• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1218-1242
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• 2002

Photochemical reactions of aromatic carbonyl compounds with silyl ketene acetals have been explored. Irradiation of acetonitrile or benzene solutions containing aryl aldehydes or ketones in the presence of silyl ketene acetals is observed to promo te formation of ${\beta}-hydroxyester$, 2,2-dioxyoxetane and 3,3-dioxyoxetane products. The ratios of these photoproducts, which arise by competitive single electron transfer (SET) and classical Paterno-Buchi mechanistic pathways, is found to be dependent on the degree of methyl-substitution on the vinyl moieties of the ketene acetals in a manner which reflects expected alkyl substituent effects on the oxidation potentials of these electron rich donors. An analysis of the product distribution arising by irradiation of a solution containing butyrophenone (6) and the silyl ketene acetal 9, derived from methyl isobutyrate, provides an estimate of the rate constants for the competitive Norrish type Ⅱ, SET and Paterno-Buchi processes occuring. Finally, sequences involving silyl ketene acetal-aryl aldehyde or ketone photoaddition followed by 2,2-dioxyoxetane hydrolysis represent useful procedures for Claisen-condensation type, ${\beta}-hydroxyester$ synthesis.

• Asian Journal of Atmospheric Environment
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• 제12권2호
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• pp.127-138
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• 2018

This study measured indoor and outdoor levels of hydrocarbon volatile organic compounds (VOCs), such as benzene, toluene, ethylbenzene, and xylene isomers (collectively referred to as BTEX), as well as 13 carbonyl compounds, at 20 homes in Seoul, South Korea. Along with the sampling of BTEX and carbonyls, indoor concentrations of the air pollutants nitrogen oxide (NO) and carbon dioxide ($CO_2$) were also measured at each home. These measurements were used to understand the characteristics of BTEX and carbonyls by calculating the various ratios and correlation coefficients between measured contaminant levels. We found that carbonyls were mostly originated from indoor sources, while BTEX were originated from both indoor and outdoor sources. A high correlation between indoor levels of NO and BTEX indicated that traffic emissions were also an important sources of BTEX.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3914-3922
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• 2011

3-Chloro-1-benzothiophene-2-carbonyl chloride 1 was reacted with glycine in acetone to give 3-chloro-1-benzothiophen-2-yl-carbonylaminoacetic acid 2. Various aldehydes on treatment with compound 2 in acetic anhydride to gave 1,3-oxazol-5-ones 3a-d. These oxazolones was treated with aromatic amines or hydrazides to get various imidazol-4-ones 4a-t or 5a-l. Oxazolones 3a-d was also treated with aromatic hydrazines, expansion of five member oxazole ring to six member triazine ring occurs to yield 1,2,4-triazin-6-ones 6a-h. The structures of all the synthesized compounds were confirmed by spectral data and had been screened for antibacterial activity.

• 한국식생활문화학회지
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• 제9권2호
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• pp.131-136
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• 1994

한국산 씀바귀(Lactuca dentata Makino)의 ethylacetate 추출물에서 6 종류의 flavonoid 성분이 TLC에 의해서 검출 되었으며, 이들은 극성에 따라서 A에서 F가지 명명되었다. 그들 중 주성분으로 생각되는 물질 E를 column chromatography을 이용하여 분리정제 하였다. 물질 E의 녹는 점은 $249.5^{\circ}C-251^{\circ}C$ 로 나타났으며, 그 구조를 밝히기 위하여, 물질 E와 이를 가수분해한 genin에 대한 여러가지 shift reagent에서 UV와 IR분석을 하고 또한 물질 E와 그의 acetyl 유도체에 대한 NMR 분석을 하였으며 물질 E에 결합된 당은 TLC에 의하여 확인하였다. 이와같은 분석 결과에서 물질 E는 luteolin 모핵에 glucose가 결합된 $luteolin-7-0-{\beta}-D-glucoside$로서 확인되었다.

• 한국연초학회지
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• 제29권1호
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• pp.30-40
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• 2007

The objective of this study was to investigate the contribution of various smoke constituents to the toxicological activity of total particulate matter(TPM) or the gas/vapor phase(GVP). These components included phenol compounds, aromatic amines, polycyclic aromatic hydrocarbons, heterocyclic amines, and carbonyl compounds. The mutagenic and cytotoxic potencies were assessed using the Salmonella mutagenicity assay with S. typimurium TA98 strain and the neutral red uptake cytotoxicity assay(NRU) with BALB/c 3T3 fibroblast cells, respectively. The Salmonella mutagenicity test showed that heterocyclic amines exhibited significantly higher levels of toxicity compared to other smoke constituents. Among them, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline(MeIQ) was shown the most mutagenic compound with a specific mutagenicity of $7.9{\times}10^5\;revertants/{\mu}g$. An analysis of the possible contribution revealed that MeIQ account for only 0.85% of the 2R4F-TPM mutagenicity in TA98. NRU data demonstrated that high cytotoxic activity was obtained for hydroquinone, formaldehyde, and acrolein. Based on the results of the present study, the contribution of acrolein to the cytotoxicity of the GVP fraction was calculated as 61%. Thus, a large proportion of the cytotoxic activity of this complex mixture, cigarette smoke gas phase, can be attributed to the acrolein.

