• Food Quality and Culture
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• 제1권1호
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• pp.13-17
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• 2007

The volatile flavor compounds of Saussurea lappa C.B. Clarke, a perennial, aromatic and medicinal herbaceous plant of the Asteraceae family, were isolated by the hydro distillation extraction method using a Clevenger-type apparatus, and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). The plant yielded a light yellow colored oil (0.02%, v/w). From S. lappa C.B. Clarke root oil, sixty-three volatile flavor compounds were tentatively identified, among which sesquiterpene was predominant (21.70%). The identified compounds of the root oil constituted 87.47% of the total peak area. From the constituents making up more than 5% of the volatile flavor components, a long-chain aldehyde, (7Z, 10Z, 13Z)-7, 10, 13-hexadecatrienal, was the most abundant volatile flavor compound (21.20%), followed by dehydrocostuslactone (10.30%) belonging to sesquiterpene lactone, valerenol (5.30%) and vulgarol B (5.06%).

• Carbon letters
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• 제2권3_4호
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• pp.170-175
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• 2001

A petroleum-based isotropic pitch fiber spun by melt-blown method was oxidized in air flow at various conditions. The oxidized pitch fiber obtained was tested for its infusibility and its elemental composition during the process of stabilization. The structural changes were traced by using solvent solubility, FT-IR spectroscopy, and elemental analysis. The samples showed a gradual increase in weight with increasing the oxidization temperature. The weight gain of sample oxidized at $320^{\circ}C$ for 10 min was about 4.5%. The concentration of the pyridine and toluene soluble fraction decreased with an increase in stabilization temperatures. The oxygen uptaken in the stabilization process converted aliphatic side chains into the carbonyl groups. As stabilization proceeded, the more ether and carboxylic acid groups were formed through the oxidations of aldehyde and primary alcohol, and then the carboxylic acid was dehydrated to be aromatic anhydride.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2008년도 제39차 학술발표회
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• pp.133-134
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• 2008

A novel near infrared(NIR) absorbing dyes were synthesized by using bis-aldehyde formyl aromatic compounds and heteroaryl derivatives with the reactive methylene group. These dyes provided a range of the NIR wavelength region about 720 nm value. Also, the light absorbing properties of these dyes were investigated in our experiment results. In generally, these NIR colorants may be potential used for optical recording media, DNA sequencing probe and laser beam printings.

• Archives of Pharmacal Research
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• 제13권2호
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• pp.142-146
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• 1990

Reaction of ethyl 4-chloro-2-phenylpyrimidine-4-carboxylate (4) with 5-chloro-2-methylthiophenol or 3-aryl-4-phenyl-1, 2, 4-triazole-5 thiol yielded the corresponding thioethers (5) and (8a, b), respectively. Careful alkaline hydrolysis of (5) yielded the corresponding carboxylic acid (6). Reaction of (4) with p-aminoacetophenone yielded compound (10) which was reacted with certain aromatic aldehyde to afford the$\alpha,\beta$-unsaturated ketones (11a-d). Condensation of (11a-d) with malononitrile or phenylhydrazine yielded the 2-amino-3-cyanopyridines (12a-f) or the 2-pyrazolines (13a, b) respectively. Seven representative compounds were tested for their in vitro antimicrobial activity against some pathogenic micro-organisms, some of them were proved to be active.

• Bulletin of the Korean Chemical Society
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• 제12권6호
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• pp.644-649
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• 1991

The approximate rates and stoichiometry of the reaction of excess lithium tris(dibutylamino)aluminum hydride (LT-DBA) with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, $0^{\circ}C$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of LTDBA was also compared with those of the parent lithium aluminum hydride and the alkoxy derivatives. The reagent appears to be much milder than the parent reagent, but stronger than lithium tri-t-butoxyaluminohydride in reducing strength. LTDBA shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, acid chlorides, epoxides, and amides readily. In addition to that, ${\alpha},{\beta}$-unsaturated aldehyde is reduced to ${\alpha},{\beta}$-unsaturated alcohol. Quinones are reduced to the corresponding diols without evolution of hydrogen. Tertiary amides and aromatic nitriles are converted to aldehydes with a limiting amount of LTDBA. Finally, disulfides and sulfoxides are readily reduced to thiols and sulfides, respectively, without hydrogen evolution.

