• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2303-2308
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• 2009

A thiocyanate poly(vinyl chloride) (PVC) membrane electrode based on [1,2-bis(diphenylphosphino)ethane]dihalopalladium( II), [(dppe)$PdX_2$, X = Cl ($L^1$), X = I ($L^2$)] as active sensor has been developed. The diiodopalladium complex, [(dppe)$PdI_2](L^2$) displays an anti-Hofmeister selectivity sequence: $SCN^-\;>\;I^-\;>\;{ClO_4}^-\;>\;Sal^-\;>\;Br^-\;>\;{NO_2}^-\;>\;{HPO_4}^-\;>\;AcO^-\;>\;{NO_3}^-\;>\;{H_2PO_4}^-\;>\;{CO_3}^{2-}$. The electrode exhibits a Nernstian response (-59.8 mV/decade) over a wide linear concentration range of thiocyanate ($(1.0\;{\times}\;10^{-1}\;to\;5.0\;{\times}\;10^{-6}$ M), low detection limit ($(1.1\;{\times}\;10^{-6}$ M), fast response $(t_{90%}$ = 24 s), and applicability over a wide pH range (3.5∼11). Addition of anionic sites, potassium tetrakis[p-chlorophenyl] borate (KTpClPB) is shown to improve potentiometric anion selectivity, suggesting that the palladium complex may operate as a partially charged carrier-type ionophore within the polymer membrane phase. The reaction mechanism is discussed with respect to UV-Vis and IR spectroscopy. Application of the electrode to the potentiometric titration of thiocyanate ion with silver nitrate is reported.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.417-421
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• 2008

The efficient synthesis of four mesitylene-based receptors 1-4 and their potentiometric response characteristics to alkali metal, alkaline earth metal, and transition metal ions, under various pH conditions are outlined. Receptor 1-based electrode exhibited more sensitive response to Ag+ ion (49 mV/decade of range from 10-6 to 10-2 M) than the 2-based electrode (47 mV/decade of range from 3 ´ 10-5 to 10-2 M), while the 3- and 4-based ones revealed sub-Nernstian below 40 mV/pAg+. All electrodes showed substantial responses to Ag+ ion under acidic condition, but there was almost nil-response to other transition metal ions (Fe2+, Co2+, Zn2+, Ni2+, Pb2+, Cd2+, Cu2+ and Hg2+). The association constant of receptor 1 toward Ag+ ion, measured by 1H NMR titration, showed the largest value (200 M-1) among the tested receptors. The results were interpreted with semi empirically-modeled structures.

• The Journal of Korean Medicine
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• v.26 no.1 s.61
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• pp.37-45
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• 2005

In the present study, we examined the effect of crude methanolic extract (CME) from Euonymus alatus (Thunb.) Sieb on arachidonic acid (AA) cascade in SKBR3 human breast cancer cell line. CME had a potent inhibitory activity of prostaglandin E2 (PGE2) release induced by A23187, a $Ca^{2+}$ ionophore. The inhibition was concentration-dependent, with the 50 value of about 5 M. CME had no inhibitory effect on A23187-induced phosphorylation of p42/p44 extracellular signal regulated kinase/mitogen-activated protein kinase or on the liberation of [14C]-AA from the cells labeled with [14C]-AA. However, CME concentration-dependently inhibited the conversion of AA to $PGE_2$ in microsomal preparations, showing its possible inhibition of cyclooxygenase (COX). In enzyme assay in vitro, CME inhibited the activities of both constitutive COX (COX­I) and inducible COX (COX-2) in a concentration-dependent manner, with the 50 values of about 0.8 and 2M, respectively. Lineweaver-Burk plot analysis indicated that CME competitively inhibited the activities of both COX-l and -2. This study is a first demonstration that CME directly inhibits COX activity.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.30-30
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• 2003

