• BMB Reports
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• v.28 no.6
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• pp.527-532
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• 1995

Human taurine transporter has 12 transmembrane domains and its molecular weight is 69.6 kDa. The long cytoplasmic carboxy and amino termini might function as regulatory attachment sites for other proteins. Six potential protein kinase C phosphorylation sites have been reported in human taurine transporter. In this report, we studied the effects of phorbol 12-myristate 13-acetate (PMA) and glucocorticoid hormone on taurine transportation in the RAW 264.7, mouse macrophage cell line. When the cells were incubated with $[^{3}H]taurine$ in the presence or absence of $Na^+$ ion for 40 min at $37^{\circ}C$, the [$[^{3}H]taurine$ uptake rate was 780-times higher in the $Na^{+}-containing$ buffer than in the $Na^{+}-deficient$ buffer, indicating that this cell line expresses taurine transporter protein on the cell surface. THP1, a human promonocyte cell line, also showed a similar property. The $[^{3}H]taurine$ uptake rate was not influenced by the inflammatory inducing cytokines such as interleukin-1, gamma-interferon or interleukin-1+gamma-interferon, but was decreased by the PMA in the RAW 264.7 cell line. This suggests that activation of protein kinase C inhibits taurine transporter activity directly or indirectly. The inhibition of $[^{3}H]taurine$ uptake by PMA was time-dependent. Maximal inhibition occurred in one hr stimulation with PMA Increasing the treatment time beyond one h reduced the $[^{3}H]taurine$ uptake inhibition due to the depletion or inactivation of protein kinase C. The cell line also showed concentration-dependent $[^{3}H]taurine$ uptake under PMA stimulation. The phorbol-ester caused 23% inhibition at the concentration of 1 ${\mu}m$ PMA. The inhibition was significant even at a concentration as low as 10 nM PMA The reduced $[^{3}H]taurine$ uptake could be recovered by treatment with glucocorticosteroid hormone. Dexamethasone led to recover of the reduced taurine uptake induced by phorbol-ester, recovering maximally after one hr. This may suggest that macrophage cells require higher taurine concentration in a stressed state, for the secretion of glucocorticoid hormone is increased by hypothalamo-pituitary-adrenocortical (HPA) axis activation in the blood stream.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3061-3070
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• 2012

Novel 2-hexylthieno[3,2-b]thiophene-containing conjugated molecules have been synthesized via a reduction reaction using tin chloride in an acidic medium. They exhibited good solubility in common organic solvents and good self-film and crystal-forming properties. The single-crystalline objects were fabricated by a solvent slow diffusion process and then were employed for fabricating field-effect transistors (FETs) along with thinfilm transistors (TFTs). TFTs made of 5 and 6 exhibited carrier mobility as high as 0.10-0.15 $cm^2V^{-1}s^{-1}$. The single-crystal-based FET made of 6 showed 0.70 $cm^2V^{-1}s^{-1}$ which was relatively higher than that of the 5-based FET (${\mu}=0.23cm^2V^{-1}s^{-1}$). In addition, we fabricated organic photovoltaic (OPV) cells with new 2-hexylthieno [3,2-b]thiophene-containing conjugated molecules and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester ($PC_{61}BM$) without thermal annealing. The ternary system for a bulk heterojunction (BHJ) OPV cell was elaborated using $PC_{61}BM$ and two p-type conjugated molecules such as 5 and 7 for modulating the molecular energy levels. As a result, the OPV cell containing 5, 7, and $PC_{61}BM$ had improved results with an open-circuit voltage of 0.90 V, a short-circuit current density of 2.83 $mA/cm^2$, and a fill factor of 0.31, offering an overall power conversion efficiency (PCE) of 0.78%, which was larger than those of the devices made of only molecule 5 (${\eta}$~0.67%) or 7 (${\eta}$~0.46%) with $PC_{61}BM$ under identical weight compositions.

• Journal of the Korean Wood Science and Technology
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• v.51 no.3
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• pp.157-172
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• 2023

Azadirachta excelsa, is a plant belonging to the same genus as Indian neem (Azadirachta indica), and its use as a pesticide is reported by few studies. Despite being a different species, it is expected to have the same biopesticide potential as A. indica. Therefore, this study aims to investigate the anti-termite activity of n-hexane and methanol extracts of A. excelsa seed kernel at various concentrations against Coptotermes curvignathus. The methanol extract demonstrated greater termicidal activity than n-hexane at doses test of 2%, 4%, and 8%. It also showed 100% termite mortality on the third day of administering the 8% dose. According to the gas chromatography with mass spectrometry data, the putative main components of the n-hexane extract were hexadecanoic acid, ethyl ester (18.99%), 9,12-octadecadienoic acid (Z,Z)- (16.31%), and 9-octadecenal (16.23%). In contrast, the principal constituents of methanol extract were patchouli alcohol (28.1%), delta-guaiene (15.15%), and alpha-guaiene (11.93%). Furthermore, limonoids profiling of A. excelsa methanol extract was determined using Ultrahigh-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry. The number of limonoids identified tentatively was fifteen, such as 6-deacetylnimbin, nimbolidin C, nimbolide, 6-acetylnimbandiol, 6-deacetyl-nimbinene, salannol, 28-deoxonimbolide, gedunin, nimbandiol, epoxyazadiradione, azadirone, 2',3'-dihydrosalannin, marrangin, nimbocinol, and azadirachtin. They were the same as those reported in the seed and leaves of A. indica, but its largest component in A. excelsa was 6-deacetylnimbin. As a result, the presence of these compounds may be responsible for the anti-termite activity of A. excelsa seed kernel extract. Additionally, column chromatography of methanol extract yielded 6-deacetylnimbin, which was found to be antifeedant and termiticide against C. curvignathus.

