• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.964-971
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• 1995

Volatile flavor compounds and free amino acids in untreated and hydrolysate pen shell by-product produced with APL 440 protease were compared by vacuum simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry. A total of 109 volatile flavor compounds were detected in hydrolysate (65 compounds) or the 109 volatile flavor compounds were detected in untreated pen shell by-product (88). These compounds were composed of aldehydes(16), ketones(17), alcohols(31), nitrogen containing compounds (16), aromatic hydrocarbon compounds(8), esters(3), and miscellaneous compounds (17). Levels of aldehydes and aromatic hydrocarbons decreased after hydrolysis, whereas levels of nitrogen containing compounds increased 3 times than in untreated pen shell by-product. Taurine, known to be having a physiological function, was accounted for 31.25% of total amino acids in hydrolysate.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.881-888
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• 1994

The approximate rates and stoichiometry of the reaction of excess sodium tris(diethylamino)aluminum hydride (ST-DEA) with selected organic compounds containing representative functional groups under standardized conditions(tetrahydrofuran, $0{\circ}$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of STDEA was also compared with those of the parent sodium aluminum hydride (SAH) and lithium tris(diethylamino)aluminum hydride (LTDEA). The reagent appears to be milder than LTDEA. Nevertheless, the reducing action of STDEA is very similar to that observed previously for LTDEA, as is the case of the corresponding parent sodium and lithium aluminum hydrides. STDEA shows a unique reducing characteristics. Thus, benzyl alcohol, phenol and 1-hexanol evolved hydrogen slowly, whereas 3-hexanol and 3-ethyl-3-pentanol, secondary and tertiary alcohols, were essentially inert to STDEA. Primary amine, such as n-hexylamine, evolved only 1 equivalent of hydrogen slowly. On the other hand, thiols examined were absolutely stable. STDEA reduced aidehydes and ketones rapidly to the corresponding alcohols. The stereoselectivity in the reduction of cyclic ketones by STDEA was similar to that by LTDEA. Quinones, such as p-benzoquinone and anthraquinone, were reduced to the corresponding 1,4-dihydroxycyclohexadienes without evolution of hydrogen. Carboxylic acids and anhydrides were reduced very slowly, whereas acid chlorides were reduced to the corresponding alcohols readily. Esters and epoxides were also reduced readily. Primary carboxamides consumed hydrides for reduction slowly with concurrent hydrogen evolution, but tertiary amides were readily reduced to the corresponding tertiary amines. The rate of reduction of aromatic nitriles was much faster than that of aliphatic nitriles. Nitrogen compounds examined were also reduced slowly. Finally, disulfide, sulfoxide, sulfone, and cyclohexyl tosylate were readily reduced without evolution of hydrogen. In addition to that, the reagent appears to be an excellent partial reducing agent: like LTDEA, STDEA converted ester and primary carboxamides to the corresponding aldehydes in good yields. Furthermore, the reagent reduced aromatic nitriles to the corresponding aldehydes chemoselectively in the presence of aliphatic nitriles. Consequently, STDEA can replace LTDEA effectively, with a higher selectivity, in most organic reductions.

• Journal of Life Science
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• v.21 no.2
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• pp.292-299
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• 2011

This study compared volatile flavor profiles of 4 commercial vinegar beverages (Italian vinegar beverage (IVB), Japanese vinegar beverage (JVB), Japanese Yuzu-Ponz (JYP), and Korean white wine vinegar beverage (KWVB)). Flavor components of vinegar beverages (VBs) were determined using SPME/GC/MSD. The profiles of VBs were as follows; IVB (11 acids, 17 esters, 10 alcohols, 8 aldehydes, 3 terpenes, 4 aromatic hydrocarbons, 9 ketones), JVB (7 acids, 8 esters, 9 alcohols, 7 aldehydes, 13 terpenes, 7 aromatic hydrocarbons, 1 ketones, 3 miscellaneous compounds), JYP (3 acids, 12 esters, 8 alcohols, 7 aldehydes, 63 terpenes, 6 aromatic hydrocarbons, 2 ketones, 5 miscellaneous compounds), KWVB (10 acids, 10 esters, 9 alcohols, 8 aldehydes, 2 terpenes, 5 aromatic hydrocarbons, 4 ketones, 2 miscellaneous compounds). IVB and JVB showed similar flavor compositions (acids, ketones and esters in particular), whereas major components in JYP and KWVB were terpenes (79.6%) and acids (81.0%), respectively. Five compounds including 2-phenylethyl acetate (floral, fruity, sweet odor), 2-phenylethanol (floral, rose odor), vitispirane (fruity odor), geranylacetone (fragrant odor) and acetic acid were identified as major components in balsamic vinegar beverages.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.6
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• pp.437-440
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• 2006

