• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.206-206
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• 2002

The bioequivalence of two 4 mg triamcinolone tablets (Dong-Kwang $\textrm{Tramcinolone}^{(R)}$ vs. Wyeth Korea $\textrm{Ledercoat}^{(R)}$) was assesed in healthy male Korean volunteers after oral administration of 16 mh triamcinolone in a randomized crossover study. Blood samples were collected at specified time intervals, and plasma was analyzed for triamcinolone using a validated HPLC method. The pharmacokinetic parameters of $T_{max}$, $C_{max}$, $AUC_{0{\longrightarrow}last}$. $AUC_{0{\longrightarrow}imf}$, and $T_{1/2,\beta}$ were determined from plasma concentration-time profile of two formulations. The pharmacokinetic parameters were statistically compared to evaluate bioequivalence between two formulations, according to the United State or Korea Food and Drug Administration Guidelines. The analysis of variance did not show any signigicant difference between the two formulations and 90% confidence limits fell within the acceptable range (80-120%) for bioequivalence. Based on these data it was concluded that the two products showed comparable pharmacokinetic profiles and that the Dong-Kwang $\textrm{Tramcinolone}^{(R)}$ tablet is bioequivalent to the $\textrm{Ledercoat}^{(R)}$ tablet produced by Wyeth Korea.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.664-668
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• 2002

KR-31543,(2S,3R,4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amino]-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-2H-1-benzopyran is a new neuroprotetive agent for ischemia-reperfusion damage. The in vitro and in vivo metabolism of KR-31543 in rats has been studied by LC-electrospray mass spectrometry. Rat liver microsomal incubation of KR-31543 in the presence of NADPH resulted in the formation of a metabolite M1. M1 was identified as N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine on the basis of LC-MS/MS analysis with the synthesized authentic standard. Rat CYP3A1 and 3A2 are the major CYP isozymes involved in the formation of M1.

• Environmental Analysis Health and Toxicology
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• v.20 no.1
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• pp.47-55
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• 2005

본 연구는 GC/MS를 이용하여 수질, 토양 및 저질 시료 중의 benzo(a)pyrene(BaP)을 분석하는 방법을 확립하고자 하였다. BaP은 수질 시료(100mL)에서 n-hexane으로 추출하였으며, 토양 및 저질 시료(l0g) 에서는 먼저 메탄올로 추출한 후 hexane으로 다시 추출하여 농축시켜 분석하였다. 수질 시료 중의 BaP 회수율은 94.8% 이상이었으며 토양에서의 회수율은 약 93％를 보였고 재현성은 10.49% 이하였다. 검정 곡선은 상관계수(R²)값이 수질과 토양 모두에서 0.996 이상의 좋은 직선성을 보여주었다. 토양 시료의 경우 35지역 중 6지역의 토양에서 0.5～223.5㎍/kg의 농도 범위로 BaP가 검출되었으며 수질과 저질 시료에서는 모든 지역에서 검출한계 이하로 나타났다. 이 분석방법은 환경 중에 미량으로 존재하는 BaP의 분석과 모니터링에 유용하게 사용할 수 있는 적합한 방법이라 사료된다.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.416-420
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• 2003

The analytical method of antispasmodic agent tiropramide {$(\pm)\alpha$-(benzoylamino)-4-[2-(diethylamino)ethoxy]-N,N-dipropylbenzenepropanamide hydrochloride} was developed by gas chromatography/nitrogen-phosphorus detector (GC/NPD) in human plasma. Two kinds of tiropramide tablets were orally administered to volunteers by Latin square crossover design, and blood was withdrawn as designed schedule. The plasma of 1 mL was loaded on Sep-pak $C_{18}$ cartridge and eluted with methanol after washing with 30% methanol. The residue dissolved in 100 $\mu$L of methanol after evaporation was analyzed by GC/NPD. Precision (CV%) of intra-day was located within 2.6% and accuracy was less than 9.7%. Inter-day precision was below 8.7% and accuracy was relatively good as less than 14%. Plasma samples obtained from human volunteers were analyzed for the determination of tiropramide concentration by using this method. The method was sensitive, rapid and suitable enough to be applied for pharmacokinetic and bioequivalence studies of tiropramide in human volunteers.

• Analytical Science and Technology
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• v.16 no.1
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• pp.59-69
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• 2003

Benzophenone (BZP) and 4-nitrotoluene (4-NT) listed as endocrine disrupting chemicals are suspected to contaminate ground water sites and soil. Analytical method for simultaneous determination of the two chemicals in soil and ground water was developed by gas chromatography-mass spectrometry. Water (100 ml) was extracted with hexane, and soil (10 g) was extracted with methanol and hexane. Recovery in water was >72% for BZP and 90-118% for 4-NT. Recovery for 4-NT and BZP in soil was 51-59% with coefficient variation of less than 19.5%. Calibration curves showed a good linearity with $r^2=0.997$. In water and soil collected at nation-wide sites, BZP was found at 5 sites among 43 water sites at the concentration of $14.87{\pm}3.83ng/100 ml$. No 4-NT was found. It is suggested that this method is appropriate to the simultaneous quantitation of 4-NT and BZP in ground water and soil samples.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.232-237
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• 2003

