• Title/Summary/Keyword: Carboxyl group

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Chemical Structures of Lignin by Infrared Spectroscopy - Assignment of Infrared Absorption Bands in Lignin Compounds - (IR Spectra에 의(依)한 리그닌의 화학구조(化學構造) - 단(單), 삼량체(三量體) 리그닌화합물(化合物)의 흡수대귀속(吸收帶歸屬) -)

  • Hwang, Byung-Ho
    • Journal of the Korean Wood Science and Technology
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    • v.11 no.3
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    • pp.58-69
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    • 1983
  • This research is performed to compare lignin compounds isolated in Pinus koraiensis Sieb et Zucco, with those compounds which have been already isolated. and to elucidate IR spectra of functional groups and aromatic nucleus for chemical structure of lignin. In vanillin and dehydrodivanillin having carbonyl group ill ${\alpha}$-position. characteristic absorption band of carbonyl group was confirmed in 1665 $cm^{-1}$. Absorption band of vanillic and syringic acid with carboxyl group were indicated in 1675 and 1690 $cm^{-1}$ respectively. Syringic acid showed low wave number because this was affected by methoxyl group. Characteristic absorption bands of guaiacyl, syringly and guaiacyl-syringyl co-polymer nucleus were clearly disclosed in diarylpropane compounds. It were reconfirmed that absorption band of guaiacyl showed longer wave number than of syringly nucleus.

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Biological Activity of Multifunctional Oligopeptide Derivatives

  • Kim, Bo Mi
    • Journal of Integrative Natural Science
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    • v.9 no.2
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    • pp.86-93
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    • 2016
  • The peptide sequences, GHK(Gly-His-Lys) and KTTKS(Lys-Thr-Thr-Lys-Ser), using a collagen stimulator recently were manipulated at N-terminal as a multifunctional peptide derivative with PEG(polyethyleneglycol) linker connected to gallic acid which presents anti-inflammatory activity. The multifunctional peptide derivatives were obtained in a normal peptide preparation method through SPPS(solid phase peptide synthesis) using Fmoc chemistry and a carboxyl group insertion reaction of PEG-3,4,5-triacetoxy benzoate by using potassium tert-butoxide and ethyl bromoacetate, which was separated by Sephadex DEAE. It gave a good compromise to a cosmetic application for cell cytotoxicity, anti-wrinkle, and anti-inflammation.

Controlled Growth of Layered Silver Stearate on 2D and 3D Surfaces

  • Lee, Seung-Joon;Han, Sang-Woo;Kim, Kwan
    • ETRI Journal
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    • v.25 no.6
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    • pp.517-522
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    • 2003
  • This investigation confirms that silver stearate consists of an infinite-sheet, two-dimensional, nonmolecular layered structure. Scanning electron microscopy, X-ray diffraction, and infrared spectroscopy reveal the following: plate-like morphology is identified from the SEM image, XRD peaks can be indexed to the (0k0) reflections of a layered structure, and infrared peaks show that alkyl chains are present in an all-trans conformational state with little or no significant gauche population. Based on these structural characteristics, we demonstrate that silver stearate, a prototype of layered organic-inorganic hybrid material, can be grown not only in a designed two-dimensional pattern but also in three-dimensionally ordered ways by using carboxyl-group terminated nanoparticles as a template.

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Enzymatic synthesis of sugar esters of L-lysine and L-aspartic acid

  • Jeon, Gyu-Jong;Park, O-Jin;Sin, Mun-Sik;Yang, Ji-Won
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.646-647
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    • 2001
  • The enzymatic synthesis of conjugates of lysine and aspartic acid with D-glucose was studied. Optimase M-440 showed the very poor regioselectivity in the transesterification of $N{\alpha}$,$N'{\varepsilon}-di-t-Boc-L-Lys-OTFE$ and N-t-Boc-L-Asp-diOTFE with D-glucose. The acylation of glycosidic -OH and primary -OH of D-glucose occurred. However, Optimase M-440 catalyzed only the acylation of primary -OH group in the transesterification of $N{\alpha}$,$N'{\varepsilon}-di-t-Boc-L-Lys-OTFE$ and N-t-Boc-L-Asp-diOTFE with ${\alpha}-$ and ${\beta}-methylglucopyranoside$ in high yields without any other transesterification. Optimase M-440 also discriminated carboxyl groups of N-t-Boc-L-Asp-diOTFE.

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Stabilization of Subtilisin Carlsberg in Polar Organic Solvents by Chemical Modification (화학적 변환에 의한 Subtilisin Carlsberg의 극성 유기용매에서의 안정성 향상)

  • 류근갑
    • KSBB Journal
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    • v.11 no.2
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    • pp.186-192
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    • 1996
  • The effects of chemical modification on the enzymes' stability in polar organic solvents were studied with subtilisin Carlsberg in dimethylformamide-water mixtures as a model system. Three out of nine lysine residues of subtilisin Carlsberg were coupled to either trimellilic or pyromellitic anhydrides thereby, for each lysine residue modified, resulting in the net replacement of one basic amino group by two or three acidic carboxyl groups, respectively. In water at 60$^{\circ}C$, both trimellitic and pyromellitic anhydride-modified subtilisin Carlsberg showed increased thermostability by 2.6 times and 1.6 times, respectively, as compared to that of unmodified enzyme. In 70% dimethylformamide at 25$^{\circ}C$, however, only pyromellitic acrid was shown to enhance the stability of subtilisin Carlsberg by 5.5 times increasing the half life time of irreversible inactivation from 4.9hr for unmodified enzyme to 27.8hr for modified enzyme.

