• Bulletin of the Korean Chemical Society
• /
• v.31 no.11
• /
• pp.3103-3108
• /
• 2010

Conducting polymers (CPs) are widely used as matrixes for the entrapment of enzymes in analytical chemistry and biosensing devices. However, enzyme-catalyzed polymerization of CPs is rarely used for immunosensing due to the difficulties involved in the quantitative analysis of colloidal CPs in solution phase. In this study, an enzyme-amplified electrocatalytic immunosensor employing a CP as a redox marker has been developed. A polyanionic polymer matrix, $\alpha$-amino-$\omega$-thiol terminated poly(acrylic acid), was employed for precipitation of CP. The acrylic acid group acts as a polyanionic template. The thiol terminus of the polymer was used to produce self-assembled monolayers (SAMs) on Au electrodes and the amine terminus was employed for immobilization of biomolecules. In an enzymeamplified sandwich type immunosensor, the polyaniline (PANI) produced enzymatically is attracted by the electrostatic force of the matrix polymer. The precipitated PANI was characterized by electrochemical methods.

• The Korean Journal of Zoology
• /
• v.25 no.3
• /
• pp.115-122
• /
• 1982

Plasma albumin was purified from the fresh bovine blood using a minor modification of the polyethyleneglycol and ethanol procedure. The resulting protein solution was tested for its purity by both electrophoretic and immunochemical methods and found to contain only the albumin molecules. Each of the four thiol reagents, maleate, iodoacetate, iodoacetamide and glutathione, was incubated with the purified plasma albumin. The electrophoresis on cellulose acetate of those complexes in various buffers with different component and pH demonstrated that the albumin-glutathione complex was separated into two zones in all buffers used except the barbital and sodium acetate buffers, that the complexes of albumin-iodoacetate and albumin-iosoacetamide also into two zones only in pH 4.8 citrate buffer and in pH 4.8 succinate buffer and that the new zone had more positive net charge compared to the native protein in any case. These results might suggest a possibility that the electrophoretic albumin fraction is composed of at least two molecular species with different conformation.

• Journal of the Korean Chemical Society
• /
• v.55 no.4
• /
• pp.656-661
• /
• 2011

5-(3,4,5-Triethoxyphenyl)-1,3,4-oxadiazole-2-thiol 6 on treatment with substituted 3-(bromomethyl)-2-chloroquinoline or 2-(p-tolyloxy)-3-(bromomethyl)quinoline 4a-j afforded the corresponding 3-((5-(3,4,5-triethoxyphenyl)-1,3,4-oxadiazol-2-ylthio)methyl)-2-chloroquinoline or 3-((5-(3,4,5-triethoxyphenyl)-1,3,4-oxadiazol-2-ylthio)methyl)-2-(p-tolyloxy)quinoline 7a-j, in the presence of $K_2CO_3$ and DMF under stirring at ambient temperature. All the synthesized compounds were further screened for their antibacterial activities. Some of our compounds showed excellent antibacterial activities against test organisms and reference standard.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.6
• /
• pp.953-958
• /
• 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.

• Archives of Pharmacal Research
• /
• v.28 no.4
• /
• pp.438-442
• /
• 2005

A series of 3-[1-(4-(2-methylpropyl) phenyl) ethyl]-1,2,4-triazole-5-thione (I) and its bicyclic condensed derivatives 6-benzylidenethiazolo[3,2-b]-1, 2,4-triazole-5(6H)-ones (IIa-IIf) were investigated for the prevention of ethanol-induced oxidative stress in liver and brain of mice. Administration of ethanol (0.1 mL/mice, p.o.) resulted in a drop of total thiol groups (T-SH) and non-protein thiol groups (NP-SH), and an increase in thiobarbituric acid reactive substances (TBARS) in both liver and brain tissue of mice (p<0.001). Among the compounds investigated (at a dose of 200 mg/kg, p.o.), I and IId ameliorated the peroxidative injury in these tissues effectively. Compounds IIa, IIc and IIe improved the peroxidative tissue injury only in brain. These findings suggest that certain condensed thiazolo-triazole compounds may contribute to the control of ethanol-induced oxidative stress in an organ selective manner.