• Biomolecules & Therapeutics
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• v.32 no.1
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• pp.84-93
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• 2024

Rosmarinic acid (RA) is a phenolic ester that protects human keratinocytes against oxidative damage induced by ultraviolet B (UVB) exposure, however, the mechanisms underlying its effects remain unclear. This study aimed to elucidate the cell signaling mechanisms that regulate the antioxidant activity of RA and confirm its cyto-protective role. To explore the signaling mechanisms, we used the human keratinocyte cell line HaCaT and SKH1 hairless mouse skin. RA enhanced glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS) expression in HaCaT cells in a dose- and time-dependent manner. Moreover, RA induced nuclear factor erythroid-2-related factor 2 (NRF2) nuclear translocation and activated the signaling kinases protein kinase B (AKT) and extracellular signal-regulated kinase (ERK). Treatment with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, the ERK inhibitor U0126, and small interfering RNA (siRNA) gene silencing suppressed RA-enhanced GCLC, GSS, and NRF2 expression, respectively. Cell viability tests showed that RA significantly prevented UVB-induced cell viability decrease, whereas the glutathione (GSH) inhibitors buthionine sulfoximine, LY294002, and U0126 significantly reduced this effect. Moreover, RA protected against DNA damage and protein carbonylation, lipid peroxidation, and apoptosis caused by UVB-induced oxidative stress in a concentration-dependent manner in SKH1 hairless mouse skin tissues. These results suggest that RA protects against UVB-induced oxidative damage by activating AKT and ERK signaling to regulate NRF2 signaling and enhance GSH biosynthesis. Thus, RA treatment may be a promising approach to protect the skin from UVB-induced oxidative damage.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.326-329
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• 2015

This study is to develop the double capsulation technology in order to increase the conservativeness and stability of unstable materials such as vitamins, polyphenols, natural active ingredients. And also, best way of triple matrix capsulation using natural polymers were detail described. As the first capsulation with w/o/w (water-in-oil-in-water) emulsifying system, our study group was especially made to soft and moisture cream using 5wt% of sucrose ester emulsifier as first capsulation. Nutrient agents are squalane, camellia oil. Triple matrix capsulation was formed with the best stabilized bead type capsules when it blended of chitosan, algin, sodium-potassium alginate. The bead diameter size was about 2.0~4.5mm (mean diameter: 3.2mm). Activity of lactobacillus containing cream for depending on various pH variations showed that alkalinity ($pH=10.8{\pm}0.5$) condition was higher than acidity ($pH=4.2{\pm}0.2$) and neutrality ($pH=7.1{\pm}0.3$) conditions. After a month, it also was certified to the activity of lactobacillus in incubated at $37{\pm}1^{\circ}C$ in culture medium. As application of food industry, we developed the containing lactobacillus capsule and 7 colored kinds of double and triple matrix capsulation in yogurt cream and active ingredients. As for above mentioned those results, one of tool to stabilize the living lactobacillus, doubled matrix capsulation greatly be expected to contribute to food industry. Furthermore, it can be expected to apply the drug delivery system (DDS) to active ingredients of stabilizing technologies at drug, pharmaceutical division and cosmetic industry, etc.

• Korean Journal of Pharmacognosy
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• v.37 no.2 s.145
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• pp.67-73
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• 2006

The butanol extracts of Agrimonia pilosa (BAP) induced dose-dependent vascular relaxation of phenylephrine-precontracted aorta, which was abolished by removal of functional endothelium. Pretreatment of the endothelium-intact aortic tissues with $N^G$-nitro-L-arginine methyl ester (L-NAME) and 1H-[1,2,4]-oxadiazole-[$4,3-{\alpha}$]-quinoxalin-1-one(ODQ) inhibited the relaxation induced by BAP. BAP-induced vascular relaxation was also markedly attenuated by addition of verapamiI, while the relaxant effect of BAP was not blocked by indomethacine, glibenclamide, tetraethylammonium (TEA), atropine, or propranolo. In addition, incubation of endothelium-intact aortic rings with BAP increased the vascular production of cGMP. These results suggest that BAP relaxes vascular smooth muscle via endothelium-dependent nitric oxide/cGMP signaling pathway, which may be causally related with L-type $Ca^{2+}$ channels.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.656-662
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• 1998