• Bulletin of the Korean Chemical Society
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• 제15권8호
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• pp.644-649
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• 1994

The approximate rates and stoichiometry of reaction of excess dipyrrolinoaluminum hydride (DPAH) with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, 0, reagent : compound=4 : 1) were examined in order to define the characteristics of the reagent for selective reductions. The reducing ability of DPAH was also compared with that of bis(diethylamino)aluminum hydride (BEAH). The reagent appears to be stronger than BEAH, but weaker than the parent reagent in reducing strength. DPAH shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, acid chlorides, epoxides, and nitriles readily. In addition to that, ${\alpha},\;{\beta}$-unsaturated aldehyde is reduced to the saturated alcohol. Quinone are reduced cleanly to the corresponding 1,4-reduction products. The examination for possibility of achieving a partial reduction to aldehydes was also performed. Both primary and tertiary aromatic carboxamides are converted to aldehydes with a limiting amount of DPAH. Finally, disulfides and sulfoxides are readily reduced to thiols and sulfides, respectively.

• 한국환경과학회지
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• 제14권2호
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• pp.231-240
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• 2005

The number of cases exceeding environmental standards of atmospheric ozone in the major cities in Korea has steadily increased during the past decades. In order to understand and analyze the atmospheric reactions in the atmosphere, especially the secondary photochemical reactions, smog chambers studies have been performed very actively by many research groups worldwide. However, these studies have focused on the mechanism of photochemical reactions in high concentration conditions, not at the ambient levels. Therefore, in-depth studies in these conditions are essentially needed to realize exact mechanism in the atmosphere near the earth surface, especially at Korean atmospheric conditions. In this experiment, the mechanism of photochemical smog was examined through a comparative experiment of smog chambers under sun light and black light conditions. The results of our study indicated that concentrations of ozone, aldehyde, and PAN increased as the radiation of light source increases. Photochemical reaction patterns can be considered quite similar for both black light and sun light experiments. Based on our experiments using toluene as a reactant which is present at significant high levels in ambient air relative to other VOCs, it was found that toluene could contribute notably to oxidize NO to $NO_2$, this reaction can eventually generate some other photochemical oxidants such as ozone, aldehyde, and PAN. The results of simulation and experiments generally showed a good agreement quite well except for the case of $O_3$. The restriction of oxidization of NO to $NO_2$ seems to cause this difference, which is mainly from the reaction of peroxy radical itself and other reactants in the real gas.

• 한국식품영양과학회지
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• 제41권11호
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• pp.1493-1501
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• 2012

