• Title/Summary/Keyword: aromatic

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Expert System Approach for Vapor-Phase Infrared Spectra of Aromatic Compounds

  • Pyo Dongjin;Hwang Hoon;Lee Junyeoun
    • Bulletin of the Korean Chemical Society
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    • v.13 no.2
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    • pp.148-155
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    • 1992
  • Computerized interpretation of vapor phase infrared spectra using a novel expert system approach for spectra/structure correlation for vapor phase spectra is introduced. Rapid identification of aromatic functional groups of components in gaseous mixture can be achieved using this expert system.

Biosynthetic pathway of shikimate and aromatic amino acid and its metabolic engineering in plants (식물에서 shikimate 및 방향족 아미노산 생합성 경로와 이의 대사공학적 응용)

  • Lim, Sun-Hyung;Park, Sang Kyu;Ha, Sun-Hwa;Choi, Min Ji;Kim, Da-Hye;Lee, Jong-Yeol;Kim, Young-Mi
    • Journal of Plant Biotechnology
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    • v.42 no.3
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    • pp.135-153
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    • 2015
  • The aromatic amino acids, which are composed of $\small{L}$-phenylalanine, $\small{L}$-tyrosine and $\small{L}$-tryptophan, are general components of protein synthesis as well as precursors for a wide range of secondary metabolites. These aromatic amino acids-derived compounds play important roles as ingredients of diverse phenolics including pigments and cell walls, and hormones like auxin and salicylic acid in plants. Moreover, they also serve as the natural products of alkaloids and glucosinolates, which have a high potential to promote human health and nutrition. The biosynthetic pathways of aromatic amino acids share a chorismate, the common intermediate, which is originated from shikimate pathway. Then, tryptophan is synthesized via anthranilate and the other phenylalanine and tyrosine are synthesized via prephenate, as intermediates. This review reports recent studies about all the enzymatic steps involved in aromatic amino acid biosynthetic pathways and their gene regulation on transcriptional/post-transcriptional levels. Furthermore, results of metabolic engineering are introduced as efforts to improve the production of the aromatic amino acids-derived secondary metabolites in plants.

Studies on the Environmental Condition, the Search and the Response to Temperature and Photoperiods of the Plants for Urban Forest Aromatic Bath (도시형(都市型) 삼림욕장(森林浴場)의 환경(環境), 욕장식물(浴場植物)의 탐색(探索)과 온도(溫度) 및 광주기(光週期) 반응(反應))

  • Hong, Sung Gak;Kang, Byoung Keun;Im, Hyoung Tak;Son, Yo Whan;Kim, Jong Jin
    • Journal of Korean Society of Forest Science
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    • v.88 no.4
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    • pp.523-532
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    • 1999
  • The studies were carried out to develop an urban forest aromatic bath in the idle space within city area for handicapped persons, patients and city workers, who having less chance to visit the natural forest aromatic bath. The environmental conditions were checked in the experimental double vinyl house where native and exotic aromatic woody and herbaceous plants were growing with minimum energy input in the periods of mid-winter and mid-summer. The growth and photoperiodic responses of the plants to the low and high temperatures were observed during winter and summer respectively. The most of herbaceous plants in the double vinyl house with the controlled minimum night temperature of $-2^{\circ}C$ had no winter injury but did not grow and started the growth in April. The exotic herbs such as Catnip faassen's(Nepeta x faassenia) and Lemon bergamot(Monarda citriodora) grew better in the longer photoperiodic conditions. The growth rates of Abies koreana, Thuja koraiensis and Pinus sylvestriformis in the early spring were affected mainly by the night minimum temperature and less affected by the photoperiodic conditions during winter. The native aromatic herbs such as Robdosia japonica, Molsa punctulata, Agastache rugosa and Codonopsis lanceolata showed stimulatory growth at the 16 hours day-length in case of the high temperature vinyl hose. The height and root collar diameter growth of pine seedlings were inhibited in maxim temperatures over $40^{\circ}C$ during summer.