To make a distinction between the influence of the dielectric constant and of methanol concentration on trypsin-catalyzed hydrolysis and methanolysis at $0^{\circ}C$, a model reaction of $N^u$-benzyloxycarbonyl-L-lysine p-nitrophenyl ester with water-methanol mixtures was chosen and a kinetic study done. The $k_{cat}$ values increased with methanol concentration, in a linear manner whereas $K_{M}$ values increased in a log-linear fashion. However, the $k_{cat},$_{M}$ ratio increased at lower methanol concentrations than 30% and then began to decrease at higher concentrations. The decrease in $k_{catK_M}$observed at higher than 30% methanol concentrations is attributed to the hydrophobic partitioning effect on substrate binding. On the other hand, the increase in $k_{catK_M}$ in the 0~30% methanol concentration range seems to be due to the effect of nucleophilic cosolvent on $k_{cat}$ and of the dielectric constant on $k_m$. This explanation was verified by measuring the effect of varying the dielectric constant of the medium on kinetic constants with isopropyl alcohol chemically unrelated to the enzyme reaction as the methanol concentration is maintained at a constant level. Therefore, we conclude that the effect of increasing the methanol concentration in the model reaction on the kinetic parameters $k_{cat \;and\;{K_M}}$ is caused by changes in both the nucleophilicity and the dielectric constant of the medium. Based on product analysis, the increase in $k_4, k_3$by decreasing the temperature can be accounted for by the suppression of hydrolytic reactions. This observation indicates that the nucleophile is favored by low temperatures. There was no loss of trypsin activity over a 10 h period in 60% methanol concentration at $pH^＊\; 5.5,\; 0^{\circ}C$.EX>.

• BMB Reports
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• v.44 no.7
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• pp.468-472
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• 2011

Toll-like receptors (TLRs) are pattern recognition receptors that recognize molecular structures derived from microbes and initiate innate immunity. TLRs have two downstream signaling pathways, the MyD88- and TRIF-dependent pathways. Dysregulated activation of TLRs is closely linked to increased risk of many chronic diseases. Previously, we synthesized fumaryl pyrrolidinone, (E)-isopropyl 4-oxo-4-(2-oxopyrrolidin-1-yl)-2-butenoate (IPOP), which contains a fumaric acid isopropyl ester and pyrrolidinone, and demonstrated that it inhibits the activation of nuclear factor kappa B by inhibiting the MyD88-dependent pathway of TLRs. However, the effect of IPOP on the TRIF-dependent pathway remains unknown. Here, we report the effect of IPOP on signal transduction via the TRIF-dependent pathway of TLRs. IPOP inhibited lipopolysaccharide- or polyinosinic-polycytidylic acidinduced interferon regulatory factor 3 activation, as well as interferon-inducible genes such as interferon inducible protein-10. These results suggest that IPOP can modulate the TRIF-dependent signaling pathway of TLRs, leading to decreased inflammatory gene expression.

• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.224-231
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• 2006

agents used for enhancing mechanical properties of porous natural scaffolds, reduces biocompatability of the scaffolds, due to their inherent cytotoxicity. In this study, scaffolds which was composed of chitosan, alginate and gelatin were cross-linked by using heat treatment instead of cross-linking agent and mechanical properties of the cross-linked scaffold were investigated. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed that cross-linking of heat-treated scaffold was formed via amide or ester linkage between the polymer chains. The heat-treated scaffold had interconnected pores with mean diameter of 100~200 m and showed more than two fold increase of water uptake in comparison with chemically cross-linked scaffold. Tensile strength of the heat-treated scaffold increased up to 130% compared to non cross-linked scaffold and average maximum elongation was 11.3%. The porous cross-linked scaffold with the improved mechanical property may be suitable as a biocompatable scaffold for tissue engineering.

• Polymer(Korea)
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• v.33 no.4
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• pp.307-312
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• 2009

The fabrication of PHBV nanofibers containing various plant polyphenols by electrospinning has been examined. It has been found that the average diameters of fibers increased by the adding of polyphenols. The resulting fibers exhibited a uniform diameter ranging from 340 to 450 nm. As the concentration of polyphenols increased, the diameter of fibers increased due to the hydrogen bonding interaction between the ester groups of PHBV and hydroxyl groups of polyphenols. The interaction between PHBV and polyphenols, which forms a complex together in solution, was verifed by UV measurement. ATR-FTIR analysis confirmed the existence of the hydrogen bonding interaction. The semicrystalline structure of the PHBV nanofiber was observed from XRD pattern. The crystallinity of PHBV nanofibers was increased by the adding of polyphenols. PHBV nanofibers containing polyphenols showed superior antimicrobial activities.