• Advances in Traditional Medicine
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• v.6 no.3
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• pp.179-185
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• 2006

We investigated the effects of chronic administration of different extracts of ginger rhizome [pet ether extract (PE); toluene fraction (TF) of pet ether extract] on anxiety models: the elevated T-maze (ETM) (for inhibitory avoidance and escape measurements) and the open field test. Ondansetron (1 mg/kg), FE (10, 30 &100 mg/kg) and TF (10 & 30 mg/kg) were administered orally for 15 days. On the $14^{th}$ day mice were previously exposed for 30 min to one of the open arms of the T-maze, 24 h before the test. On $15^{th}$ day mice had two exposures to the enclosed and open arm of the ETM followed by exposure to the open field apparatus. The number of line crossings in the apparatus was used to assess locomotor changes. Cumulative Concentration Response Curve of 5-HT was plotted using rat fundus which were pretreated in a similar way. Treatment with Ondansetron (1 mg/kg), PE (100 mg/kg), TF (10 mg/kg) and TF (30 mg/kg) significantly (P<0.05) impaired inhibitory avoidance performance but did not impair escape latency. Concentration response curve of 5-HT was shifted towards the right with suppression of maxima in rats treated with PE and TF. The results suggest that PE and TF of Ginger rhizome exerts anxiolytic like behaviour in a specific subset of defensive behaviour, particularly those related to generalized anxiety disorder.

• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.151-155
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• 2004

The self-assembled mololayers(SAMs)were prepared with cysteine(cys) and subsequently coupled with dopamine(dopa) containing quinone functionality on the gold modified electrodes. The SAMs annealed in ethanol for 6 hours gave a better shaped cyclic voltammogram which had a 0.28 V of formal potential and same redox potential in 0.1M phosphate buffer(pH=7.10). The electrodes were employed to determine concentration of HADH with the result that calibration curve exhibited an excellent correlation(${\geq}$ 0.993) for the concentrations ranging up to 5.0${\times}10^{-4}$ M.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1202-1206
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• 2004

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/ MS) method for the determination of lithospermic acid B (LSB) in rat serum was developed. LSB and internal standard, 7-hydroxy-3-phenyl-chromen-4-one (HPC) were extracted from rat serum with methyl-tert-butyl ether at acidic pH and analyzed on a Luna $C_8$ column with the mobile phase of acetonitrile-ammonium formate (10 mM, pH 6.5) (50:50, v/v). The analytes were detected using a negative electrospray ionization tandem mass spectrometry in the multiple- reaction-monitoring mode. The standard curve was linear $(r^2 = 0.997)$ over the concentration range of 10.0-500 ng/mL. The coefficient of variation and relative error for intra- and interassay at three QC levels were 1.1~6.2% and -10.3~-2.7%, respectively. The recovery of LSB from serum sample ranged from 73.2 to 79.5%, with that of HPC (internal standard) being 75.1 %. The lower limit of quantification for LSB was 10 ng/mL using 50 ${\mu}L$ of serum sample.

• Advances in Traditional Medicine
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• v.7 no.3
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• pp.261-273
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• 2007

We investigated the antihypertensive effect of Pet ether extract (PE) of ginger rhizome; its toluene fraction (TF) and Korean ginseng extract (KGE) in deoxycorticosterone acetate (DOCA) - salt induced and fructose induced hypertensive rats. In DOCA model, DOCA (25 mg/kg, once a week; s.c) was administered in uninephrectomised animals for 4 w. PE (50 mg/kg/day; p.o), TF (10 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) were evaluated for their antihypertensive effect. In the fructose model, drinking water was replaced with fructose (10%) for five weeks to induce hypertension. PE (50 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) were assessed for its antihypertensive effect in fructose model. After completion of the treatment schedule, vascular reactivity to various agonists like 5-HT, noradrenaline, adrenaline, phenylbiguanide and acetylcholine were recorded in rats of both the models. A cumulative dose response curve (CDRC) of 5-HT was carried out in isolated rat fundus strip of the fructose induced hypertensive rats. Chronic administration of PE (50 mg/kg/day; p.o), TF (10 mg/kg/day; p.o), and KGE (30 mg/kg/day; p.o) significantly reduced the blood pressure in DOCA salt whereas PE (50 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) reduced the blood pressure in fructose induced hypertensive rats. Treatment with PE (50 mg/kg/day; p.o) and KGE (30 mg/kg/day; p.o) in fructose model for five weeks shifted the CDRC towards the right on rat fundus. The mechanism of action may partly involve the serotonergic antagonistic property.