Without a definitive resolution of stoichiometry of cardiac Na$^{+}$-Ca$^{2+}$exchange (NCX), we cannot proceed to any quantitative analysis of exchange function as well as cardiac excitation-contraction coupling. The stoichiometry of cardiac NCX, however, is presently in doubt because reversal potentials determined by various groups range between those expected for a 3-to-1 and a 4-to-1 flux coupling. For a new perspective on this problem, we have used ion-selective microelectrodes to quantify directly exchanger-mediated fluxes of $Ca^{2+}$and Na$^{+}$in giant membrane patches. $Ca^{2+}$- and Na$^{+}$-selective microelectrodes, fabricated from quartz capillaries, are placed inside of the patch pipettes to detect extracellular ion transients associated with exchange activity. Ion changes are monitored at various distances from the membrane, and the absolute ion fluxes through NCX are determined via simulations of ion diffusion and compared with standard ion fluxes (Ca$^{2+}$ fluxes mediated by $Ca^{2+}$ ionophore, and Na$^{+}$ fluxes through gramicidin channels and Na$^{+}$/K$^{+}$pumps). Both guinea pig myocytes and NCX1-expressing BHK cells were employed, and for both systems the calculated stoichiometries for inward and outward exchange currents range between 3.2- and 3.4-to-1. The coupling ratios do not change significantly when currents are varied by changing cytoplasmic [Ca$^{2+}$] or by adding cytoplasmic Na$^{+}$. The exchanger reversal potentials, measured in both systems under several ionic conditions, range from 3.1- to 3.3-to-1. Taken together, a clear discrepancy from a NCX stoichiometry of 3-to-1 was obtained. Further definitive experiments are required to acquire a fixed number, and the present working hypothesis is that NCX current has an extra current via ‘conduction mode’.ent via ‘conduction mode’.

• Advances in Traditional Medicine
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• v.10 no.3
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• pp.173-183
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• 2010

Perilla frutescens var. acuta Kudo (PF) is a traditional Korean medicinal herb for allergic reaction regulation. In the present study, we investigated the effect of 30% ethanol extract powder of PF (EPPF) and rosmarinic acid (RA), the active compound of EPPF on various allergic reactions using in vivo and in vitro models. EPPF and RA significantly inhibited compound 48/48-induced systemic anaphylactic reaction and histamine release (P < 0.05). In addition, EPPF and RA significantly inhibited passive cutaneous anaphylaxis (PCA) in a dose-dependent manner (P < 0.05). These effects were stronger than those of disodium cromoglycate, the reference drug tested. EPPF and RA also significantly inhibited production of inflammatory cytokines, tumor necrosis factor-a interleukin (IL)-6, and vascular endothelial growth factor on the PCA reaction and phorbol 12-myristate 13-acetate and calcium ionophore A23187-stimulated human mast cell line, HMC-1 cells (P < 0.05). Moreover, EPPF and RA showed an inhibitory effect on lipopolysaccharide (LPS)-induced IL-4 production from whole spleen cells. Finally, EPPF and RA significantly decreased IL-4-dependent IgE production by LPS-stimulated whole spleen cells (P < 0.05). In conclusion, these results indicate that EPPF has potent anti-allergic activities.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1601-1608
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• 2010

A scandium(III) porphyrin-based fluoride-selective potentiometric sensor and its application in the analysis of hydrofluoric acid is described. Scandium(III) octaethylporphyrin, an ionophore recently developed for the optical fluoride sensor, was employed as a host molecule for the selective binding with fluoride in the plasticized PVC membrane. Nernstian response for $F^-$ between $10^{-4.6}$ to $10^{-1}$ M was observed at a glycine-phosphate buffer (pH 3.0). The selectivity pattern was observed as $F^-$, salicylate $\gg$ $SCN^-$ > $Cl^-$, $Br^-$, $NO_3{^-}$, $ClO_4{^-}$, which is consistent with the binding constant data measured in the plasticized PVC membrane based on a sandwich membrane method. This highly selective and reversible fluoride-sensitive electrode was employed for the analysis of hydrofluoric acid (HF). A disposable differential-type HF sensor was fabricated on the screen-printed electrode and demonstrated its ability to detect the neutral HF in the acidic solution.

• The Korea Journal of Herbology
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• v.35 no.5
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• pp.13-21
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• 2020