To develop natural crab-like flavorants from red snow crab Chionoecetes japonicus cooker effluent (RSCCE), the flavor was analyzed during the concentration of RSCCE up to $40^{\circ}Brix$. Using solid phase microextraction (SPME)/gas chromatography (GC)/mass selective detection (MSD), 30 volatile flavor compounds were detected in four RSCCE samples (10, 20, 30, and $40^{\circ}Brix$). These comprised 12 aromatic compounds, 5 N-containing compounds, 2 5-containing compounds, 2 alcohols, 2 aldehydes, and 7 miscellaneous compounds. The amounts of all volatiles except alcohols and aldehydes increased significantly with the concentration (p<0.05). Of the volatiles detected, the most abundant was a dimethyl trisulfide with an odor like onion/cooked cabbage. Of the N-containing compounds (nutty, roasted peanut-like odor), 2-ethyl-5-methylpyrazine was the most abundant, followed by 2,5-dimethylpyrazine and 2-methyl-5-isopropylpyrazine in that order (p<0.05). The N- and S-containing compounds with characteristic odors detected in this experiment are thought to play a positive role in RSCCE during concentration.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.644-649
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• 2011

Polyaniline/$SiO_2$ catalyzed one-pot mannich reaction of acetophenone, aromatic aldehydes and aromatic amines are carried out in ethanol to afford various ${\beta}$-amino ketones. The various wt% of polyaniline were supported on pure silica synthesized by using chemical oxidative method. The catalyst prepared has been characterized by means of thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR). Solvent stability of catalyst was tested using UV-Visible spectroscopy. This protocol has several advantages such as high yield, simple work up procedure, non-toxic, clean, easy recovery and reusability of the catalyst.

• BMB Reports
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• v.28 no.2
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• pp.162-169
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• 1995

Rat brain succinic semialdehyde dehydrogenase (EC 1.2.1.24 SSADH) activity was detected in mitochondrial, cytosolic and microsomal fractions. Brain mitochondrial soluble SSADH was purified by ammonium sulfate precipitation, DEAE Sephacel, and 5'-AMP Sepharose 4B affinity chromatography. The purified enzyme was shown to consist of four identical subunits, and the molecular weight of a subunit was 55 kD. The $K_m$ for short chain aliphatic aldehydes and aromatic aldehydes were at the $10^{-3}M$ level but that for succinic semialdehyde was 2.2 ${\mu}M$. Either $NAD^+$ or $NADP^+$ can be used as a cofactor but the affinity for $NAD^+$ was 10 times higher than that for $NADP^+$. The brain cytosolic SSADH was also purified by ammonium sulfate precipitation, DEAE Sephacel, Blue Sepharose CL-6B and 5'-AMP Sepharose 4B affinity chromatography and its Km for short chain aliphatic aldehydes was at the $10^{-3}$ level but that for succinic semialdehyde was 3.3 ${\mu}M$. $NAD^+$ can be used as a cofactor for this enzyme. We suppose that both enzyme might participate in the oxidation of succinic semialdehyde, which is produced during GABA metabolism. The activity of both cytosolic and mitochondrial SSADH was markedly inhibited when the concentration of succinic semialdehyde was high. The reciprocal plot pattern of product inhibition and initial velocity indicated a sequential ordered mechanism for mitochondrial matrix SSADH. Chemical modification data suggested that amino acid residues such as cysteine, serine and lysine might participate in the SSADH reaction.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.469-475
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• 1993

The approximate rates and stoichiometry of the reaction of excess lithium tris(diethylamino)aluminum hydride (LTDEA) with selected organic compounds containing representative functional groups under standardized condition (tetrahydrofuran, 0$^{\circ}C$) were examined in order to define the characteristics of the reagent for selective reductions. The reducing ability of LTDEA was also compared with those of the parent lithium aluminum hydride (LAH) and lithium tris(dibutylamino)aluminum hydride (LTDBA). In general, the reactivity toward organic functionalities is in order of LAH${\gg}$LTDEA${\geq}$LTDBA. LTDEA shows a unique reducing characteristics. Thus, benzyl alcohol and phenol evolve hydrogen slowly. The rate of hydrogen evolution of primary, secondary, and tertiary alcohols is distinctive: 1-hexanol evolves hydrogen completely in 6 h, whereas 3-hexanol evolves hydrogen very slowly. However, 3-ethyl-3-pentanol does not evolve any hydrogen under these reaction conditions. Primary amine, such as n-hexylamine, evolves only 1 equivalent of hydrogen. On the other hand, thiols examined are absolutely inert to this reagent. LTDEA reduces aldehydes, ketones, esters, acid chlorides, and epoxides readily to the corresponding alcohols. Quinones, such as p-benzoquinone and anthraquinone, are reduced to the corresponding diols without hydrogen evolution. However, carboxylic acids, anhydrides, nitriles, and primary amides are reduced slowly, where as tertiary amides are readily reduced. Finally, sulfides and sulfoxides are reduced to thiols and sulfides, respectively, without evolution of hydrogen. In addition to that, the reagent appears to be an excellent partial reducing agent to convert esters, primary carboxamides, and aromatic nitriles into the corresponding aldehydes. Free carboxylic acids are also converted into aldehydes through treatment of acyloxy-9-BBN with this reagent in excellent yields.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.41-54
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• 2010