• Bulletin of the Korean Chemical Society
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• v.23 no.10
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• pp.1381-1391
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• 2002

The solvent sublation using ion pairs of metal-2-naphthoate(2-HNph) and tetrabutyl ammonium ($TBA^+$) ion has been studied for the concentration and determination of ultra trace Bi(III), In(III) and Tl(Ⅲ) ions in water samples. The partition coefficients ($K_p$) and the extraction percentages of 2-HNph and the ion pairs to methyl isobutyl ketone (MIBK) were obtained as basic data. After the ion pair $TBA^+$·M$(Nph)_4^-$ was formed in water samples, the analytes were concentrated by the solvent sublation and the elements were determined by GF-AAS. The pH of the sample solution, the amount of the ligand and counter ion added and stirring time were optimized for the efficient formation of the ion pair. The type and amount of optimum surfactant, bubbling time with nitrogen and the type of solvent were investigated for the solvent sublation as well. 10.0 mL of 0.1 M 2-HNph and 2.0 mL of 0.1 M $TBA^+$ were added to a 1.0 L sample solution at pH 5.0. After 2.0 mL of 0.2%(w/v) Triton X-100 was added, the ion pairs were extracted into 20.0 mL MIBK in a flotation cell by bubbling. The analytes were determined by a calibration curve method with measured absorbances in MIBK, and the recovery was 80-120%.

• Journal of the Korean Chemical Society
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• v.44 no.2
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• pp.109-114
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• 2000

In this study, the optimum analytical condition of Differential pulse Voltammetry for the polymeric Sodium Alginate was studied and its reduction funtional groups were confirmed using Cyclic Vol-tammetry and IR spectroscopy. Optimum conditions were as followed; mercury drop size : medium size, accumulation time : 60sec, accumulation potential : -0.20V vs Ag/AgCl, scan rate : 100mV/sec, supporting electrolyte : 0.10M $NaClO_4$(pH 6.8). After polymeric Sodium Alginate was hydrolized at $100^{\circ}C$ in acidic condition, the current peaks of oligomer were compared with current peak of polymeric Sodium Alginate. In this optimum condition, calibration curve of polymer Sodium Alginate showed good linearity from 0.50ppm to 4.0ppm where as oligomeric Sodium Alginate showed good linearity from 0.05ppm to 0.24ppm.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.689-695
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• 1998

Carbobenzoxy-alanyl-thiaarginine benzyl ester and carbobenzoxy-alanyl-thialysine benzyl ester were synthesized in solution. Kinetic studies were carried out using three different analytical methods, semi-classical method, progress curve analysis and competitive spectrophotometry. In competitive spectrophotometry, carbobenzoxy-valyl-glycyl-arginyl-p-nitroaniline was used as a detector. Kinetic constants such as $K_m$ and $V_{max}$ measured by competitive spectrophotometry are almost the same as those values measured by semi-classical method. Colorimetric Ellman's assays showed the thio-peptido mimetics to be a suitable substrates for trypsin. Kinetic studies with trypsin gave $K_m$ of 2.33 mM and $k_{cat}$ of $1.50{\times}10^5\;min^{-1}$ for carboxy-alanyl-thiaarginine benzyl ester and $K_m$ of $3.41{\times}10^{-3}\; Mm\; and\; k_{cat}\; of\; 520{\times}102\; min^{-1}$ for carbobenzoxy-alanyl-thialysine benzyl ester, respectively. Kinetic constants $(K_m=2.04{\times}10^{-2}\; mM, K_{cat}=4.42{\times}10^3 \;min^{-1})$ for natural substrate, carbobenzoxy-alanyl-lysine benzyl ester, were also evaluated by competitive spectrophotometry in order to compare the mode of binding on trypsin.

