• Title/Summary/Keyword: thiol group

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Anchoring Cadmium Chalcogenide Quantum Dots (QDs) onto Stable Oxide Semiconductors for QD Sensitized Solar Cells

  • Lee, Hyo-Joong;Kim, Dae-Young;Yoo, Jung-Suk;Bang, Ji-Won;Kim, Sung-Jee;Park, Su-Moon
    • Bulletin of the Korean Chemical Society
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    • v.28 no.6
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    • pp.953-958
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    • 2007
  • Anchoring quantum dots (QDs) onto thermodynamically stable, large band gap oxide semiconductors is a very important strategy to enhance their quantum yields for solar energy conversion in both visible and near-IR regions. We describe a general procedure for anchoring a few chalcogenide QDs onto the titanium oxide layer. To anchor the colloidal QDs onto a mesoporous TiO2 layer, linker molecules containing both carboxylate and thiol functional groups were initially attached to TiO2 layers and subsequently used to capture dispersed QDs with the thiol group. Employing the procedure, we exploited cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) as inorganic sensitizers for a large band gap TiO2 layer of dye-sensitized solar cells (DSSCs). Their attachment was confirmed by naked eyes, absorption spectra, and photovoltaic effects. A few QD-TiO2 systems thus obtained have been characterized for photoelectrochemical solar energy conversion.

Quality Indexes for the Evaluation of Cigarette Smoke. (담배연기의 평가를 위한 새로운 계수)

  • 신영국;노동석;유광근
    • Journal of the Korean Society of Tobacco Science
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    • v.3 no.2
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    • pp.123-128
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    • 1981
  • For evaluating the cigarette smoke quality of nonblended and commercial cigarettes, four modified smoke quality indexes were deduced from considering the reactivity of the thiol group in cystine (SH value) with the cigarette smoke constituents, and from the maximum limited contents of tar. nicotine, and carbon monoxide for the less harmful cigarettes. These results were discussed with respect to correlation coefficients between the indexes and tar/nicotine ratio which had been known reliable for smoke quality evaluation. Among the three indexes, the SH/[(N/O.6) +($\frac{C+T}{8}$)] index was found to be the most reliable and applicable.

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Bifunctional Group Participated Nitrile Group Hydrolyzing Enzyme Model Systems: Hydrolysis of the Nitrile Group of $\alpha$-Aminophenylacetonitrile to Phenylglycineamide and Phenylglycine by Various thiol Compounds

  • Lee, Young-Bok;Goo, Yang-Mo;Lee, Jae-Keun
    • Archives of Pharmacal Research
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    • v.11 no.4
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    • pp.285-291
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    • 1988
  • 2-mercaptoethanol, thioglycolic acid, glutathione, 3-mercapto-1, 2-propanediol and 3-mercapto-2-butanol showed catalytic activities on the hydrolysis of $\alpha$-amino-phenylacetonitrile to phenylglycineamide at the rate of 12.19 $\times$ $10^{-2}$, 8.03 $\times$ $10^[-2}$, 6.83 $\times$ $10^{-2}$, 8.60 $\times$ $10^{-2}$ and 6.04 $\times$ $10^{-2}$ mM $min^{-1}$, respectively. hte hydrolysis rate was faster in buffer than in water. The hydrolysis of the nitrile compound to phenylglycine was limited.

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Thymoquinone Prevents Myocardial and Perivascular Fibrosis Induced by Chronic Lipopolysaccharide Exposure in Male Rats - Thymoquinone and Cardiac Fibrosis -

