• Journal of the Korean Chemical Society
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• v.20 no.1
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• pp.59-72
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• 1976

The addition of one mole of zinc chloride to 2.33 moles of sodium borohydride in tetrahydrofuran at room temperature gave a clear chloride-free supernatant solution of zinc borohydride after stirring three days and standing at room temperature.The approximate rates and stoichiometry of the reaction of zinc borohydride with 54 selected organic compounds were determined in order to test the utility of the reagent as a selective reducing agent. Aldehydes and ketones were reduced rapidly, aromatic ketones being somewhat slowly, and the double bond of cinnamaldehyde was not attacked. Acyl halides were reduced rapidly within one hour, but acid anhydrides were reduced at a moderate rate. Carboxylic acids, both aliphatic and aromatic, were slowly reduced to alcoholic stage. Esters were inert to this reagent but a cyclic ester, γ-butyrolactone, was slowly attacked. Primary amides were reduced slowly with partial evolution of hydrogen, whereas tertiary amides underwent neither reduction nor hydrogen evolution. Epoxides and nitriles were all inert, as well as nitro, azo, and azoxy compounds. Cyclohexanone oxime and phenyl isocyanate were reduced slowly but pyridine was inert. Disulfide, sulfoxide, sulfone and sulfonic acids were stable to this reagent.

• Analytical Science and Technology
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• v.17 no.5
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• pp.410-415
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• 2004

In order to learn the emission characteristics of hazardous pollutants associated with environmental tobacco smoking (ETS), we measured the concentrations of major aromatic VOC and carbonyl compounds released from ETS. By acquiring the different smoke types of ETS, we were able to determine that the concentrations of those species range from ppb (normal exhaled air of smoker prior to smoking) to ppm levels (direct release of ETS without filter). Using these measurement data, we also evaluated the body-retaining rate of these compounds as the result of ETS. The results of our analysis indicated that predominant portion of them (e.g., > 99%) are retained as the result of cigarette smoking. To learn more about the potential impact of ETS, more extensive study may be required to assess the gross picture of pollutant deposition inside respiratory intake and their health-effects.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.258-264
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• 2004

The pyrazole family was discovered as effective insecticides/acaricides, and fenpyroximate and tebufenpyrad were introduced in the market. In this study, new series of pyrazole oxime ethers were designed and synthesized. The pyrazolone 1 was prepared by the condensation of ethyl acetoacetate with methylhydrazine, and then subsequently subjected to the Vilsmeier-Haack chloroformylation yielding 4-formyl-5-chloro-pyrazole 2. The nucleophilic aromatic substitution of 2 generally allowed the introduction of a wide range of heterocycles into the pyrazole ring. The resulting pyrazole aldehydes 3a-i were readily converted to the corresponding pyrazole oxime derivatives 4a-i, and subsequently to 5-substituted pyrazole oxime ether derivatives 6a-i. The screening assay results clearly show that the activities of 6d were comparable to those of fenpyroximate (6a) against BPH, DBM, and TSSM. It indicates that 6d has a potential to be developed as an insecticidal agent.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.80-88
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• 2016

The enzyme-catalyzed Henry reaction was realized using deep eutectic solvents (DESs) as a reaction medium. The lipase from Aspergillus niger (lipase AS) showed excellent catalytic activity toward the substrates aromatic aldehydes and nitromethane in choline chloride:glycerol at a molar ratio of 1:2. Addition of 30 vol% water to DES further improved the lipase activity and inhibited DES-catalyzed transformation. A final yield of 92.2% for the lipase AS-catalyzed Henry reaction was achieved under optimized reaction conditions in only 4 h. In addition, the lipase AS activity was improved by approximately 3-fold in a DES-water mixture compared with that in pure water, which produced a final yield of only 33.4%. Structural studies with fluorescence spectroscopy showed that the established strong hydrogen bonds between DES and water may be the main driving force that affects the spatial conformation of the enzyme, leading to a change in lipase activity. The methodology was also extended to the aza-Henry reaction, which easily occurred in contrast to that in pure water. The enantioselectivity of both Henry and aza-Henry reactions was not found. However, the results are still remarkable, as we report the first use of DES as a reaction medium in a lipase-catalyzed Henry reaction.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.5
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• pp.527-537
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• 2012

