• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.123-123
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• 1998

A number of uracil derivatives have been developed as anti-AIDS drugs having a mechanism of inhibiting cellular reverse transcriptase. A simple and rapid assay technique for recently synthesized KR-V analogues was developed using a high-performance liquid chromatography, and oral pharmacokinetics was examined for assessing their oral bioavailabilites. Plasma samples were analyzed by reversed-phase HPLC using an ODS column with an ultraviolet detection system. All the analogues were eluted within 12 min and the LOQ was 15-30 ng/$m\ell$. The extraction recoveries were higher than 85%, except KR-V1039, 1068 and 1720 having ester group. This chromatic method was well applied to the kinetic studies for KR-V analogues. Among 16 analogues tested in the present work, the 6 compounds including KR-V1123, 1122, 1784, 1783, 1736 and 1700 were found to be bioavailable for oral administration to rats.

• KSBB Journal
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• v.24 no.3
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• pp.253-258
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• 2009

In this study, the optimization of fabrication conditions was accomplished to make immuno-strip biosensor by the combination of enzyme linked immunosorbent assay (ELISA) and immuno-chromatographic strip techniques for the detection of Escherichia coli O157 : H7. Optimal fabrication conditions of capture antibody concentration, detection antibody concentration, and additive composition of running buffer solution were determined. Optimal concentration was determined as 1.0 mg/mL for both of capture antibody and detection antibody. A composition of 0.5% Tween20 and 3% BSA were selected as optimal additive for buffer solution to prevent non-specific binding.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.607-612
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• 1998

In the course of our search for anti-Herpes simplex virus type I (HSV 1) substances from natural sources, we screened crude drugs for their antiviral activity using SRB assay. T he methanol extract from herb of Brassica rapa (Cruciferae) was found to inhibit HSV-1. Though bioassay-directed fractionation of the extract, anti-HSV-1 agent was isolated by chromatographic separation using Amberlite XAD-4 and Sephadex LH-20. The structure of compound I was elucidated by spectral means including $^1H-^1H$ COSY, HMQC and HMBC to be isorhamnetin 3-O-${\beta}$-D-glucopyranoside (compound I). Compound I was active against HSV-1 with the 50% effective concentration of O.42mg/ml and the 50% cytotoxicity of 5.0mg/ml.

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.619-623
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• 2004

Tissue factor (TF, tissue thromboplastin) is a membrane bound glycoprotein, which acceler-ates the blood clotting, activating both the intrinsic and the extrinsic pathways to serve as a cofactor for activated factor VII (Vila). The TF-factor Vila complex (TF/VIIa) proteolytically activates factors IX and X, which leads to the generation of thrombin and fibrin clots. In order to isolate TF inhibitors, by means of a bioassay-directed chromatographic separation technique, from the leaves of Eriobotrya japonica Lindley (Rosaceae), a known sesquiterpene glycoside (2) and ferulic acid (3) were isolated as inhibitors that were evaluated using a single-clotting assay method for determining TF activity. Another sesquiterpene glycoside (1) was also isolated but was inactive in the assay system. Compound 3 was yielded by alkaline hydrolysis of compound 2. The structures of compounds 1, 2, and 3 were identified by means of spectral analysis as $3-O-{\alph}-L-rhamnopyranosyl-(1{\rightarrow}4)-a-L-rhamnopyranosyl-(1{\rightarrow}2)-[{\alph}-L-rhamnopyrano-syl-(1{\rightarrow}6)]-{\beta}-D-glucopyranosyl nerolidol$ (1), $3-O-{\alph}-L-rhamnopyranosyl-(1{\rightarrow}4)-{\alph}-L-rhamnopyr-anosyl-(1{\rightarrow}2)-[{\alph}-L-(4-trans-feruloyl)-rhamnopyranosyl-(1{\rightarrow}6)]-{\beta}-D-glucopyranosyl$ nerolidol (2) and ferulic acid (3), respectively. Compounds 2 and 3 inhibited 50% of the TF activity at con-centrations of 2 and $369{\;}\mu\textrm{m}/TF$ units, respectively.

