• Analytical Science and Technology
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• v.7 no.1
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• pp.103-114
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• 1994

The elution behaviors of Ni(II), Cu(II), Co(II), and Cr(II) in 1-phenyl-3-methyl-4(2-hydroxy-5-X-phenylazo)-5-pyrazolone, [Pm(2-OH)(5-X)PaPz](X=H, $CH_3$, $NO_2$, Cl) chelates have been studied by reversed phase HPLC. Thirteen metal-[Pm(2-OH)(5-X)PaPz] chelates were prepared and characterized by UV, IR, MS, and ICP spectroscopic methods. These metal-2-hydroxyarylazopyrazolone chelates were successfully separated on Novapak-$C_{18}$ column using methanol/water mixtures as a mobile phases. It was found that the chelates were eluted properly in an acceptable range of the capacity factor value($0{\leq}log\;k^{\prime}{\leq}1$). The dependence of the capacity factor(log k') on the volume fraction of water in the binary mobile phase showed a good linearity. Also, there was a good linear dependence of the capacity factor on the liquid-liquid extraction distribution ratio($D_c$) in methanol-water/n-pentadecane extraction system by the batch method. It suggested that the retention of the chelates in the reverse phase liquid chromatographic system be largely due to the solvophobic effect.

• Journal of Veterinary Clinics
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• v.8 no.2
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• pp.127-142
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• 1991

This study was carried out to investigate fatty liver in Korean black goats. Adult female goats were divided into 3 test groups(A, B and C). Group A and B of goats each received 3 test consecutive daily doses of DL-ethionine at 75mg/kg and 150mg/kg body weight, respectively. Group C of goats was given 3 consecutive doses of the compound every 48 hours at 150mg/kg body weight. The clinical symptoms, hematological values, serum chemical values and histopathological study of the liver were investigated in the test animals. The results obtained are as follows ; 1. Fatty liver were observed in every test animal. 2. Some clinical symptoms( anorexia, depression) were appeared from 1st day to 7th day after administration of the compound in every test animal. In addition to these symptoms, diarrhea and salivation were generally observed in test animals which were given the compound at 150mg/kg body weight. The degree of these symptoms was dose dependent. 3. There was no significant variations in total WBC counts and fibrinogen values in the blood of test goats. The PCV values were significantly increased on 5th day of dosing in group A and B of goats. 4. The total lipid value was not changed but the concentration of NEFA was significantly increased on 3rd day of dosing with the compound and returned to normal value after 10 days hereafter. The value of triglycerides was significantly increased on 1st day and returned to normal value on 3rd day of dosing. The value of cholesterol was significantly decreased on 3rd day and returned to normal value on 10th day after treatment. 5. Total protein level was decreased on 10th day of dosing in the groups of B and C, and billirubin level was significantly increased on 7th day of dosing in every test group and returned to normal level after 13th day of administration. 6. The activity of GGT in serum was not changed while the activities of SDH and AST were significantly increased in every test goat and those values were returned to normal after 10~13th day of trestment. 7 The 35K-protein fraction in serum was not detected by SDS-polyacrylamide gel electrophoresis, but this protein fraction was detected by the same method after treating the 21st and 22nd fraction which were obtained by column chromatography with Sephadex G-100. 8. The affected liver was congested and swollen on 3rd day, and yellowish brown in color and mottled appearance on 7th day of treatment. Histopathologically, fat droplets were common in the hepatocytes, this change was intensive on 7th day after treatment in group B and C. Hepatic cell necrosis was observed in some livers but this pathological change was disappeared and returned to normal after 13 days of treatment.

• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.437-443
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• 2005

A rapid, selective and sensitive reversed-phase HPLC method for the determination of a major metabolite of terfenadine, fexofenadine, in human serum was developed, validated, and applied to the pharmacokinetic study of terfenadine. Fexofenadine and internal standard, haloperidol were extracted from human serum by liquid-liquid extraction with acetonitrile and analyzed on a $Symmetry^{TM}$ C8 column with the mobile phase of 1% triethylamine phosphate (pH 3.7)-acetonitrile (67:33, v/v, adjusted to pH 5.6 with triethylamine). Detection wavelength of 230 nm for excitation, 280 nm for emission and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed fexofenadine concentration (50 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 10-500 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 10 ng/mL, which was sensitive enough for the pharmacokinetic studies of terfenadine. The overall accuracy of the quality control samples ranged from 95.70 to 114.58% for fexofenadine with overall precision (% C.V.) being 3.53-14.39%. The relative mean recovery of fexofenadine for human serum was 90.17%. Stability studies (freeze-thaw, short-term, extracted serum sample and stock solution) showed that fexofenadine was stable during storage, or during the assay procedure in human serum. However, the storage at $-70^{\circ}C$ for 4 weeks showed that fexofenadine was not stable. The peak area and retention time of fexofenadine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of fexofenadine in human serum samples for the pharmacokinetic studies of orally administered Tafedine tablet (60 mg as terfenadine) at three different laboratories, demonstrating the suitability of the method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.140-148
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• 1994

Indentification of IMP was carried out and changes in ATP breakdown products during storage at $0^{\circ}C\;ad\;20^{\circ}C$ were investigated in the muscles of ascidian Halocynthia roretzi. For identifying IMP, the ion-exchange column chromatographic method was applied to the perchloric acid extract of the muscle of cultured ascidian collected at the southern coast near Chungmu of Korea in April 1989. The IMP of sample was eluted a little earlier than that of the reference standard, but absorption spectra of both fractions agreed each other. In addition, both fractions gave the identical retention time of HPLC. These results reconfirmed that the ascidian muscle did contain IMP, indicating that ATP was degraded through IMP breakdown pathway, such as $ATP{\to}ADP{\to}AMP{\to}IMP{\to}Ino{\to}Hyp$. Ado was detected in some samples and IMP was detected throughout the experimental periods at both temperatures, but their levels were always very low; they did not increase significantly even when the decreasing rate of AMP was very rapid and concomitant remarkable increase in Ino were observed at the early stage of storage. Those changes in ATP suggest that AMP deaminase activity was present in the ascidian muscle, though it was very low. The main breakdwon pathway of ATP was assumed to be $ATP{\to}ADP{\to}AMP{\to}Ado{\to}Ino{\to}Hyp$. In conclusion, there were two breakdown pathways of ATP in the muscle of ascidian as was the case for the muscle of many marine crustaceans.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.78-86
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• 1997

To clarify the phytoplankton blooms in Lake Shihwa after the construction of a dyke, a study on the environmental factors, the distribution of chlorophyll-a, phytoplankton standing stocks, dominant species and primary productivity was carried out in Lake Shihwa and adjacent coastal areas from October, 1995 to August, 1996. Lake Shihwa is brackish water with mixing of freshwater from tributaries and the remaining salt water at the bottom. The dense phytoplankton bloom of average value of 168.6 ${\mu}gChl-a\;l^{-1}$ have occurred throughout the year in Lake Shihwa which is eutrophicated by the large input of nutrients from inflowing 5 tributaries and Shihwa Industrial Complex. The major organisms of algal bloom in Lake Shihwa were diatoms, Cyclotella atomus, Nitzschia sp. and Chaetoceros sp. in autumn and winter, and dinoflagellate Prorocentrum minimum and Chrysophyceae in spring and summer. The autumn and winter diatom blooms were limited by the depletion of silicate in the lake. Diatom blooms have occurred in the coastal areas adjacent to Shihwa lake from winter to summer due to the inflow of nutrient rich-water from Lake Shihwa. The primary productivities in the Lake Shihwa ranged from 2,653 mgC $m^{-2}\;day^{-1}$ to 9,505 mgC $m^{-2}\;day^{-1}$ with an average of 3,972 mgC $m^{-2}\;day^{-1}$. However, most of the high primary production was limited to the shallow euphotic zone due to the inhibition of light penetration. The primary productivities during autumn and winter were limited by the depletion of silicate. Lack of photosynthesis and the decomposition of falling organic matter under the middle of water column accelerated the depletion of dissolved oxygen in the bottom layer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.2
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• pp.101-106
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• 1999

