• Plant Biotechnology Reports
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• 제5권2호
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• pp.127-134
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• 2011

The biotransformation potential of cell suspension cultures generated from Withania somnifera leaf was investigated, using withanolides, i.e. withanolide A, withaferin A, and withanone as precursor substrates. Interestingly, the cell suspension cultures showed inter-conversion of withanolides, as well converted to some unknown compounds, released to the culture media. The bio-catalyzed withanolide was detected and quantified by TLC and HPLC, respectively. There is noticeable conversion of withanolide A to withanone, and vice versa though at a lower level. The type of reaction of this biotransformation appears to be substitution of 20-OH group to 17-OH in withanolide A. In this paper, we present for the first time the possibility of biotransformation by inter-conversion of withanolides of pharmacological importance through cell suspension culture of W. somnifera. The possible role of putative cytochrome $P_{450}$ hydroxylases is implicated in the conversion.

• Bulletin of the Korean Chemical Society
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• 제27권3호
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• pp.403-406
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• 2006

The surface structure and electrochemical behavior of self-assembled monolayers (SAMs) formed by aromatic thiols on Au(111) were investigated by scanning tunneling microscopy (STM) and cyclic voltammetry. Benzenethiol (BT) forms disordered phases on Au(111) which are composed of many bright domains, while benzyl mercaptan (BM), with a methylene unit between the aromatic group and sulfur atom, forms twodimensional ordered SAMs on Au(111). In addition, two phase-separated domains consisting of disordered and ordered phases were observed in binary SAMs formed from a 1 : 1 mixed ethanol solution of BT and BM. From STM and CV measurements, we found that the blocking efficiency of aromatic thiol SAMs coated on an Au(111) electrode for an electron transfer reaction decreases as the structural order of the SAMs increases. Molecular-scale STM and CV results obtained here will be very useful in designing functional SAMs for further applications, such as the improvement of corrosion passivation of Au(111) on an aromatic thiolmodified Au(111) surface.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2002년도 봄 학술발표대회 발표논문집
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• pp.209-212
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• 2002

본 연구는 방향족 화합물질 중 페놀폐수에 대한 생물학적 처리를 위해 본 실험실에서 분리한 페놀분해능이 우수한 Rhodococrus sp. EL-GT를 이용하여 catechol 분해 catechol 1,2-dioxygenase 분해활성을 측정하였고, 이것이 ortho-pathway임을 확인할 수 있었다. 또한 다른 연구에서 보고된 Rhodococcus rhodochrous NCIMB 13259 균주의 catechol 1,2 dioxygenase를 기초로한 primer를 이용하여 PCR을 수행하였으며 이 분해 유전자의 cloning실험을 수행 중이다. 이들 실험을 통하여 Rhodococcus sp.의 페놀분해균의 유전적 구조 및 특성을 검토하고 밝혀지는 단백질 정보를 이용하여 방향족 화합물의 분해능이 보다 우수한 균주의 개발을 시도하고자 한다.

• Asian Journal of Atmospheric Environment
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• 제10권2호
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• pp.90-98
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• 2016

Total suspended particulates (TSP) in the atmosphere were collected for 2 weeks during winter in Muroran, Hokkaido, Japan, a typical iron-manufacturing city. The concentrations of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in TSP were determined by high-performance liquid chromatography (HPLC) using fluorescence and chemiluminescence detectors, respectively. No relationship was observed between the atmospheric PAH and NPAH concentration, or the atmospheric PAH and TSP concentration. However, there was a tendency that the atmospheric PAH concentration was higher when the wind blew from the coke-oven plant. Furthermore, the concentration ratios of 1-nitropyrene to pyrene, which is a suitable indicator of the contribution made by automobiles and coal combustion systems to urban air particulates, were smaller in Muroran and the values were close to those observed in particulates from coal combustion systems. Therefore, these results show that the PAH and NPAH compositions for Muroran are characteristic of an iron-manufacturing city.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.330-337
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• 2018

Polycyclic aromatic hydrocarbons (PAHs), including naphthalene, are widely distributed in nature. Naphthalene has been regarded as a model PAH compound for investigating the mechanisms of bacterial PAH biodegradation. Pseudomonas sp. AS1 isolated from an arseniccontaminated site is capable of growing on various aromatic compounds such as naphthalene, salicylate, and catechol, but not on gentisate. The genome of strain AS1 consists of a 6,126,864 bp circular chromosome and the 81,841 bp circular plasmid pAS1. Pseudomonas sp. AS1 has multiple dioxygenases and related enzymes involved in the degradation of aromatic compounds, which might contribute to the metabolic versatility of this isolate. The pAS1 plasmid exhibits extremely high similarity in size and sequences to the well-known naphthalene-degrading plasmid pDTG1 in Pseudomonas putida strain NCIB 9816-4. Two gene clusters involved in the naphthalene degradation pathway were identified on pAS1. The expression of several nah genes on the plasmid was upregulated by more than 2-fold when naphthalene was used as a sole carbon source. Strains have been isolated at different times and places with different characteristics, but similar genes involved in the degradation of aromatic compounds have been identified on their plasmids, which suggests that the transmissibility of the plasmids might play an important role in the adaptation of the microorganisms to mineralize the compounds.