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HPLC Determination of Carboxyl Group Using 2-Bromoacetyltriphenylene as a Pre-labeling Reagent - Separative determination of bile acids by HPLC (2-Bromoacetyltriphenylene 유도체화제를 이용한 카르복실기 함유 성분의 분석법 (II) - 담즙산 혼합물의 HPLC에 의한 분리정량)

  • 박만기;정해수;양호길
    • YAKHAK HOEJI
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    • v.31 no.2
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    • pp.105-111
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    • 1987
  • A high performance liquid chromatographic method was developed for the simultaneous determination of free and glycine conjugated bile acids. Free and glycine conjugated bile acids were extracted from bear gall bladder by methanol and from serum using a Sep-pak $C_{18}$ catridge. The extracted bile acids were labeled with 2-bromoacetyltriphenylene in acetonitrite using 18-crown-6-ether as a catalyst. Derivatized bile acids were separated from the individual bile acids on a reversedphase column (Chemcosorb 5-ODS-H) using acetonitrile-methanol-water(10:50:30) as a mobile phase and monitored by an UV-detector at 254nm. Linearities of calibration curve were obtained between 4 ng and 24 ng, and recoveries from bear gall bladder sample were higher than 94%.

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UV-Cut Effects of Cotton Fabrics Treated with UV Absorbents (자외선 흡수제 처리에 의한 면직물의 자외선 차단 효과)

  • 지영숙;김상희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.5
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    • pp.622-627
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    • 1994
  • The purpose of this study is to investigate the adsorption rate, adsorption quantities and the UV-Cut effects of cotton fabrics treated with several UV absorbents. The result of this study were as follows: cotton fabric treated with 2,2'-dihydroxy-4- methoxy-benzophenone shows more efficient than ones treated with 4-aminobenzoic acid and 2·hydroxy-1, 4-naphthoquinone in UV absorption. This may be due to the absorption of UV light by formation of intra moleculaar hydrogen bond. The formation of hydrogen bonds between hydrogen atoms of two hydroxy groups and one oxygen atom of carboxyl group in 2, 2'-dihydroxy-4-methoxy-benzophenone would be easier than that of the other absorbents. The adsorption isotherms of 4-aminobenzoic acid and 2-hydroxy-1, 4-naphthoquinone were similar to Freundlich type, while that of 2, 2'-Dihydroxy-4-methoxy-benzophenone was Henry type. Cotton fabrics treated with Antifade MC-100 and W Cut I-2 were just alike in UV absorption, but Antifade 8001 was inferior to the others.

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Involvement of Electrostatic Interactions between the Components of Toluene Dioxygenase from Pseudomonas putida Fl

  • Lee, Kyoung
    • Journal of Microbiology and Biotechnology
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    • v.8 no.4
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    • pp.416-421
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    • 1998
  • A carboxyl group modifier, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) was used to study the interactions between three components of toluene dioxygenase (TDO) from Pseudomonas putida FI. $Ferredoxin_{TOL}$ activity was increased by the treatment with EDC; however, the activity was rapidly declined in the prolonged incubation. In covalent cross-linking experiments with EDC, $Ferredoxin_{TOL}$ made a one-to-one complex with $Reductase_{TOL}$ or the large subunit of $ISP_{TOL}$. These results provide evidence for the involvement of electrostatic interactions in the TDO electron transfer system.

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오존에 의한 토양유기물질의 구조적 변화 특성

  • 정해룡;배기진;최희철
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.45-48
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    • 2001
  • The packed column experiments were conducted with a field soil, collected directly from the aquifer located at Bonchon industrial complex in K-city in order to characterize SOM reaction with ozone and to delineate the transformation of water soluble SOM after ozonation. As reaction time increased, water soluble organic matter increased, and this organic matter was in the range of 500∼1000 dalton. pH of extractants decreased with the increase of ozonation time. This Is because aromtic compounds in SOM were oxidized and carboxylic acid groups were formed. From the FT-IR spectra, the content of carboxylate increased as ozone injection time increased and hydroxyl group, which represents phenolic and alcoholic hydroxyl groups decreased. This is because oxidative ring fission formed carboxyl acid groups. This result provides a good agreement with pH decrease.

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Properties of Biodegradable Polymer and Afforestation Seedling Mulching Mat (생분해성 고분자와 멀칭매트의 물성)

  • Kim, Kang-Jae;Kim, Hyoung-Jin;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.2
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    • pp.75-81
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    • 2010
  • Characteristics of mixing biodegradable polymers and polymer impregnated paper for mulching mat for seedling were investigated. The mixed film of 70% PLA was most easily biodegradable. The surface of polymer films were changed to more rough due to enzymatic degradation of lipase. Tensile strength and breaking elongation of PLA mixed films were increased to the 0.04-0.31 kN/m and the 0.17-0.96%, respectively. With higher PLA contents, intensities of ester originated carboxyl group(about $1,748cm^{-1}$) were increased. Physical properties of prepared mulching mats were increased with PLA contents and stiffness of mulching mat was not so much changed.