  • Asgharzadeh, Fereshteh;Bargi, Rahimeh;Beheshti, Farimah;Hosseini, Mahmoud;Farzadnia, Mehdi;Khazaei, Majid
    • Journal of Pharmacopuncture
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    • v.21 no.4
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    • pp.284-293
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    • 2018
  • Objectives: Thymoquinone (TQ) is one of the active ingredients of herbal plants such as Nigella sativa L. (NS) which has beneficial effects on the body. The beneficial effects of TQ on the cardiovascular system have reported. This study aimed to investigate the effect of TQ on cardiac fibrosis and permeability, serum and tissue concentration of inflammatory markers and oxidative stress status in chronic lipopolysaccharide exposure in male rats. Methods: Seventy male Wistar rats were randomly divided into five groups as follows: (1) control; (2) LPS (1 mg/kg/day); (3-5) LPS + TQ with three doses of 2, 5 and 10 mg/kg (n=14 in each group). After 3 weeks, serum and cardiac levels of $IL-1{\beta}$, $TNF-{\alpha}$ and nitric oxide (NO) metabolites, and cardiac levels of malondialdehyde (MDA), total thiol groups, catalase (CAT) and superoxide dismutase (SOD) activities, permeability of heart tissue (evaluated by Evans blue dye method) and myocardial fibrosis were determined, histologically. Results: LPS administration induced myocardial and perivascular fibrosis and increased cardiac oxidative stress (MDA), inflammatory markers and heart permeability, while, reduced anti-oxidative enzymes (SOD and CAT) and the total thiol group. Administration of TQ significantly attenuated these observations. Conclusion: TQ improved myocardial and perivascular fibrosis through suppression of chronic inflammation and improving oxidative stress status and can be considered for attenuation of cardiac fibrosis in conditions with chronic low-grade inflammation.

Relationship between Chemical Structure and Antimicrobial Activities of Isothiocyanates from Cruciferous Vegetables against Oral Pathogens

  • Ko, Mi-Ok;Kim, Mi-Bo;Lim, Sang-Bin
    • Journal of Microbiology and Biotechnology
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    • v.26 no.12
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    • pp.2036-2042
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    • 2016
  • We evaluated the potentials of 10 isothiocyanates (ITCs) from cruciferous vegetables and radish root hydrolysate for inhibiting the growth of oral pathogens, with an emphasis on assessing any structure-function relationship. Structural differences in ITCs impacted their antimicrobial activities against oral pathogens differently. The indolyl ITC (indol-3-carbinol) was the most potent inhibitor of the growth of oral pathogens, followed by aromatic ITCs (benzyl ITC (BITC) and phenylethyl ITC (PEITC)) and aliphatic ITCs (erucin, iberin, and sulforaphene). Sulforaphene, which is similar in structure, but has one double bond, showed higher antimicrobial activity than sulforaphane. Erucin, which has a thiol group, showed higher antimicrobial activity than sulforaphane, which has a sulfinyl group. BITC and iberin with a short chain exhibited higher antimicrobial potential than PEITC and sulforaphane with a longer chain, respectively. ITCs have strong antimicrobial activities and may be useful in the prevention and management of dental caries.

Effect of Ampelopsis radix on the Toxicity of Adriamycin (Adriamycin의 독성 발현에 미치는 백렴(Ampelopsis radix)의 영향)

  • Kim, Dong-Seok;Lee, Seong-Ho;Jeong, Yeon-Bong
    • The Korean Journal of Food And Nutrition
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    • v.7 no.3
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    • pp.232-238
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    • 1994
  • Adriamycin is a major cancer chemotherapeutic agent against a me range of human neoplasms. However, its clinical application is limited since It has a variety of side effects, bone marrow suppression and cardiotoxity, and this toxicity appears by free radical. This study investigated the effect of Ampelopsis radix on the toxicity of adriamycin. The methanol fraction reduced slightly adriamycin induced lipid peroxidation and superoxide production at the dose of 50mg /kg. 1.p., respectively. During the adriamycin administration. Protein bound-SH, nonprotein bound-SH, and glutathione-5-transferase did not change, but methanol fraction treated group were markedly increase. These results indicated that Ampelopsis radix has a major influence on the thiol group and related enzyme activity on the antioxidative effects.

