• Proceedings of the PSK Conference
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• 2001.04a
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• pp.172.1-172.1
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• 2001

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.141.2-142
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• 2003

beta-Amyloid (A$\beta$) peptide is the major component of senile plaques and considered to have a causal role in the development and progression of Alzheimer's disease. There has been compelling evidence supporting that $A\beta$-induced cytotoxicity is mediated through oxidative and/or nitrosative stress. Recently, considerable attention has been focused on dietary manipulation of oxidative and/or nitrosative damage. L-Egrothioneine (EGT) is a low-molecular weight naturally occurring thiol compound of dietary origin which exists in milimolar concentrations in the brain, liver, kindney, erythrocytes, ocular tissues and in seminal fluids of mammals. (omitted)

• 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.

• Journal of the Korean Chemical Society
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• v.47 no.5
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• pp.439-446
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• 2003

Surface-enhanced Raman(SER) spectroscopy was utilized to investigate the adorption orientation of the 4-biphenylcarboxylic acid(BPCA) derivatives, such as 4'-cyano-BPCA(c-BPCA), 4'-mercapto-BPCA(m-BPCA), and 4'-amino-BPCA(a-BPCA), which were adsorbed on Au and Ag colloid monolayers. For the systematic approach, information regarding the adsorption behavior of benzoic acid, biphenyl, and BPCA was applied to the target molecules. From the spectral behaviors of benzene ring, C-H stretching, carboxylate anion, and the other finger printing vibrational modes, it was concluded that only the m-BPCA was adsorbed tilt with thiol group being adsorbed on Au surface, whereas the other molecules were adsorbed flat on both Au and Ag surfaces.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.603-608
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• 2004

Traditional Jeju tofu with a hard texture was manufactured by traditional method with a compounded coagulant. The processing condition for industrial production was optimized by determining soaking of soybean, extraction and heat treatment of soymilk as well as concentration and composition of coagulant. Maximum yield of soymilk was obtained by grinding one part of soaked soybean with eight parts of water, and the soluble solid of soymilk was about 8$^{\circ}$Brix. The free thiol group in soymilk was maximally exposed by heating at 10$0^{\circ}C$ for 2 min. A vacuum cooker for heating soymilk was effective for the improvement of yield and texture properties of tofu. The hardness of traditional Jeju tofu was obtained by increasing pressing time and drying by a fan instead of soaking in cold water. Optimization of a traditional tofu production resulted in the increase of total yield and improvement of quality control. Texture of traditional Jeju tofu prepared in industrial production scale was analyzed by instrumental analysis and sensory evaluation. Traditional Jeju tofu showed higher score in the hardness, roasting taste and overall preference compared with a commercial tofu, showing significant difference in 5% significant level..

• Korean journal of food and cookery science
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• v.16 no.2
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• pp.128-134
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• 2000

Cysteine, a thiol group-containing reducing agent which is known to relax the strain and increase the viscosity of dough, was added to Korean and imported wheat flour noodles to investigate the effect on the properties of raw, dried, and cooked noodles and to determine the optimum cooking time and amount to improve the color of noodles. Addition of cysteine up to 1% of flour (8.25 mmole/100 g flour) was not effective in increasing the brightness of raw and dried noodles and in changing the water activity of dried noodle. However, cysteine improved the brightness of cooked noodle made of both Korean and imported wheat flours. Also, there were notable differences in cooking and sensory properties of cysteine-added cooked noodles such as less firm and stickier texture due to the extraction of organic compounds into broth. When the noodles were cooked for their optimum cooking time, no difference was noticed in the texture and overall preference regardless of the addition of cysteine. Overall, the addition of 1 % cysteine increased the brightness of cooked noodles and reduced the cooking time.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.601-612
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• 2020

The study assessed the stability for fresh beef patties with the inclusion of clove extract (CE) as a natural antioxidant in comparison to butylated hydroxytoluene (BHT) and ascorbic acid (AA) at frozen storage. Four different patties were made dependent on the added antioxidants: control (added no antioxidants), added with 0.02% BHT, 0.05% AA, and 0.1% CE. Inclusion of BHT, AA, and CE resulted in a significant reduction of thiobarbituric acid reactive substances (TBARS) and hue angle (h°) value and increase of redness (CIE a*) and chroma (C*) values (p<0.05). BHT, AA, and CE were observed effectively to retard lipid oxidation and increase color stability. BHT and AA revealed significantly (p<0.05) higher thiol content than the control and CE. However, the reduction percentage for thiol content in CE treated patties was lower than the control and AA-treated patties from first to last time of storage. Moreover, inclusion of AA and CE led to significantly (p<0.05) increased heme iron content when compared to BHT and the control. In conclusion, CE can replace the application of AA and BHT while improving lipid stability, heme iron content, and color stableness of fresh beef patties throughout frozen storage.