The down-core distribution of chlorophyll a, organic carbon contents and ${\delta}^{13}C$ in the bottom sediments were measured to understand the evolution of eutrophication in Masan Bay. Bottom sediment were collected in January 1994. The chlorophyll a and organic carbon contents in the sediment core decreased with increasing sediment depth, respectively. Bottom sediments (0~20 cm) in Masan Bay was rich in chlorophyll a (avg. 9.6 ${\mu}g\;g^{-1}$ dryweight) and organic C (avg. 2.5%). The down-core distribution of chlorophyll a suggests that the inner part of Masan Bay has experienced the acceleration of chlorophyll a supply since 1960s. Flux of organic carbon to the sea floor is in the range of 10 $gCm^{-2}\;yr^{-1}$ assuming the C:Chl a ratio of 25. It suggests tht approximately 1.3% of the fixed carbon by phytoplankton appears to be deposited in the bottom sediments.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.285-290
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• 1994

About 500 bacterial and fungal strains from a wide variety of natural habitats were screened for a new type II restriction endonuclease. Among the 500 species, we selected one species that produced a new restriction endonuclease. This strain has an optimum temperature of $30^{circ}C$ for growth. Morphological, cultural, and physiological characteristics were examined for identification of the isolated strain J-482. This strain was found to belong to the genus Alcaligenes. The restriction endonuclease was named as AspJI and partially purified from Alcaligenes sp. J-482 by DEAE-Sephadex A-50 column chromatography and gel filtration. Most of other nucleases were removed by the purification steps. The AspJI has a substrate specificity to ${lambda}$ DNA, pBR322 and Adenovirus-2 DNA. For its maximal activity, the isolated enzyme requires $MgCl_2$, which should be at least 12.5 mM and it does not need any other cofactors. It is maximally active in the absence of NaCl and is completely inactivated at 100 mM NaCl. The pH and temperature optima for activity were pH 7.5 and $37^{circ}C$, respectively. The DNA fragments generated by digesting ${lambda}$ DNA, pBR322, and Adenovirus-2 DNA with AspJI were the same as that produced by AatII. This suggests that AspJI is an isoschizomer of AatII.

• Analytical Science and Technology
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• v.31 no.6
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• pp.225-231
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• 2018

Benzoic acid, methyl paraben, and butyl paraben are preservatives that have been used in pharmaceutical, cosmetic, and food products. However, as their toxicities for human have been reported, many nations and organizations including Korea have established a regulation limit for thier usage of these preservatives in food products. The present study developed the isotope dilution liquid chromatography mass spectrometry method for accurate determination of three target preseratives in soysauce. In this study, the isotope dilution liquid chromatography mass spectrometry method was developed for accurate determination of three target preservatives in soy sauce. LC separation was optimized considering the pKa of benzoic acid which is lower than those of methyl and butyl parabens. A C18 column was used with 5 mM ammonium acetate and methanol as mobile phases. Mass spectrometry was operated in negative mode and selected reaction monitoring mode (SRM). Soy sauce sample was cleaned-up with C18 SPE cartridge for removing matrix inferences and color material. Optimized conditions and the method were validated with soy sauce reference materials for the analysis of food preservatives from Health Science Authority in Singapore. The measured values of benzoic acid, methyl and butyl paraben agreed well with reference values within their uncertainties.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1191-1197
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• 2000