The present study examined functional effects of a new selective phosphodiesterase type 5 inhibitor, 1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-thioxo-3-propyl-1H-pyrazolo[ 4,3]pyrimidin-5-yl)phenylsulphonyl]-4-methyl piperazine (KJH-1002), in the isolated rabbit corpus cavernosum (RCC). Relaxing effects of KJH-1002 were also compared with those of sildenafil, which is currently used as an oral therapy for penile erectile dysfunction. In the isolated RCC precontracted with phenylephrine, both KJH-1002 and sildenafil in the concentration range of 1 to 1000 nM, produced a comparable potentiation of the electical field stimulation-induced relaxation in a concentration-dependent manner. In the sodium nitroprusside (SNP)-induced relaxation, the $IC_{50}$/ values, concentrations of SNP required to produce a 50％ relaxation of the phenylephrine-induced contraction, were significantly decreased to the similar extent by treatments with KJH-1002 and sildenafil. The results suggest that a new selective phosphodiesterase type 5 inhibitor, KJH-1002, has an augmentative effect on penile erection comparable to that of sildenafil and can be useful for the treatment of erectile dysfunction.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.15-20
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• 2006

Genistein is a potent, plant-derived isoflavone that displays estrogenic activity at low concentrations but inhibits proliferation at high amounts. However, the molecular mechanism of genistein is not completely understood. In the present study, the biphasic effects (estrogenic and antiestrogenic activity) of genistein on the growth of MCF-7 cells were identified. Genistein within a low range of concentration, $1-10\;{\mu}M$, stimulated proliferation, while $50-100\;{\mu}M$ caused apoptotic cell death. Additionally, genistein at a low concentration induced estrogen receptor (ER)-mediated gene expression and ER phosphorylation. When pre-treated with PD98059, an MEK inhibitor, ER-mediated gene expression and ER phosphorylation by genistein were noticeably increased. However, the increased gene expression and phosphorylation did not enhance cell proliferation. Moreover, it was observed that ER-mediated signaling performs an important role in the MAPK pathway. The proliferation and apoptosis in genistein-treated MCF-7 cells were partially dependent on the Bcl-2 level. The addition of IC1 182, 780, an estrogen receptor antagonist, inhibited Bcl-2 expression induced by genistein. This study suggests that there is a close relationship between Bcl-2 and the ER signaling pathways in MCF-7 cells.

• Mass Spectrometry Letters
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• v.4 no.3
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• pp.55-58
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• 2013

Dioscin is a biologically active steroidal saponin with anticancer and hepatoprotective effects. A rapid, selective, and sensitive liquid chromatographic method with electrospray ionization tandem mass spectrometry was developed for the quantification of dioscin in rat plasma. Dioscin was extracted from rat plasma using ethyl acetate at acidic pH. The analytes were separated on a Halo C18 column using gradient elution of acetonitrile and 0.1% formic acid and detected by tandem mass spectrometry in selected reaction monitoring mode. The standard curve was linear ($r^2$ = 0.998) over the concentration range of 1-100 ng/mL. The lower limit of quantification was 1.0 ng/mL using 50 ${\mu}L$ of plasma sample. The coefficient of variation and relative error for intra- and inter-assay at four QC levels were 1.3 to 8.0% and -5.4 to 10.0%, respectively. This method was applied successfully to the pharmacokinetic study of dioscin after oral administration of dioscin at a dose of 29.2 mg/kg in male Sprague-Dawley rats.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.606-611
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• 2003

Byakangelicin, 9-(2,3-dihydroxy-2-methylbutoxy)-4-methoxy-7H- furo[3,2-g][l]benzopyran-7-one (BKG), a component of Angelicae dahuricae Radix, is considered to be an inhibitor of aldose reductase for the treatment of diabetic cataract. An analytical method for the isolation of BKG developed by high-performance liquid chromatography has been reported. No literature on the metabolism of BKG, however, has been found. With the purpose of identifying new metabolites of BKG, BKG (100 mg/kg) was orally administered to Sprague-Dawley rats via a gavage. Using a metabolic cage, urine was collected for 24 h, and the urine samples were extracted by liquid-liquid extraction. For structural identification of new urinary metabolites of BKG, various instrumental analyses were conducted by gas-chromatography/mass spectrometry, high-performance liquid chromatography/diode array detector, liquid chromatography/mass spectroscopy with thermospray interface and $^1H$ nuclear magnetic resonance spectroscopy. Two metabolites produced from the Ο-demethylation or Ο-dealkylation of BKG were newly identified, and another new but unknown metabolite was assumed to be the hydroxylated form of BKG. These results indicate that the major metabolic products of BKG are formed by Ο-demethylation or Ο-dealkylation of BKG side chains.

• The Korea Genome Conference
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• 2005.09a
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• pp.59-59
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• 2005