• Journal of Microbiology
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• v.38 no.3
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• pp.160-168
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• 2000

A-factor I a microbial hormone that can positively control cell differentiation leading to spore formation and secondary metabolite formation in Streptomyces griseus. to identify a protease that is deeply involved in the morphological and physiological differentiation of Streptomyces, the proteases produced by Streptomyces griseus IFO 13350 and its A-factor deficient mutant strain, Streptomyces griseus HH1, as well as Streptomyces griseus HH1 transformed with the afsA gene were sturdied. In general Streptomyces griseus showed a higher degree of cell growth and protease activity in proportion to its ability to produce a higher amount of A-factor. In particular, the specific activity of the trypsin of Streptomyces griseus IFO 13350 was greatly enhanced more than twice compared with that of Streptomyces griseus HH1 in the later stage of growth. The specific activity of the metalloprotease of Streptomyces griseus HH1 was greatly enhanced more than twice compared with that of Streptomyces griseus IFO 13350, and this observation was reversed in the presence of thiostreptione, However, Streptomyces griseus HH1 transformed with the afsA gene showed a significantly decreased level of trypsin and metalloprotease activity compared with that of the HH1 strain. There was no significant difference between Streptomyces griseus IFO 13350 and HH1 strain in their chymotrypsin and thiol protease activity, yet the level of leu-amionpeptidase activity was 2 times higher in Streptomyces griseus HH1 than in strain IFO 13350 . Streptomyces griseus HH1 harboring afsA showed a similar level of enzyme activity , however, all the three protease activities sharply increased and the thiol protease activity was critically increased at the end of the fermentation. When a serine protease inhibitor, pefabloc SC, and metalloprotease inhibitor, EDTA, were applied to strain IFO 13350 to examine the in vivo effects of the protease inhibitors on the morpholofical differentiation, the formation of aerial meycelium and spores was delayed by two or three days.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1153-1157
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• 2011

A kinetic study is reported for aminolysis of S-4-nitrophenyl X-substituted thiobenzoates 3a-g in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. Thiol esters 3a-g are 7.8-47.6 fold more reactive than the corresponding oxygen esters (i.e., 4-nitrophenyl X-substituted benzoates 1a-g). Such reactivity order appears to be in accordance with the expectation that 4-nitrothiophenoxide in 3a-g is a better nucleofuge than 4-nitrophenoxide in 1a-g since the former is 2.64 pKa units less basic than the latter. Hammett plot for the reactions of 3a-g exhibit poor correlation coefficients ($R^2$ = 0.977-0.986) with negative deviation by substrates possessing an electrondonating group (EDG), while the Yukawa-Tsuno plots result in excellent linear correlation ($R^2$ = 0.995-0.997) with ${\rho}$ = 0.93-1.23 and r = 0.57-0.67, indicating that the negative deviation shown by substrates possessing an EDG is caused by ground-state stabilization through resonance interactions but not due to a change in ratedetermining step upon changing the nonleaving-group substituent X. The ${\rho}$ value increases as the incoming amine becomes more basic and more reactive, indicating that the RSP is not operative in the current reactions.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.50-55
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• 2005

New fast proton-conducting organic-inorganic nanocomposite membranes were successfully fabricated using polymer matrix obtained through proper oxidation of thiol ligands in (3-Mercaptopropyl) trimethoxysilane (MPTS) and hydrolysis/condensation reaction of (3-glycidoxypropyl) trimethoxysilane (GPTS). The obtained nanocomposite membranes showed relatively hirh proton-conductivity over $10^{-2}S/cm$ at $ 25^{circ}C$. The proton conductivities of the fabricated composite membranes increased up to $3.6{\times}10^{-1}$ S/cm cm by increasing temperature and relative humidity to $70^{circ}C$ and 100 $100RH\%$. The high proton conductivity of the composites Is due to the proton conducting path through the GPTS-derived 'pseudo-polyethylene oxide 'network in which sulfonic acid ligands work as a proton donor.