• The Plant Pathology Journal
• /
• v.21 no.4
• /
• pp.355-360
• /
• 2005

Sulfur, an important component of plants, is regulated by a variety of stresses in sulfate assimilation and metabolism. Increase has been observed in the expression of O-acetylserine(thiol)lyase (OASTL) through two-dimensional electrophoresis with the shoot tips of Arabidopsis infected by beet severe curly top geminivirus (BSCTV). With the three- to six-fold increases in the transcript expression of OASTL, serine acetyltransferase (SAT) and $\gamma$-glutmylcysteine synthetase (GSH) were induced over the mock-inoculated organization in each organization through real-time RT-PCR analysis. The expression of those genes might affect the accumulation of anthocyanin in symptomatic tissues and the induction of abnormal callus-like structures formed by additional cell divisions as typical disease symptoms of BSCTV-infected Arabidopsis. This is the first report to describe the collaborative induction of OASTL, SAT, and GSH in virus-infected plants. The changed expressions of OASTL, SAT, and GSH in Arabidopsis infected with BSCTV raises new aspects regarding the biological function of symptomatic tissues related to sulfate metabolism.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.8
• /
• pp.700-706
• /
• 1996

We present the results of molecular dynamics simulations of monolayers of long-chain alkyl thiol [S(CH2)15CH3] molecules on an air-solid interface using the extended collapsed atom model for the chain-molecule and a gold surface for the solid surface. Several molecular dynamics simulations have been performed on monolayers with areas per molecule ranging from 18.30 to 32.10 Å2/molecule. It is found that there exist three possible transitions: a continuous transition characterized by a change in molecular configuration without change in lattice structure, a sudden transition characterized by the distinct lattice defects and perfect islands, and a third transition characterized by the appearance of a random, liquid-like state. The analysis of probability distributions of the segments shows that the structure of the chain-molecules at the air-solid interface is completely different from that at the air-water interface in the view of the degree of overlap of the probability distributions of the neighbor segments. The calculated diffusion coefficients of the chain-molecules on the monolayers seem to be not directly related to any one of the three transitions. However, the large diffusion of the molecules enhanced by the increment of the area per molecule may induce the second transition.

• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.4 no.2
• /
• pp.85-89
• /
• 2018

We demonstrate a detail protocol for the radiosynthesis of an $^{125}I$-labeled MSTP prosthetic group and its application to the efficient radiolabeling of human serum albumin (HSA). Radioiodination of the precursor (2) was carried out by using $[^{125}I]$NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified $^{125}I$-labeled MSTP ($[^{125}I]1$) was obtained with high radiochemical yield ($73{\pm}5%$, n = 3) and excellent radiochemical purity (>99%). Site-specific reaction between ($[^{125}I]1$) and HSA gave the $^{125}I$-labeled human serum albumin ($[^{125}I]3$) with more than 99% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly demonstrate that the present radiolabeling method will be useful for the efficient and convenient radiolabeling of thiol-bearing biomolecules.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.7
• /
• pp.1027-1035
• /
• 2019

Objective: The aim of this study was to investigate the effects of aged garlic powder (AGP) on physicochemical characteristics, texture profiles, and oxidative stability of ready-to-eat (RTE) pork patties. Methods: There were five treatment groups: a control; 1% fresh garlic powder (T1); 0.5%, 1%, and 2% AGP (T2, T3, and T4). Pork patties with vacuum packaging were roasted at $71^{\circ}C$ for core temperature, stored at $4^{\circ}C$ for 14 d, and then reheated for 1 min using a microwave. Results: The AGP groups showed a lower the level of lipid oxidation and higher thiol contents than the control and T1. The pH value of the control increased whereas that of aged garlic groups decreased after re-heating process. In addition, the redness significantly increased with increasing level of AGP whereas the redness of the control and T1 decreased after reheating process. T4 added patties improved textural and sensory properties compared to the control. Conclusion: The results of this study suggest that AGP addition to RTE pork patties can improve their sensory characteristics and oxidative stability.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.3
• /
• pp.366-371
• /
• 2011

This study was carried out to investigate the quality characteristics and antioxidant activities of the commercial black garlic (NHBG: Namhae black garlic, USBG: Uiseng black garlic, CNBG: Changnyung black garlic) and FABG (fermented and aged black garlic). The sugar contents of NHBG, USBG, CNBG, and FABG were 42.7, 42.7, 56.7 and $54.7^{\circ}Brix$, respectively, whereas the reducing sugar contents were 15.0, 16.0, 23.5 and 25.9%. The pH decreased with the processing of the fermented aged black garlic, whereas the acidity increased. In addition, the thiol content was the highest in fermented and aged black garlic (p<0.05). The antioxidant activities by DPPH and hydroxyl radical scavenging activity of fermented and aged black garlic were much higher than those of the other samples. Total phenol contents of NHBG, USBG, CNBG and FABG were 0.64 mg/mL, 0.60 mg/mL, 0.68 mg/mL and 0.72 mg/mL, respectively. ABTS radical scavenging activity of fermented and aged black garlic were much higher then those of the other samples. FRAP values of NHBG, USBG, CNBG, and FABG were 1.7 mg/mL, 1.4 mg/mL, 1.7 mg/mL and 1.9 mg/mL, respectively. Based on these results, it is suggested that the fermented and aged black garlic was appropriate for good qualities in terms of both physicochemical and antioxidative activities.