꾸지 뽕나무(C. tricuspidata)의 휘발성 향기추출물의 항산화활성을 2 가지의 시험방법을 이용하여 측정하였다. 그리고 꾸지 뽕나무의 향기추출물에서 동정된 10종의 휘발성 향기성분에 대한 항산화활성도 측정하였다. 꾸지 뽕나무의 줄기 및 뿌리 향기추출물들은 2가지 실험법에서 모두 뚜렷하게 처리농도에 비례하여 항산화활성을 나타내었다. 즉 aldehyde/carboxylic acid assay에서 $500{\mu}g/mL$의 농도로 처리하였을 때, 줄기와 뿌리의 향기추출물은 각각 $77.02{\pm}8.12%$와 $74.19{\pm}6.82%$의 항산화활성을 나타내었으며, lipid/malonaldehyde assay에서 $160{\mu}g/mL$의 농도로 처리하였을 때, 줄기 및 뿌리의 향기추출물은 각각 $61.43{\pm}2.11$ 및 $76.17{\pm}4.25%$의 항산화활성을 나타내었다. 꾸지 뽕나무의 향기추출물에서 동정된 향기성분들은 7종의 terpenes and terpenoides, 14종의 alkyl compounds, 11종의 nitrogen containing heterocyclic compounds, 3종의 oxygen containing heterocyclic compounds, 12종의 aromatic compounds, 9종의 lactones와 7종의 miscellaneous compounds였다. 꾸지 뽕나무의 향기추출물에서 동정된 향기성분들 중에서 eugenol, isoeugenol 및 2,4-bis(1,1-dimethylethyl)phenol은 lipid/malonaldehyde assay에서 $160{\mu}g/mL$의 농도로 처리하였을 때, 각각 $91.74{\pm}1.33$, $94.00{\pm}0.59$ 및 $91.22{\pm}4.74%$의 항산화활성을 나타내었다. 이는 동일한 방법에서 BHT와 ${\alpha}$-tocopherol의 항산화활성이 각각 $91.90{\pm}0.42%$와 $89.47{\pm}3.04%$인 것과 비슷한 수준이었다. 한편 동일한 처리농도에서 vanillin과 2-acetylpyrrole은 각각 $63.36{\pm}5.83$과 $58.62{\pm}6.83%$로서 중간 정도의 항산화활성을 나타내었다. 따라서 꾸지 뽕나무는 산화적 손상으로 인한 질병의 예방과 사람들의 건강에 도움을 줄 수 있을 것으로 생각되었다.

• 농약과학회지
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• 제8권4호
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• pp.258-264
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• 2004

효과적인 살충제로 pyrazole 계통의 화합물이 널리 알려졌으며, 이중에 fenpyroximate와 tebufenpyrad는 시판되고 있다. 본 연구에서는 fenpyroximate의 새로운 유도체로써 5-번 위치가 치환된 pyrazole oxime ether를 합성하였다. 본 연구의 핵심 중간체인 4-formyl-5-chloro-pyrazole 2는 ethyl acetoacetate와 methylhyazine의 축합반응으로 얻은 pyrazolone 1을 Vilsmeier-Haack chloroformylation을 통하여 합성하였다. 2에 nucleophilic aromatic substitution 반응을 하여 질소고리화합물이 5-번 위치에 도입된 pyrazole aldehyde 3a-i를 만든 후, 차레로 oxime 화합물 4a-i 그리고 oxime ether 화합물 6a-i를 각각 합성하였다. 합성된 화합물 중에서 6d는 벼멸구 (Brown Planthopper, BPH), 배추좀나방 (Diamondback Moth, DBM), 점박이응애 (Two Spotted Spider Mite, TSSM)에서 높은 활성을 보여주고 있으며, 이는 fenpyroximate의 살충활성과 비슷하였다. 본 결과는 6d가 다양한 곤충 및 응애에 대하여 효과가 우월하여 살충, 살비제로써 개발 가능성을 보여주고 있다.

• 대한화학회지
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• 제11권2호
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• pp.45-50
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• 1967

有機할로겐化合物의 分離方法으로써 試料의 中性子照射에 依한 放射化 Thin Layer Chromatography를 Methanol을 展開溶媒로 하여 硏究한 結果 各種 할라이드, 할로겐酸, 할로겐알데하이드 等에서 銳敏한 展開 peak를 얻었으며 混合物의 展開에서도 定性確認에 充分한 分離 peak를 얻었다. 多 할로겐化合物, 芳香核鹽化物에 있어서는 試料의 中性子線 照射에 依하여 한 個 以上의 放射化할로겐化合物이 生成되어 確認이 困難하였으며 其他 할로겐 化合物에서는 再現性있는 Rf値를 얻을 수 있었다. 그리고 實驗方法을 記述하고 本 方法의 有用性에 關하여 論議하였다.