In the preliminary study, we investigated the anti-complementary activities of 62 extracts from Korean edible seaweeds. Of those, Pachymeniopsis elliptica showed the highest anti-complementary activity. Therefore, it was purified as follows; i) PE-1 by ethanol precipitation, ii) PE-1-C by ultrafiltration, iii) PE-1-CIV by DEAE-Toyopearl 650C, and iv) PE-1-CIV-ii by Sepharose CL-6B. The purified compound, PE-1-CIV-ii, was the complexed homogeneous polysaccharide (molecular mass: 780 kDa) with 82.9% of anti-complementary activity. Also, it contained a significant amount of sulfate group (30.5%), which indicated it as a sulfated algal polysaccharide. Its structural monosaccharides were galactose (44.3%), 3,6-anhydrogalactose (34.0%), glucose (8.2%), fucose (5.4%), xylose (5.2%) and rhamnose (2.9%). After the treatment of periodate on a sample, a significant decrease in anti-complementary activity was found, which was a characteristic of bioactive polysaccharides. And-tumor activity of PE-1-A, B and C was tested in the sarcoma-180 solid tumor model. The PE-1-C with the largest molecular mass (more than 300 kDa) showed 81% of inhibition on the solid tumors, suggesting that the anti-complementary activity was, at least in part, related to anti-tumor activity. Based upon these results, the purified polysacchardes could be an immunopotentiator in vivo.

• ALGAE
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• v.19 no.1
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• pp.49-57
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• 2004

This study was performed to obtain basic information on the ecology of Zostcra marina and to promote efficient conservation of this species which has been decline in Gamak Bay, Yeosu, Korea. Whater column characteristics and eelgrass morphology at Anpori, Jangsuri and Wonpori were investigated every month from December 1999 to November 2000. The water temperature, salinity and pH at the three sites were 10.0-27.0${\circ}C$,29.4-34.7% and 8.1-8.5, respectively. The water temperature at Anpori tended to be slightly lower than that at the other locations; the salinity at Wonpori from July to November was a little lower than that of the other locations. The concentrations of $NO_2$-N, $NO_3$_N, $NH_4$-N, $PO_4$-P and $Si(OH)_4$-Si at the three sites were 0.9-1.3, 2.0-6.2, 7.8-9.0, 3.0-3.6 and 22.2-30.2 uM, respectively. The concentration of $NO_3$-N at Wonpori from June to November was somewhat lower than that at the other locations; that of NH4-N at Jansuri was somewhat lower than the others. The mean shoot height and leaf width of the Anpori, Jangsuri and Wonpori populations were 80.6 cm and 0.9 mm, 90.0 cm and 1.0 mm, and 95.3 cm and 1.0 mm, respectively. The mean total shoot weight of the Anpori, Jangsuri and Wonpori ones was 24.5,31.0 and 29.7 & respectively. The mean leaf and branch numbers of the Anpori, Jangsuri and Wonpori populations were 16.5 and 2.6, 16.1 and 2.4 and 15.4 and 2.6 individuals, respectively. The correlation coefficients between shoot height and water temperature, leaf width and total shoot weight, leaf number and branch number, and $Si(OH)_4$-Si and $NO_3$-N were 0.726, 0.692, 0.862, and 0.693, respectively. The coefficients between shoot height and $NO_3$-N, total shoot weight and NO_3$-N, water temperature and $Si(OH)_4$-Si, water temperature and salinity, and water temperature and $NO_3$-N were -0.716, -0.536, -0.775, -0.685 and -0.685, respectively. The first four principal components explain 71.1% of the total sample variance. For axis 1, shoot height and water temperature tended to correlate with the population of Jansuri, followed by the Wonpori population, and $Si(OH)_4$-Si and $NO_3$-N tended to correlated strongly with the Anpori population. For axis 2, total weight, leaf width, leaf number and branch number showed a tendency to correlate with the Anpori and Jangsuri populations. For axis 3, the Anpori population tended to be influenced by $NO_2$-N and $PO_4$-P. For axis 4, the Wonpori and Jangsuri populations tended to be affected by salinity. The tendency, however, differed according to season.