• 생명과학회지
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• 제18권11호
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• pp.1570-1577
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• 2008

오만둥이된장찌개의 가열조리에 따른 열유도반응물질을 규명하여 오만둥이를 이용한 가공기술의 기초자료를 제공하고자 향기성분을 분석하였다. 총 128종의 휘발성 향기성분은 에스테르류(16종), 방향족화합물류(14종), 함질소화합물류(11종), 알콜류(34종), 테르펜류(5종), 카르보닐화합물류(23종), 퓨란류(4종), 탄화수소류(13종), 산류(5종) 및 기타화합물류(3종)로 구성되어 있었다. 된장의 향기성분은 방향족화합물, 알콜류 및 산류의 순으로 많았고, 가열 반응 후 pentanoic acid (불쾌취)는 감소하였으며 열유도 화합물인 furfural을 주로 한 퓨란류가 약 2배로 증가하였다. 오만둥이의 향기성분은 decenol, 2,6-dimethylheptanol 및 octanol이 주된 성분인 알콜류, 탄화수소류 및 방향족화합물 순으로 많았다. 가열 반응 후에는 pentanol의 함량이 증가하였고, 함질소아미노산과 카르보닐화합물의 열유도화합물인 2-acetyl-2-thiazoline 및 benzothiazole과 같은 함황고리화합물이 생성되었다. 오만둥이 된장국에서는 오만둥이에서 유리되는 decenol 및 2,6-dimethylheptanol을 주로한 알콜류, 방향족화합물, 탄화수소류 및 된장가열 후 생성된 benzeneacetaldehyde가 주된 카르보닐 화합물이 많았다. 즉 오만둥이 된장국은 독특한 오만둥이향을 함유한 동시에 된장의 구수한 향미를 보유함을 알 수 있었다

• 임산에너지
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• 제17권1호
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• pp.56-70
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• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.

• 생명과학회지
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• 제20권1호
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• pp.113-118
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• 2010

양파추출농축액(오니웰$^{TM}$)의 저장 유통과정 중 품질유지를 위한 척도로서 관능적요소 중 가장 중요한 휘발성 향기성분을 저장기간($30^{\circ}C$, 150일) 동안 분석하였다. 총 23종의 휘발성화합물이 동정되었는데, 이는 함황 화합물류 9종, 카르보닐 화합물류 5종, 퓨란류 4종, 방향족 화합물류 2종 및 기타 화합물류 3종이었다. 함황 화합물류는 전체함량의 80.3~62.6%로 중요한 향기성분임을 알 수 있었다. 이 중 dimethyl trisulfide가 50.1~42.1% 범위로 함황 화합물류 중에서 가장 높은 함량을 차지하였다. 총 함황 화합물류의 함량은 저장기간과 함께 증가하였는데, 특히 신선한 양파향의 dimethyl disulfide와 마늘향의 methyl propyl disulfide 함량이 유의적으로 증가하였다(p<0.05). 가열반응에 의해 생성된 4종의 퓨란류(furfural, 2-acetylfuran, 5-methyl-2-furfural, furfurylalcohol)가 동정되었는데, 함량면에서 함황 화합물 다음으로 많았다(14.2~12.9%). 이 중 furfural이 전체 퓨란류의 61.9~49.4%를 차지하였고, 저장기간과 함께 유의적으로 증가하였다. 카르보닐 화합물에서는 알데히드류가 4종, 케톤 1종으로 총 5종이 검출되었다. 함량면에서는 6.2~4.8% 범위로 퓨란류 다음으로 많았으며, 가열에 의한 지방산화 분해에 의해 생성된 화합물로 동정되었다. 따라서 이들 가열반응에 의해 유도된 퓨란류나 알데히드류가 양파 특유의 함황 화합물과 함께 양파추출농축액(오니웰$^{TM}$)의 풍미에 기여할 것으로 추정되었다.

• 생명과학회지
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• 제21권12호
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• pp.1740-1745
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• 2011

현재 시중에 판매되고 있는 흑양파추출액 3종류(창녕, 무안, 증평 지역산 제품)를 구입하여 관능적 요소 중 가장 중요한 휘발성 향기성분을 분석하여 제품의 품질에 대한 기초자료로 활용하고자 하였다. 시판 흑양파추출액의 휘발성 향기성분을 분석한 결과, 총 51종으로 카르보닐화합물류 15종, 함황화합물류 8종, 방향족화합물류 6종, 퓨란류 6종, 질소화합물류 3종, 알콜류 2종, 산류 2종 및 기타 10종이 검출되었다. 카르보닐화합물 중 2-methylbutanal, 3-methylbutanal, nonanal 및 benzaldehyde가 모든 시료에서 검출되었다. 함황화합물류에서는 dimethyl disulfide와 dimethyl trisulfide가 가장 높은 함량으로 검출되었으며 흑양파추출액의 주요 향기성분에 관여할 것으로 사료되었다. 항산화성을 가지는 thiophene 유도체와 항암효과를 지닌 methylpropyl disulfide, methyl-(Z)-propenyl disulfide 및 methyl-(E)-propenyl disulfide 등은 2 제품(A, B)에서만 검출되었다. 비효소적갈변유도물질인 furfural이 모든 시료에서 높은 함량으로 나타났으며 pyrazine류 및 acetic acid 도 많은 함량으로 검출되어 이들 향기성분들이 시판 흑양파추출액의 휘발성 성분에 특징적인 냄새성분으로 기여할 것으로 사료되었다.