• 한국연초학회지
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• 제28권2호
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• pp.152-157
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• 2006

A new procedure has been developed for the quantitation of aromatic amines in mainstream cigarette smoke. Two solid-phase extraction (SPE) clean up steps, using a different retention mechanisms, are required to process the samples. The first step used a cation-exchange cartridge, followed by a second step that used a cartridge with a hydrophobic retention character. The aromatic amines eluted from the second SPE cartridge are derivatized with pentafluoropropionic anhydride. This new method have advantages over other reported techniques, being sensitive, robust, and easily automated. The detection limits were ranged from 0.12 ng/mL for 1-aminonaphthalene to 0.16 ng/mL for 3-aminobiphenyl and the recoveries were from 97 to 106%. Compared with other reports for analysis of 2R4F reference cigarette, this method shows a close analytical data and good repeatability.

• 한국수소및신에너지학회논문집
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• 제8권3호
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• pp.131-135
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• 1997

방향족 니트로 화합물들을 10 % Palladium 촉매 존재 하에서 벤젠 용액에서 45 psi의 압력을 가지고 실온에서 수소첨가 반응시켜서 방향족 아민들을 얻었다. 본 연구에서는 방향족 니트로 화합물로써 nitrobenzene-$d_5$, $^{15}N$-nitrobenzene, 그리고 4'-nitrobenzo-15-crown-5를 이용하여 수소첨가 반응을 통하여 방향족 아민들을 합성하였다. 적외선 흡수 스펙트럼에서 수소첨가 반응으로부터 얻어진 아민에서 특성적인 N-H 신축 진동이 3450과 $3350cm^{-1}$에서 나타났다. 연구결과 수소첨가 촉매 반응에 의하여 방향족 아민 화합물을 제조할 때는 수득률이 양호하고 부 생성물의 생성이 크지 않아 다른 방법으로는 쉽게 제조할 수 없는 방향족 아민 화합물을 상업적으로 제조할 수 있음을 보여주고 있다.

• Journal of the Korean Wood Science and Technology
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• 제25권1호
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• pp.1-7
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• 1997

Kraft oak lignin and ricestraw lignin from acetosolve pulping were dissolved in 50/50 mixture of tetralin/m-cresol solvent. The dissolved lignin was reacted in the pressurized autoclave which was operating at $350{\sim}500^{\circ}C$ of reaction temperature and 10~20 atms of reaction pressure respectively_Hydrogen pressure of 60~80kg/$cm^2$ was exercising into the pressurized autoclave reactor to create thermochemical hydrogenolysis reaction. It was identified by GLC, GC-MS and HPLC that the alkyl-aryl-${\beta}$-O-4 ether bond of lignin was cleaved and degraded into various smaller molecules of aromatic compound such as phenols and cresols under the reaction conditions around $300^{\circ}C$ and 10 atms of reaction temoerature and pressure. Hydrogenolysis reaction of lignin compound which was done above $500^{\circ}C$ of reaction temperature and 20 atms of reaction pressure showed that the amount of aromatic compound such as phenols and cresols degraded from reactant lignin was decreasing with newly present and increasing water out of product mixtures. It was supposed that new aliphatic compound of high molecular weight hydrocarbon is composed due to higher reaction temperature and pressure of hydrogenolysis reaction such as $500^{\circ}C$ and 20 atms, even though it was almost impossible, to identify what kind of degraded products it was by HPLC.

• Journal of Plant Biotechnology
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• 제33권2호
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• pp.111-115
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• 2006

Rot 3 유전자로 형질전환된 들깨를 이용하여 aromatic compounds, brightness, 안토시아닌 함량, leaf index를 조사하여 모본과의 품질적인 차이가 있는가를 조사하여 형질전환체의 안정성을 확보하기 위한 연구이다. Rot 3 유전자는 T1 과T2 세대에서 유전자발현이 되었으며, 형질전환이 확인된 개체는 주요 농업형질이 형질전환 되지 않은 들깨와는 차이가 없는 것으로 나타났다. 또한 aromatic compounds와 leaf brightness도 차이를 나타내지 않았다. 그러나 leaf index는 유전자의 표현을 나타내어 형질전환체와 형질전환되지 않은 들깨잎의 모양은 차이가 나타났다.

• Advances in environmental research
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• 제3권4호
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• pp.293-306
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• 2014

The present study primarily focuses on the evaluation of the comparative effect of chemical coagulation and ultrasonication for elimination of aromatic amines (AAs) present in anaerobically pretreated textile wastewater containing different types of dyes including azo dyes. Color and COD reduction was also monitored at the optimized conditions. The production of AAs was measured spectrophotometrically in the form of total aromatic amines (TAAs) and also verified with high performance liquid chromatography (HPLC) selectively. A composite coagulant, magnesium chloride (MC) aided with aluminium chlorohydrate (ACH) in an equal ratio (MC + ACH) was utilized during the coagulation process, which yielded 31% of TAAs removal along with 85% of color and 52% of COD reduction. At optimized power (200 W) and sonication time (5 h), an appreciable TAAs degradation efficiency (85%) was observed along with 51% color reduction and 62% COD removal using ultrasonication. The chromatographic data indicate that sulphanilic acid and benzidine types of aromatic amines were produced after the reductive cleavage of utilized textile dyes, which were effectively mineralized after ultrasonication. The degradation followed the first order kinetics with a correlation coefficient ($R^2$) of 0.89 and a first-order kinetic constant (k) of $0.0073min^{-1}$.