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Volatile Organic Compounds contamination in some urban runoff and groundwater samples in Seoul City (서울시 도로변 빗물과 지하수의 VOCs오염)

  • 이평구;박성원;전치완;신성천
    • Journal of Soil and Groundwater Environment
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    • v.6 no.3
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    • pp.73-91
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    • 2001
  • compounds (VOCs) were selected for assessment of VOCs contamination in some urban runoff and groundwater samples in Seoul. They included 3 aromatic hydrocarbons, 13 alkyl benzenes, 1 ether, 26 halogenated alkanes, 10 halogenated alkenes, and 9 halogenated aromatics. The levels of VOCs in urban runoff and groundwater were measured for samples collected in March 2000, June 2000 and November 2000 in Seoul City. A total of 78 samples (44 run-off water, 27 groundwater, and 7 samples from 4 urban wastewater treatment plants in Seoul) were collected and analysed by GC-MS with purge and trap. After examination of the runoff, it was concluded that alkyl benzenes and aromatic hydrocarbons were organic compounds which were significantly impacted by traffic flows in Seoul. Of 62 VOCs, only 11 VOCs were not detected in runoff samples, while 14 VOCs were detected in 27 groundwater samples. The toluene content in the runoff was extremely variable from 0.1ppb to 29,310ppb, depending on the different sampling sites. The concentrations of xylene ranged between 0.07ppb and 2970ppb in the runoff. The concentrations ranged from 0.05ppb to 33.0ppb for benzene, 0.05ppb to 960ppb for ethylbenzene, 0.08ppb to 20ppb for trichloromethane (chloroform) , 0.03ppb to 4.30ppb for trichloroethylene(TCE) and 0.1ppb to 50ppb for 1,1,2-trichloroethane. From the preliminary study of groundwater from some wells in Seoul, the most frequently detected VOCs are djchlorornethane(methylene chloride), trichloromethane(chloroform) and toluene. Most of aromatic hydrocarbons, alkyl benzenes and other solvents generally lower than detection limits.

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Streptomycetes Inducible Gene Cluster Involved in Aromatic Compound Metabolism

  • Park, Hyeon-Ju;Kim, Eung-Su
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.422-427
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    • 2003
  • Streptomyces setonii (ATCC 39116) is a Gram-positive thermophilic soil actinomycetes capable of degrading single aromatic compounds including phenol and benzoate via ortho-cleavage pathway. we isolated approximately 6.3-kb S. setonii DNA fragment containing a thermophilic catechol 1,2-dioxygenase(C12O) gene. Here we further revealed that the 6.3-kb S. setonii DNA fragment was organized into two putative divergently-transcribed clusters with 6 complete and one incomplete open reading frames (ORFs). The first cluster with 3 ORFs showed significant homologies to previously known benA, benB, and benC, implying a part of benzoate catabolic operon. The second cluster revealed an ortho-cleavage catechol catabolic operon with three translationally-coupled ORFs (catR, catB, catA). Each of these individually-cloned ORFs was expressed in E. coli and identified as a distinct protein band with a theoretical molecular weight in SDS-PAGE. The expression of the cloned S. setonii catechol operon was induced in a heterologous S. lividans by specific single aromatic compounds including catechol, phenol, and 4-chlorophenol. The simitar induction pattern was also observed using a luciferase gene-fused reporter system, implying that S. setonii employs an inducer-specific regulatory mechanism for aromatic compound metabolism.

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Synthesis of Polyimides Derived from 2,2-Bis[4-(4-aminobenzoyl)phenoxy]hexafluoropropane and Aromatic Dianhydrides (2,2-Bis[4-(4-nitrobenzoyl)phenoxy]hexafluoropropane과 방향족 이무수물을 사용한 폴리이미드의 합성)

  • Park, Jung Hye;Ahn, Byung Hyun
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.50-55
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    • 2016
  • Aromatic diamines containing hexafluoroisopropylidene and ester moiety were synthesized from 4,4'-hexafluoroisopropylidene diphenol and nitrobenzoyl chloride. The reaction of aromatic diamines with hexafluoroisopropylidene phthalicdianhydride (6FDA) or pyromellitic dianhydride (PMDA) gave four kinds of poly(amic acid)s. Their inherent viscosities ranged from 0.196 to 0.346 dL/g. Poly(amic acid)s were converted to polyimides by thermal imidization. The glass transition temperatures ($T_g$) of polyimides were between 241 and $289^{\circ}C$. The 5% weight loss temperatures were recorded in the range of $430{\sim}492^{\circ}C$. The tensile strength of polyimide films were measured as 29.84~64.38 MPa.