• Bulletin of the Korean Chemical Society
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• v.22 no.7
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• pp.685-688
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• 2001

A gas chromatography/mass spectrometric assay method has been developed for the simultaneous determination of benzidine (BZ), N-acetyl benzidine (ABZ) and N,N-diacetyl benzidine (DABZ) in rat urine. BZ, ABZ and DABZ were extracted from urine at pH 8 with ethyl ether. Conjugated urinary metabolites were extracted at pH 8 after hydrolysis with 1 M HCl for 30 min at 100 $^{\circ}C.$ The dried extract was dissolved in 100 ${\mu}{\ell}$ of ethylacetate and then injected in gas chromatography-mass spectrometric (GC-MS) system without further purification or modification. BZ, ABZ and DABZ have good chromatographic properties and offer very sensitive response for the EI-MS (SIM) without any derivatization. The recoveries for BZ, ABZ and DABZ were about 98.0, 81.8 and 71.4%, respectively, at pH 8.0 and the concentration of 5.0 ng/mL. The coefficients of variation of BZ and ABZ were less than 9.5% from 0.1 to 100 ng/mL and that of DABZ was less than 13% in the same concentration range. The detection limits of the assay were 0.01 ng/mL for both BZ and ABZ, and 0.05 ng/mL for DABZ in urine or plasma 1.0 mL.

• The Korean Journal of Zoology
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• v.36 no.2
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• pp.238-244
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• 1993

We identified juvenile hormone binding protein (JHBP) from last instar larval hemollvnph of Hvphantria cunea using gel filtration and non-SDS PAGE. Two kinds of JHBP in hemollnnph were found at two peaks by gel filtration (Sephadex G-100) and also at Rm values of 0.13 and 0.57 by non-SDS PAGE. JHBP was partially purified using anion exchange chromatosraphv, preparative gel filteration, and preparative PAGE. Dextrin coated charcoal (DCC) binding assay was employed to monitor the location of JHBP in chromatographic profile during the purification process. Purity of JHBP was checked by silver staining of 1091 SDS-Polyacrvlamide.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.105-105
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• 2003

A rapid and reproducible high performance liquid chromatographic assay of prazosin in human plasma was developed. After addition of internal standard (IS, terazosin hydrochloride) and alkalization of the plasma, the drug and IS were extracted into t-butylmethylether. The organic phase was back-extracted into 0.05% phosphoric acid and 50 ${\mu}\ell$ of the acid solution was injected into a reverse-phase C18 column with a mobile phase consisting of water : acetonitrile : triethylamine = 75 : 25 : 0.1 (pH 5.0). The samples were detected utilizing a fluorescence detector. A

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.520-523
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• 1999

We have been screening anti-HIV integrase compounds from Korean medicinal plants by using an in vitro assay system which is mainly composed of recombinant human immunodeficency virus type 1 integrase and radiolabeled oligonucleotides. From the above screening, the aqueous methanolic extract of the roots of Agastache rugosa exhibited a significant activity. Bioactivity-guided chromatographic fractionation of the methanolic extract resulted in the isolation of rosmarinic acid. The structure of the compound was determined by spectroscopic data and by the comparison with the reported values. The $IC_{50}$ of the rosmarinic acid was approximately $10{\mu}g/ml$ against HIV integrase.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.458-461
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• 1994

A new high-performance liquid chromatographic method with column switching has been onto a Bondapak phenyl/corsil $(37-50{\;}{\mu}m)$ precolumn and polar plasma components were washed with 0.06 M borate burffer. After valve switching, the concentrated drug were eluted in the back-flush mode and separated on a ${\mu}-Bondapak$ C18 column with acetonitrilke-phosphate buffer as the mobile phae. The method showed excellent precision, accuracy and speed with detection limit of $0.01{\;}{\mug}/ml^{-1}$. Total analysis time per smaple was less than 20 min and the coefficients of variation for intra and inter-assay were less than 5.635. This method has been successfully applied to plasma smaples from eats after oral administration of omeprazole.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.806-808
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• 2004

A gas chromatography/mass spectrometric assay method has been developed for the simultaneous determination of icing inhibitors, ethylene glycol monomethyl ether and diethylene glycol monomethyl ether in ground water contaminated with JP-8. Ethylene glycol monobutyl ether and ethylene glycol monoethyl ether were used as the internal standard and surrogate, respectively. 100 mL of ground water was extracted twice with 20 mL of methylene chloride. The extract was concentrated to dryness, dissolved with 100 ${\mu}$L of methanol and analyzed by GC-MS (SIM). The use of an Innowax column gave the peaks good chromatographic properties, and the extraction of these compounds from samples gave recoveries of about 50% with small variations. The method detection limits of the target compounds were in a range of 0.5-0.8 ng/mL in ground water.