions, and the OCC-fraction was further separated by column chromatography into nine sub-fractions, respectively. These fractions were analyzed by gas chromatography and combined gas chromatography/mass spectroscopy. One hundred and sixty-two components, including 61 hydrocarbons, 18 aldehydes, 18 esters, 41 alcohols, 3 ketones, 4 oxides, 8 acids, 6 phenols and 3 miscellaneous components, were identified.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2419-2421
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• 2009

A simple and efficient method has been developed for Knoevenagel condensation between aldehydes or ketones and active methylene group by stirring in methylene chloride at 60 ${^{\circ}C}$ under heterogeneous conditions using silica supported ammonium acetate. The products are obtained in excellent yields and are in a state of high purity. The structures of the products were confirmed by IR, $^1H$ NMR and mass spectral data and comparison with authentic samples available commercially.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3738-3742
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• 2011

Bismuth tribromide ($BiBr_3$) catalyzed Mannich-type reactions of N-acyliminium ions which generated in situ from N-benzyloxycarbonylamino p-tolylsulfones have been developed. In the presence of catalytic amount of $BiBr_3$, N-benzyloxycarbonylamino p-tolylsulfones prepared from aromatic and aliphatic aldehydes reacted with silyl enol ether and silyl enol ester under mild reaction conditions to afford N-Cbz-protected ${\beta}$-amino ketones and N-Cbz-protected ${\beta}$-amino esters in moderate to good yield, respectively.

• Korean Journal of Pharmacognosy
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• v.24 no.3
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• pp.192-196
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• 1993

Essential oil of the root of Angelica decursiva(Miq.) Fr. et Sav. (Umbelliferae) was investigated. Essential oil was obtained from the dried roots by steam distillation and fractionated by column chromatography. Each isolate or fraction was identified by GC, GC-MS and spectral analysis. It was found to contain ten monoterpenes such as ${\alpha}-pinene$ (7.0%) etc. Three hydrocarbons, two aldehydes, three sesquiterpenes, two sesquiterpene alcohols, one aromatic compounds, one ketone, isobonyl acetate and two lactones were tentatively identified.

• Food Science and Preservation
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• v.13 no.1
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• pp.108-114
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• 2006

This study was conducted to determine the volatile flavor compositions of the essential oil and the headspace of Capsella bursa-pastoris Medicus. Essential oil and headspace from the plant were extracted by simultaneous steam distillation extraction (SDE), and solid-phase microextraction(SPME) methods, respectively. Seventy-two compounds including 28 hydrocarbons, 4 aldehydes, 6 ketones, 16 alcohols, 4 esters, 8 acids, and 6 miscellaneous ones were identified in the leaf essential oil extracted by SDE method Sixty-eight compounds including 26 hydrocarbons, 2 aldehydes, 6 ketones, 17 alcohols, 4 esters, 6 acids, and 7 miscellaneous ones were identified in the root essential oil. According to the instrumental analyses the essential oil, phytol ($21.12\%$ in leaves, $20.94\%$ in roots) was the most abundant compound Alcohols, esters, and acids were main groups of the essential oil. On the other hand, thirty-eight compounds including 18 hydrocarbons, 3 aldehydes, 3 ketones, 9 alcohols, 2 esters, 3 miscellaneous ones were identified in the leaf headspace by SPME. In root headspace, thirty-three compounds including 16 hydrocarbons, 2 aldehydes, 1 ketone, 9 alcohols, 3 esten;, and 2 miscellaneous ones were identified. Hydrocarbons($44.02\%$ in leaves, $56.98\%$ in roots) were the main components of the headspace of Capsella bursa-pastoris Medicus.

• Culinary science and hospitality research
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• v.13 no.1 s.32
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• pp.119-128
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• 2007

Volatile flavor compounds of sauces made from shrimps, crabs or lobsters were analyzed by the combination of canister system, gas chromatography(GC) and mass selective detector(MSD). Of 72 total volatile compounds from 4 kinds of sauces, 45 compounds were identified from shrimp sauce(SS). Ten alkanes, 5 ketones, 3 aldehydes were obtained from SS. Especially, 3-methyl-2-butanone, 2-pentanamine, isobutane, 3-methyl-2-butanol, carbon disulfide and dimethyl sulfide were predominant compounds in SS. In crab sauce(CS), there were 18 compounds identified, including 4 alcohols, 4 alkanes, 3 aldehydes, 2 ketones, acid and amine. 2-Methoxy ethanol, trimethyloxirane and 3-buten-1-ol were special volatile compounds in CC. Volatile compounds from lobster head sauce(LHS) or lobster shell sauce(LSS) were 16 or 18 kinds respectively. The major volatile compounds of LHS were formic acid, 1-propanethiol, $\beta$-pinene and allyl sulfide, and those of LSS were acids, pentane, 3-methyl-1-butanol and 2,4-dimethyl-3-pentanone. It was thought that the volatile compounds identified from sauces as well as shrimps, crabs or lobsters might come from wine, onions, bay leaves or celery used as minor ingredients.