• Progress in Medical Physics
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• v.25 no.3
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• pp.157-166
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• 2014

ATP in quantity co-stored with neurotransmitters in the secretory vesicles of neurons, by being co-released with the neurotransmitters, takes an important role to modulate the stimulus-secretion response of neurotransmitters. Here, in this study, the modulatory effect of ATP was studied in $Ca^{2+}$ channels of cultured rat adrenal chromaffin cells to investigate the physiological role of ATP in neurons. The $Ca^{2+}$ channel current was recorded in a whole-cell patch clamp configuration, which was modulated by ATP. In 10 mM $Ba^{2+}$ bath solution, ATP treatment (0.1 mM) decreased the $Ba^{2+}$ current by an average of $36{\pm}6%$ (n=8), showing a dose-dependency within the range of $10^{-4}{\sim}10^{-1}mM$. The current was recovered by ATP washout, demonstrating its reversible pattern. This current blockade effect of ATP was disinhibited by a large prepulse up to +80 mV, since the $Ba^{2+}$ current increment was larger when treated with ATP ($37{\pm}5%$, n=11) compared to the control ($25{\pm}3%$, n=12, without ATP). The $Ba^{2+}$ current was recorded with $GTP{\gamma}S$, the non-hydrolyzable GTP analogue, to determine if the blocking effect of ATP was mediated by G-protein. The $Ba^{2+}$ current decreased down to 45% of control with $GTP{\gamma}S$. With a large prepulse (+80 mV), the current increment was $34{\pm}4%$ (n=19), which $25{\pm}3%$ (n=12) under control condition (without $GTP{\gamma}S$). The $Ba^{2+}$ current waveform was well fitted to a single-exponential curve for the control, while a double-exponential curve best fitted the current signal with ATP or $GTP{\gamma}S$. In other words, a slow activation component appeared with ATP or $GTP{\gamma}S$, which suggested that both ATP and $GTP{\gamma}S$ caused slower activation of $Ca^{2+}$ channels via the same mechanism. The results suggest that ATP may block the $Ca^{2+}$ channels by G-protein and this $Ca^{2+}$ channel blocking effect of ATP is important in autocrine (or paracrine) inhibition of adrenaline secretion in chromaffin cell.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.199-203
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• 2004

Fibrous arsenic (As) adsorbent was synthesized by loading zirconium (Zr) on fibrous phosphoric adsorbent that was directly synthesized by radiation-induced graft polymerization of 2-hydroxyethyl methacrylate phosphoric acid on polyethylene-coated polypropylene nonwoven fabric. Zirconium reacted with phosphoric acid grafted in the polyethylene layer. Zirconium density of the resulting adsorbent was 4.1 mmol/g. The breakthrough curve of As(V) adsorption was independent of the flow rate up to $1300\;h^{-1}$ in space velocity. The total capacity of As(V) was 2.0 mmol/g-adsorbent at pH of 2. The adsorbed Zr(IV) could be evaluated by 0.4 M sodium hydroxide solution because negligible Zr(IV) could be found in the eluted solution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.397-400
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• 1997

This paper presentes the characteristics of Si anisotropic etching and electrochemical etch-stop in aqueous TMAH/IPA/pyrazine solution. (100) Si etching rate of 0.747 $\mu\textrm{m}$/min which faster 86% than TMAH 25 wt.%/IPA 17 vol.% solution was obtained using best etching condition at TMAH 25 wt.%/IPA 17 vol.%/pyrazine 0.1 g and the etching rate of (100) Si was decreased with more additive quantity of pyrazine. I-V curve of p-type Si in TMAH/IPA/pyrazine was obtained. OCP(Open Circuit Potential) and PP(Passivation Potential) were -2 V and -0.9 V, respectively. Si diaphragms were obtained by electrochemical etch-stop in aqueous TMAH/IPA/pyrazine solution.