Objective : The genus Glycyrrhiza has been used in food and traditional herbal medicine. Many experimental studies reported that Glycyrrhiza species possess several pharmacological properties. Glycyrrhiza new varieties WONGAM and SINWONGAM have been developed by Korea Rural Development Administration doing research for registration on Ministry of Food and Drug Safety. During the evaluations about pharmacological effect of Glycyrrhiza new varieties WONGAM and SINWONGAM, we focused the anti-allergic effect in this study. Methods : We investigated the anti-allergic effect of WONGAM and SINWONGAM compared with Glycyrrhiza uralensis Fischer and G. glabra L. using anti-dinitrophenyl-immunoglobulin E (IgE)/human serum albumin-stimulated RBL-2H3 cells, phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated HMC-1 cells and compound 48/80-induced anaphylaxis mice model. We analyzed the effect on the expression of various cytokines, and IgE from mast cells and the underlying molecular mechanisms of WONGAM and SINWONGAM in presented models. Results : WONGAM and SINWONGAM showed the inhibitory effect on the histamine release from rat peritoneal mast cells or human mast cells without cytotoxicity. WONGAM and SINWONGAM blocked anaphylactic shock and decreased the IgE production. Furthermore, WONGAM and SINWONGAM inhibited the productions of TNF-α and IL-6 in compound 48/80-induced anaphylaxis mice model. Conclusion : These results indicated that WONGAM and SINWONGAM would have protect effect on allergic responses through the inhibition of allergic mediators and pro-inflammatory cytokines. This study may facilitate the development on Glycyrrhiza new varieties for allergy.

• Journal of Korean Medicine Rehabilitation
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• v.15 no.2
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• pp.31-43
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• 2005

목적 : 방풍은 임상적으로 관절염을 포함한 다양한 염증성 질환 치료제로 사용되어 왔다. 본 연구에서는 인간 비만세포를 이용하여 세포 독성에 영향을 주지 않는 농도에서 방풍의 항염 효과 및 그 기전을 검토했다. 방법 : 인간의 HMC-1세포를 IMDM에서 페니실린, 스트렙토마이신, 모노티오글리세린을 첨가하여 배양하고 방품추출액을 투여하였다. 그 다음 MTT, CLISA, RT-PCR, 세포내 칼슘측정, 핵단백분석을 이용하여 TNF-${\alpha}$, IL-6, IL-8 각각의 형성과 mRNA발현, 세포내 칼슘 수준, NF-${\kappa}B$ 발현에 대한 방풍추출액의 반응을 측정하고 통계처리 하였다. 결과 : 방풍은 PMA와 calcium ionophore A23187로 활성화된 비민세포에서 세포내 칼슘 수준과 NF-${\kappa}B$, TNF-${\alpha}$와 IL-6의 발현을 억제시켰고 RT-PCR을 이용한 mRNA 발현에서 TNF-${\alpha}$와 IL-6의 발현을 억제하였다. 결론 : 방풍은 비만세포내 칼슘 수준 및 NF-${\kappa}B$의 활성을 억제하고 염증성 세포 활성 물질인 TNF-${\alpha}$와 IL-6의 분비도 억제하여 항염효과를 나타냄을 암시하고 있다.

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.840-848
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• 1992

An ionizable macrocyclic ligand, diaza-18-crown-6-diisopropionic acid(K22DAP) has been synthesized. Protonation constants of this compound and stability constants with some lanthanides were determined by potentiometric titration method. The protonation constants are log$K_1$ = 9.05, log$K_2$ = 8.37, log$K_3$ = 1.88 and log$K_4$ = 0.99. The logarithmic values of stability constants with La(III), Nd(III), Gd(III) and Lu(III) are 11.14, 11.43, 11.74 and 10.88 respectively. Extraction behavior of Ln(III) ion was investigated using TTA(thenoyltrifluoroacetone) as extractant in the presence of K22DAP as macrocyclic ionophore. It was observed that Ln(K22DAP)TTA is the dominating species in aqueous complexes of La(III) and Nd(III).

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.59-62
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• 2004

The ammonium ion-selective electrodes ($NH^+_4$-ISEs) based on the tetrahydrofuran(THF)-containing-16-crown-4 derivatives,1,4,6,9,11,14,16,19-tetraoxocycloeicosane ($L^1$) and 5,10,15,20,-tetramethyl-1,4,6,9,11,14,16,19-tetraoxocycloeicosane ($L^2$), were prepared and the electrode characteristics were tested. The conditioned $NH_4^+$-ISEs (E1) based on $L^1$ with TEHP as a plasticising solvent mediator gave best results with near-Nernstian slope of 53.9 mV/decade of activity, detection limit of $10^{-4.9}$ M, and enhanced selectivity coefficients for the $NH^+_4$ ion with respect to an interfering $K^+$ ion (log $K^{pot}_{NH_4^+,K^+}$ = -1.84). This result was compared to other ammonium ionophores reported previously, for example, that of nonactin (log $K^{pot}_{NH_4^+,K^+}$ = -0.92). The proposed electrode showed no significant potential changes in the range of 3.0 < pH < 9.0.