The increasing consumption of pseudo-petroleum products (PPP) has been disturbing the national petroleum market. The use of PPP lead to tax evasion, disturbance of sound trading principles, component corrosion of cars, and explosion accident. Also, PPP have emitted hazardous air pollutants (HAP) including the carcinogenic aromatic hydrocarbons, PAHs and aldehydes more than regular-petroleum products. It thus has potentials to cause many environmental and health care problems. In this study, benzene, toluene and xylene emissions from road transport vehicles due to the use of pseudo-gasoline are estimated for the year 2008. The results of our study provide emission estimates of benzene, toluene and xylene for the year as 405, 1,711, 717 tonne/yr, respectively for regular-gasoline. BTX emissions are calculated as 452~515, 1,882~2,264 and 732~752 tonne/yr when the amount of pseudo-gasoline is estimated to account for 6~13% for regular-gasoline consumption. BTX emissions increased as much as 12~27, 10~32, 2~5% by using pseudo-gasoline. It is found that the pseudo-gasoline should be the key component to produce HAP in urban area.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2724-2730
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• 2012

A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [$PYC_4SO_3H$][$HSO_4$], and characterized using FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.430-435
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• 2011

Coal fly ash of thermal power plants converted into mesoporous materials MCM-41. The synthesized material was characterized by XRD, FT-IR, SEM, and EDS techniques. The catalytic activity of prepared material was studied for the synthesis of 5-arylindene malononitriles via Knoevenagel condensation of aromatic aldehydes and malonontrile is described. The features of present method are easy handling, stability, reusability, and eco-friendliness of catalyst, high yields, short reaction time, simple experimental and work up procedure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1053-1058
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• 1998

Volatile flavor compounds in salt fermented big eyed herring were analyzed by vacuum simultaneous distillation solvent extraction/gas chromatography/mass spectrometry/olfactometry and aroma extract dilution anlaysis. A total of 44 volatile compounds were detected by GC/O analysis. Of these, 23 were positively identified, and composed of aldehydes(7), esters(5), ketones(4), sulfur containing compounds (3), aromatic hydrocarbons(2), alcohol(1) and nitrogen containing compound(1). Predominant odorants (Log3FD$\geq$5) in sample were ethyl butanoate(bubble gum /sweet candy-like), 3 methylbutyl butanoate (almond /nutty), 1 octen 3 one(earthy/mushroom like), (E,E) 2,6 nonadienal(roasted wheat/grainy), dimethyl trisulfide(soy sauce /cooked cabbage like), 2 acetylpyrazine(nutty/baked potato like) and unidentified compound(RI=1867, seaweed like).

• Journal of Life Science
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• v.11 no.1
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• pp.35-42
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• 2001

Irradiation-induced volatile flavor compounds in irradiated (0, 1, 3, 5, 10 kGy) pork meats were analyzed by liquid liquid continuous extraction (LLCE) and gas chromatography/mass spectrometry (GC/MS) methods. One hundred nine volatile compounds were detected in irradiated pork meats. These compounds were mainly composed of hydrocarbons (42 compounds), aromatic compounds (39), aldehydes(9), ketones(5) and miscellaneous compounds (14). Among these, three volatile compounds, such as decene, 1,2,3,4,-tetrahydro-6-methylnaphthalene and 1,2,3,4-tetrahydro-dimethylnaphthalene were selected as irradiation-induced compounds comparing with irradiation dosages in irradiated pork meats. By the high correlation coefficient with the increment of irradiation dose, however, decene (r=0.93) was considered as marker compound for detecting irradiation dosage in fresh pork meats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.224-231
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• 2009

Volatile components in Olive Flounder fed diets containing 0, 2,5, 5.0, and 7.5% yuza (Citrus junas Sieb ex Tanaka) for 4 months were investigated. Samples were extracted by solid-phase micro extraction and analyzed by gas chromatography/mass spectrometry. Among 89 compounds detected, 82 were positively identified. Volatile compounds of Olive Flounder fed the unsupplemented diet comprised 12 acids, 10 alcohols, eight aldehydes, five aromatic compounds, nine esters, 12 hydrocarbons, four ketones, two monoterpenes, and one miscellaneous compound. Compounds identified in Olive Flounder fed the yuza-supplemented diets consisted of 10 esters, 11 monoterpenes, 13 sesquiterpenes, and two miscellaneous compounds, with the other compounds being the same as in the control. The most abundant class of compounds in flounders fed the yuza-supplemented diet was the monoterpenes, which included limonene, $\beta$-terpinene, $\beta$-trans-ocimene, and $\alpha$-terpinolene. Of the 13 sesquiterpenes identified in flounder fed the yuza-supplemented diet, bicyclogermacrene was the major volatile compound followed by allo-aromadendrene, trans-caryophyllene, and $\delta$-cadinene. Bicyclogermacrene and germacrene D content increased significantly as the yuza supplementation increased.