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Subunit Organization of Bacterial Malonate Decarboxylases: The Smallest ${\delta}$ Subunit as an Acyl-Carrier Protein

  • Byun, Hye-Sin;Kim, Yu-Sam
    • BMB Reports
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    • v.30 no.2
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    • pp.132-137
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    • 1997
  • In order to compare molecular structure, malonate decarboxylases from Acinetobacter calcoaceticus, Pseudomonas fluorescens, and Pseudomonas putida aerobically grown on malonate, were purified by the method employing streptomycin sulfate treatment, chromatography with PBE 94 and ${\omega}-aminohexyl$ agarose. Molecular masses were estimated to be 185, 200, and 200 kDa, respectively. All malonate decarboxylases were multimeric enzymes consisting of four different subunits, $2{\alpha},\;1{\beta},\;1{\gamma},\;and\;1{\delta}$. The molecular masses of the Pseudomonas enzyme subunits were $65({\alpha})$, $33({\beta})$, $30({\gamma})$, and $11kDa({\delta})$; which are very similar to those, $65({\alpha})$, $32({\beta})$, $25({\gamma})$, and $11kDa({\delta})$ of Acinetobacter enzyme. The ${\delta}-subunit$ of the active form of the enzymes was acetylated. The acetyl group may form a thioester bond with the thiol group of the prosthetic group covalently linked to the enzyme. It suggests that such molecular organization is common in all malonate decarboxylases.

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Effect of Linker for Immobilization of Glutathione on BSA-Assembled Controlled Pore Glass Beads

  • Chen, Li-Hua;Choi, Young-Seo;Park, Jung-Won;Kwon, Joseph;Wang, Rong-Shun;Lee, Tae-Hoon;Ryu, Sung-Ho;Park, Joon-Won
    • Bulletin of the Korean Chemical Society
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    • v.25 no.9
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    • pp.1366-1370
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    • 2004
  • Controlled pore glass bead was modified with bovine serum albumin (BSA), and glutathione (GSH) was immobilized through three kinds of linkers on top of BSA. Bis(3-sulfo-N-hydroxysuccinimide suberate) sodium salt $(BS^3)$, N-hydroxysuccinimide 3-(2-pyridyldithio)propionate (SPDP), or N-hydroxysuccinimide 4-maleimidobutyrate (GMBS) was introduced into the BSA-bound matrix. Subsequently, GSH was immobilized by addition of thiol side chain into the maleimido moiety, replacing a disulfide group, or formation of an amide group upon releasing 3-sulfo-N-hydroxysuccimide group. It was observed that conjugation methodology played a critical role for activity of the immobilized GSH. SDS-PAGE chromatogram showed that the matrix of glutathione immobilized on BSA through GMBS manifested high selectivity towards glutathione-S-transferase (GST) in cell lysate.

Introduction of Chromophores on the Activated Surface of Poly(2-trialkylstannylthioethyl acrylate) Films (Poly(2-trialkylstannylthioethyl acrylate) 필름의 표면 활성화를 통한 발색단 도입)

  • Yun, Jong Chul;Do, Jung Yun
    • Polymer(Korea)
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    • v.36 no.6
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    • pp.795-802
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    • 2012
  • Surface modification of a hydrophobic acrylic polymer film has been performed through simple chemical treatment to give a reactive surface. 2-Triphenylstannylthioethyl acrylate was polymerized under UV-illumination with various contents of a comonomer. When the polymer film was treated with fluoride ion, thiol functional group (SH) was generated on the film surface, which was observed through infrared absorption spectroscopy. The surface was functionalized by thiol addition reaction to acrylic chromophores. The SH content on the surface was controlled with a comonomer, tris(hydroxymethyl)ethane triacrylate, and examined with UV-Vis absorbance of the chromophore attached film. Similarly, a polymer film from 2-tributylstannylthioethyl acrylate was prepared. Destannylation from the triphenylstannyl and tributylstannyl surface completed after 30 and 5 min, respectively. The SH-exposed surface was modified with an isocyanate attached chromophore within 10 min, while acrylic chromophore required 24 h.