담배 주류연은 수천가지 종류의 다양한 형태의 화학물질로 구성되어있고, 이들 화학물질의 대부분은 극히 미량의 농도로 존재하는 것으로 알려져 있다(Green and Rodgman, 1996). 담배연기 속에서 발암물질로서는 poly cyclic aromatic hydrycarbon (PAHs) 류인 B(a)P를 최초로 보고된 이후, 현재까지 69종의 화합물이 담배연기중의 발암물질로서 알려졌으며, 여기에는 9종의 PAHs 그리고 4종의 aromatic amine, nitrosoamines 및 aldehydes 그리고 다른 무기 및 유기 화합물들을 포함된다. 또한 담배 주류연에는 여러 화학물질들에 의해 유발된 생물학적 독성을 상당히 감소시키는 것으로 확인된 성분들이 존재하는 것으로 알려져 있다. 이러한 담배연기 중에 존재하는 항 발암성 효과를 나타내는 성분들의 작용 메카니즘은 발암성 물질 또는 발암성 물질의 대사산물들과 반응을 하거나, 불활성화 시키거나, 세포 구성 물질들과의 반응에서 서로 경쟁하거나, 또는 발암성의 흡수를 간섭함으로서 발암성 효과를 없애거나 또는 감소시키는 것으로 생각된다. 여러 연구자들은 담배연기 응축물에서 종양 성장의 억제 작용을 하는 성분들이 존재하는 것으로 주장 하고 있다.(Hoffmann and Griffin, 1958; Fall et al., 1964; Homburger and Tregier, 1965). 담배 연기 중에는 발암성을 나타내는 성분들과 함께 항 발암성 및 항 돌연변이성 효과를 나타내는 성분들이 존재한다는 것이 다양한 생물학적 평가 연구들에 의해 증명되었다(Slaga and DiGivanni, 1984; Fay et al., 1984; Green and Rodgman, 1996).

• Journal of ILASS-Korea
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• v.24 no.1
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• pp.21-26
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• 2019

In Korea, Medium-duty trucks are classified into GVW (Gross Vehicle Weight) 3.5~10tons. MDTs are mostly used for logistics or delivery between regions. There have been studied on diesel fuel vehicles for SUVs(Sports Utility Vehicle) or light-duty trucks. But MDTs have been not studied. Therefore, this study have been used MDTs for characteristic exhaust emission. Test was carried out using the certification test mode (NEDC, New European Driving cycle) and the NIER mode in chassis dynamometer of the MDTs. And emission gas was analyzed for PN (Particulate Number), PN size distribution and aldehydes, VOCs (Volatile Organic Compounds), PAHs (Polycyclic Aromatic Hydrocarbons). This paper concluded that EURO-IV trucks produced more MSATs than EURO V trucks. Depending on the engine temperature, more MSATs were generated in cold temperature than in the hot start operation. However, the driving speed, the opposite results was obtained.

• Analytical Science and Technology
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• v.18 no.5
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• pp.431-435
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• 2005

In order to evaluate the hazardous effects of environmental tobacco smoking (ETS), we measured the concentrations of major aromatic VOC from those who decided to participate in a program to quit smoking. By acquiring the air samples both before and after quitting smoking (QS), we were able to compare their BTEX concentration levels in their breathing air. The results of our study clearly showed that BTEX levels in respiring air samples were significantly high prior to the QS period. It was found that toluene maintained the highest concentration levels both before and after the QS period. However, the level of reduction was most significant in the case of benzene, as it was decreased 10 times from 4.8 to 0.46 ppb. When their reduced BTEX levels are compared to those who never smoked before, differences were not significant enough to distinguish in statistical terms. The overall results of this preliminary study suggest that BTEX levels in breathing air samples can be used as one of the most sensitive signals to judge the effect of QS.