• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.636-643
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• 2009

Residual fluoroquinolone levels in animal foods retailed in Korea were monitored according to the method outlined in Korea Food Code using HPLC-FLD and HPLC-ESI-MS/MS for confirmation. The optimum ion transitions were $360{\rightarrow}316$, 342 m/z for enrofloxacin, $332{\rightarrow}314$, 288 m/z for ciprofloxacin, $320{\rightarrow}301$, 230 m/z for norfloxacin, $334{\rightarrow}315$, 290 m/z for pefloxacin, $362{\rightarrow}318$, 261, 334 m/z for ofloxacin, and $262{\rightarrow}201$, 126 m/z for flumequin. Enrofloxacin, ciprofloxacin and norfloxacin residues were found in 12 out of 388 samples. These antibiotics were only found in chicken samples, while no residues were found in beef, pork, milk and egg samples. Using this monitoring method, detection rates of 3.1, 1.3, and 0.3% were obtained for enrofloxacin, ciprofloxacin and norfloxacin, respectively. The levels of enrofloxacin, ciprofloxacin and norfloxacin detected in food samples ranged from 0.01 to 0.73 mg/kg in 12 samples, 0.01-0.03 mg/kg in 5 samples, and 0.12 mg/kg in only a sample, respectively.

• Journal of Life Science
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• v.11 no.5
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• pp.447-456
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• 2001

We have recently demonstrated that the fluoroquinolone antibacterial DW-116 caused a significant developmental toxicity in rats. The present study was conducted to determine whether the development toxicity induced by DW-116 treatment was the result of malnutrition fro reduced food intake or the direct effects of test chemical on conceptuses. The test chemical was administered by gavage to pregnant rats from gestational days 6 through 16 at dose levels of 0 and 500 mg/kg/day. A pair-feeding study was also performed in which the pregnant rats received the same amount of diet consumed by the DW-116-treated pregnant rats. All dams were subjected to caesarean section on day 20 of gestation and their fetuses were examined for examined for external, visceral, and skeletal abnormalities. In this treatment group, the maternal toxicities included increased abnormal clinical signs, decreased maternal body weight, suppressed body weight gain during treatment and posttreatment periods, and reduced food intake. The significant developmental toxicities included increased fetal deaths, decreased live fetuses, reduced fetal body weight and placental weight, increased incidence of fetal abnormalities, and increased fetal ossification delay. In this pair-fed group, however, slight maternal toxicities including decreased body weight and suppressed body weight gain during treatment period were observed in comparison with the control group, and minimal development toxicities including reduced fetal and placental weights and increased fetal ossification delay were found. The number of fetal deaths and live fetuses, and the incidences of malformed fetuses and litters with affected fetuses were comparable to the control values. Based on the results, it could be concluded that the development toxicity observed in the treatment group is attributable to the direct effects of Dw-116 treatment, but not to the maternal malnutrition from reduced food consumption during pregnancy.

• Tuberculosis and Respiratory Diseases
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• v.72 no.1
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• pp.44-49
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• 2012

Background: Multidrug-resistant tuberculosis (MDR-TB) is an increasing public health problem and poses a serious threat to global TB control. Fluoroquinolone (FQ) and aminoglycoside (AG) are essential anti-TB drugs for MDR-TB treatment. REBA MTB-FQ$^{(R)}$ and REBA MTB-KM$^{(R)}$ (M&D, Wonju, Korea) were evaluated for rapid detection of FQ and kanamycin (KM) resistance in MDR-TB clinical isolates. Methods: M. tuberculosis (n=67) were isolated and cultured from the sputum samples of MDR-TB patients for extracting DNA of the bacilli. Mutations in genes, gyrA and rrs, that have been known to be associated with resistance to FQ and KM were analyzed using both REBA MTB-FQ$^{(R)}$ and REBA MTB-KM$^{(R)}$, respectively. The isolates were also utilized for a conventional phenotypic drug susceptibility test (DST) as the gold standard of FQ and KM resistance. The molecular and phenotypic DST results were compared. Results: Sensitivity and specificity of REBA MTB-FQ$^{(R)}$ were 77 and 100%, respectively. Positive predictive value and negative predictive value of the assay were 100 and 95%, respectively, for FQ resistance. Sensitivity, specificity, positive predictive value and negative predictive value of REBA MTB-KM$^{(R)}$ for detecting KM resistance were 66%, 94%, 70%, and 95%, respectively. Conclusion: REBA MTB-FQ$^{(R)}$ and REBA MTB-KM$^{(R)}$ evaluated in this study showed excellent specificities as 100 and 94%, respectively. However, sensitivities of the assays were low. It is essential to increase sensitivity of the rapid drug resistance assays for appropriate MDR-TB treatment, suggesting further investigation to detect new or other mutation sites of the associated genes in M. tuberculosis is required.

• Journal of Microbiology
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• v.43 no.5
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• pp.391-397
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• 2005

Escherichia coli is a common inhabitant of the intestinal tracts of animals and humans. The intestines of animals also represent an ideal environment for the selection and transfer of antimicrobial resistance genes. The aim of this study was to investigate the resistance of E. coli isolated from chicken fecal samples to fluoroquinolones and to analyze the characterization of mutations in its gyrA and parC gene related resistance. One hundred and twenty-eight E. coil isolates showed a high resistance to ciprofloxacin (CIP; $60.2\%$), enrofloxacin (ENO; $73.4\%$) and norfloxacin (NOR; $60.2\%$). Missense mutation in gyrA was only found in the amino acid codons of Ser-83 or Asp-87. A high percentage of isolates ($60.2\%$) showed mutations at both amino acid codons. Missense mutation in parC was found in the amino acid codon of Ser-80 or Glu-84, and seven isolates showed mutations at both amino acid codons. Isolates with a single mutation in gyrA showed minimal inhibitory concentrations (MIC) for CIP (${\le}0.5\;to\;0.75{\mu}g/ml$), ENO (1 to $4{\mu}g/ml$) and NOR (0.75 to $4{\mu}g/ml$). These MIC were level compared to isolates with two mutations, one in gyrA and one in parC, and three mutations, one in gyrA and two in parC (CIP, ${\le}0.5\;to\;3{\mu}g/ml;\;ENO,\;2\;to\;32<{\mu}g/ml;\;NOR,\;1.5\;to\;6\;{\mu}g/ml$). However, the isolates with two mutation in gyrA regardless of whether there was a mutation in parC showed high MIC for the three fluoroquinolones (CIP, 0.75 to $32{\le}{\mu}g/ml;\;ENO,\;3\;to\;32{\le}{\mu}g/ml;\;NOR,\;3\;to\;32{\le}{\mu}g/ml$). Interestingly, although the E. coil used in this study was isolated from normal flora of chicken, not clinical specimens, a high percentage of isolates showed resistance to fluoroquinolones and possessed mutations at gyrA and parC associated with fluoroquinolone resistance.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.6-11
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• 1997

• Biomolecules & Therapeutics
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• v.5 no.2
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• pp.187-193
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• 1997

The in vivo and in vivo antibacterial activity of DW-116, a newly synthesized fluoroquinolone, were compared with those of other quinolones. DW-116 exhibited more potent antibacterial activity than rufloxacin and lower activity than ofloxacin and ciprofloxacin in in vivo assay But, DW-116 particularly showed strong activity against the family of staphylococci including methicillin-sensitive staphylococcus and its activity was more active than that of ciprofloxacin. The time-kill curve studies showed rapid bactericidal activity for DW-116. The post-antibiotic effect of DW-116 was observed between 0.66 and 5 hours. The therapeutic efficacy of DW-116 against respiratory infection with P. aeruginosa was as strong as that of ciprofloxacin and its effect against urinary tract in(traction with E. coli was more effective than rufloxacin. The excellent therapeutic efficacy of DW-116 against these local infections is due to its good pharmacokinetic profiles.

• Biomolecules & Therapeutics
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• v.5 no.2
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• pp.179-186
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• 1997

The pharmacokinetics and tissue distribution of DWP20373, a novel fluoroquinolone, were examined in rats and beagle dogs after a single intravenous and oral administration. Analysis of DWP20373 in plasma, tissue, and urine was performed by both HPLC and microbiological assay. The plasma drug concentration declined biexponentially both rats and beagle dogs. In the rats, the terminal drug elimination half-life (t$_{1}$2$\beta$/) was 64 min (IV) and 57 min (PO) by bioassay, and 76 min (IV) and 77 min (PO) by HPLC. Whereas in beagle dogs, t$_{1}$2$\beta$/ was 196 min (IV) and 350 min (PO). The volume of distribution at steady-state (Vd$_{ss}$ ) was 811 ml/kg (bioassay) and 2061 ml/kg (HPLC) in rats, and 2738 ml/kg (bioassay) in beagle dogs. The total body clearance (Cl$_{t}$) of DWP20373 was 10 ml/min/kg (bioassay) and 7 ml/min/kg (HPLC) in rats, and 11 m1/min/kg (bioassay) in beagle dogs. The extent of bioavailability after oral administration was 49% (bioassay) and 67% (HPLC) in rats, and 84% (bioassay) in beagle dogs. The 24-h urinary recovery, measured by bioassay, was 2.7% after oral dosing and 5.5% after intravenous dosing in rats. Serum protein binding ratio determined at 27g/ml was 78%. This drug was also distributed in tissues in the decreasing order of liver, kidney, spleen, lung, heart, and muscle determined at 30 min after oral administration.on.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.744-748
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• 2010

2,3,4,5-Tetrafluorobenzoic acid, an important intermediates of fluoroquinolone antibiotics, was synthesized from tetrachloride phthalic anhydride through imidation, fluorination, hydrolysis and decarboxylation. The effects of phase transfer catalyst on imidation and fluorination reaction and the effects of surfactants on the hydrolysis reaction were studied, respectively. Experimental results showed that the imidation reaction time was greatly reduced in the presence of a phase transfer catalyst, hexadecyltrimethyl, resulting in imidation yield as high as 98.2%. The fluorination yield reached 81.3% when tetrabutylammonium bromide was chosen as a phase transfer catalyst. The hydrolysis reaction time was also decreased by adding hexadecyltrimethyl while increasing the yield to 88.6%. In the post-processing, the sublimation method was used to purify the product, and ideal effect was obtained. In the decarboxylation reaction, tetrafluoride phthalic acid was obtained by decarboxylation in the solvent of tri-n-butyl amine and decarboxylation yield reached 81.6%. Compared with the literature method, the overall reaction time of the improved method decreased from 53 h to 20.5 h and the total yield increased from 47.3% to 57.4%.

• YAKHAK HOEJI
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• v.41 no.2
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• pp.225-232
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• 1997

The in vitro antibacterial activity of DWP20367 (1-Cyclopropyl-6-fluoro-8-chloro-7-(2,7-diazabicyclo[3,3,0]oct-4-ene-7-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid), a new broad-spectrum fluoroquinolone, was compared with those of ciprofloxacin (CPFX), sparfloxacin (SPFX) and ofloxacin (OFLX). DWP20367 was showed antibacterial activity much higher than CPFX, SPFX and OFLK against gram-positive bacteria, while it was slightly more superior to quinolones against gram-negative bacteria. DWP20367 was particularly effective against MRSA, and its $MlC_{90}$ against clinical isolates of methicillin-susceptible S. aureus, low methicillin-resistant S. aureus and high methicillin-resistant S. aureus were 0.098, 0.781 and 1.563 micro g/ml, respectively. Against S. pneumoniae, MIC90 of DWP20367 was 2- to 8-fold higher than those of CPFX. With a view of MIC90, DWP20367 showed slightly more potent activity against P. aeruginosa and E. coli isolates than the control quinolones. DWP20367 activity was not affected by inoculum size and medium pH. But addition of $Mg^{2+}, \;Ca^{2+} $Mg2+, Ca2+ or horse serum (25%) decreased its antibacterial activity. DWP20367 was showed rapidly bactericidal activity within 2 to 4 h, and regrowth was not observed even after 24 h incubation at concentrations near the 4-fold of MIC.

• Biomolecules & Therapeutics
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• v.10 no.1
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• pp.43-49
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• 2002

The present study was conducted to investigate the placental transfer and pharmacokinetics of the flu-oroquinolone antibacterial DW-116 in pregnant rats. The placental transfer and pharmacokinetics of DW-116 were examined after a single oral dose of 500 mg $^{14}C$ DW-116/kg on gestational day 18. Maternal and fetal tissues were collected at 0.17 0.5,1,2,4,8, and 24 h after dosing. Maximum radioactivity was detected in maternal plasma, placenta, and whole fetus at 1 h, and in amniotic plasma at 4 h after dosing. Thereafter, radioactivity gradually disappeared from these tissues and was 16~28% of maximum levels at 24 h after dosing. Radioactivity in whole fetus were higher than those in the maternal plasma and placenta. The $T_{1/2,abs}$, $T_{1/2,{\beta}},$ AUC, $T_{max},$ and $C_{max}$ in the maternal plasma were approximately 6 min, 13.3 h, 1620 $ug^*hr/ml,$ 0.5 h, and 136 ug/ml, respectively. Those in the placenta were approximately 20 min, 12.3 h, 2150 $ug^*h/$m\ell$,$ 1.0 h, and 172 ug/ml, respectively. Those in the whole fetus were 13 min, 12.8 h,2549 $ug^*h/$m\ell$,$ 1 h, and 191 ug/ml, respectively. In the amniotic fluid of maternal uterus, the 4T_1/2,abs}$, $T1/2,{\beta},$ AUC, $T_{max},$ and $C_{max}$ were approximately 1.3 h,9.3 h,2508 $ug^*h/$m\ell$,$ 4.4 h, and 135 ug/ml, respectively. While DW-116 disappeared biphasically from maternal plasma, whole fetus and placenta, it was eliminated monophasically from amniotic fluid. In conclusion, this study demonstrated that the absorption and distribution of DW-116 in maternal plasma and placenta were extensively rapid, and that the test chemical well passed the blood-placenta barrier and was transferred to the fetus.