• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.155-160
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• 1999

Studies on detoxification of Paralytic Shellfish Poison (PSP)-infested oyster, Crassostrea gigas were carried out using available processing resources. Changes of paralytic shellfish toxin components and specific toxicity during canning process were also investigated with high performance liquid chromatography (HPLC). Toxic oysters collected at Hachong in Koje Bay were used for experimental samples. The toxicity of oysters with range of 185-778 ug/100g was reduced below the quarantine limit of 80 ug/100g or not detected level by the mouse bioassay after canning process. The mole $\%$ of toxin components in the shucked oyster was in the order of 25.1 mole $\%$ of gonyautoxin 1, 19.2 mole $\%$ of gonyautoxin 3, 17.2 mole $\%$ of gonyautoxin 4 and 14.6 mole $\%$ of gonyautoxin 2. This sample had tracing amounts of Cl, C2, saxitoxin and neosaxitoxin. In the case of specific toxicity, the major toxins were consisted of gonyautoxin 1-4. The sum of gonyautoxin 1, 2, 3 and 4 was 80% of total toxicity of oyster. Saxitoxin and decarbamoylsaxitoxin were the more thermostable than any other toxin components.

• 한국수산과학회지
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• 제29권6호
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• pp.900-908
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• 1996

Changes of paralytic shellfish toxin components and specific toxicity in blue mussel, Mytilus edu/is and oyster, Crassostrea gigas during canning process were investigated by high performance liquid chromatography (HPLC). The $mole\%$ of the frozen shucked blue mussel were in order of $27.5\;mole\%$ of gonyautoxin 1, $23.0\;mole\%$ of gonyautoxin 8 (C1) and $23.0\;mole\%$ of epi-gonyautoxin 8 (C2), while those of the frozen shucked oyster were in order of $29\;mole\%$ of C1, $22\;mole\%$ of C2, $16.7\;mole\%$ of gonyautoxin 2. Both samples had minor amounts of saxitoxin and neosaxitoxin. On the other hand, in case of specific toxicity, the major toxins were consisted of gonyautoxin $1\~4$ in both sample. The toxicity of gonyautoxin $1\~4$ were 88 and $84\%$ in blue mussel and oyster, respectively. According to the experimental results, C1, C2 and gonyautoxin 4 were very sensitive to heat treatment, while gonyautoxin 2 and saxitoxin were pretty heat resistant than any other toxin components.

• Archives of Pharmacal Research
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• 제27권6호
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• pp.633-639
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• 2004

The expression of therapeutic transgenes in recombinant adenoviral vectors is a major cause of toxicity in dividing cancer cells as well as non dividing normal cells. To solve the problem of toxicity to normal cells, we have reported on a recombinant adenoviral vector system （AdLP-） in which the expression of the transgene is directed by the tumor-specific L-plastin promoter （LP） （Chung et al., 1999）. The object of this study was to generate a recombinant adenoviral vector system which would generate tumor cell specific expression of cytosine deaminase （CD） gene. We report the construction of a replication-incompetent adenoviral vector in which CD is driven by the L-plastin promoter （AdLPCD）. Infection of 293 cells by AdLPCD generated the functional CD protein as measured by HPLC analysis for the conversion of 5-Fluorocy-tosine （5-FC） to 5-Fluorouracil （5-FU）. HPLC analysis in conjunction with counting radioactivity for ［6-$^3$H］-5FC and ［6-$^3$H］-5FU demonstrated vector dose-dependent conversion of 5-FC to 5-FU in AdLPCD infected ovarian cancer cells. The results from present and previous studies（Peng et al., 2001； Akbulut et al., 2003） suggest that the use of the AdLPCD／5-FC system may be of value in the treatment of cancer including microscopic ovarian cancer in the peritoneal cavity.

• The Plant Pathology Journal
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• 제20권1호
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• pp.52-57
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• 2004

Sclerotinia sp. (isolate BWC98-105) causes stem blight and root rot in Leghum sp., and is presently being evaluated as a potential mycoherbicide for the control of Trifoliorium repens. Bioassays have shown that Sclerotinia sp. produces phytotoxic substance which is biologically active against T. repens. Two biologically active compounds, designated as compoundsI and II, were produced in vitro from the culture filtrate of BWC98-105 isolate Sclerotium sp. Compounds I and II were purified by means of liquid-liquid extraction and $C_{18}$ open column chromatography (300 ${\times}$ 30 mm, i.d). To determine the purity, the purified compounds were analyzed by RP-HPLC. The analytical RP-HPLC column was a TOSOH ODS-120T (150 ${\times}$ 4.6 mm i.d, Japan), of which the flow rate was set at 0.7 mL/min using the linear gradient solvent system initiated with 15 % methanol to 85 % methanol for 50 min with monitoring at 254 nm. Under these RP-HPLC conditions, compounds I and II eluted at 3.49 and 4.13 min, respectively. Compound II was found to be most potent and host specific. However, compound I had a unique antibiotic activity against phytopathogenic bacteria like bacterial leaf blight (Xanthomonas oryzae) on rice, where it played a less important role in producing toxicity on T. repens. No toxin activity was detected in the water fraction after partitioning with several organic solvents. However, toxin activity was detected in the ethyl acetate and butanol fractions. In the leaf bioassay using compound II, the disease first appeared within 4-5 h as water soaked rot, which subsequently developed into well-defined blight affecting the whole plant.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.85-94
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• 2015

RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) is the most important explosive contaminant, both in concentration and in frequency, at military shooting ranges in which green technologies such as phytoremediation or constructed wetlands are the best option for mitigation of explosive compounds discharge to the environment. A study was conducted with two identical lab-scale plug flow constructed wetlands planted with Amur silver grass to treat water artificially contaminated with 40 mg/L of toxic explosive compound, RDX. The reactor was inoculated with or without RDX degrading mixed culture to evaluate plant-microorganism interactions in RDX removal, transformation products distribution, and kinetic constants. RDX and its metabolites in water, plant, and sediment were analyzed by HPLC to determine mass balance and kinetic constants. After 30 days of operation, the reactor reached steady-state at which more than 99% of RDX was removed with or without the mixed culture inoculation. The major transformation product was TNX (Trinitroso-RDX) that comprised approximately 50% in the mass balance of both reactors. It was also the major compound in the plant root and shoot system. Acute toxicity analysis of the water samples showed more than 30% of toxicity reduction in the effluent than that of influent containing 40 mg/L of RDX. In the Amur silver grass mesocosm seeded with the mixed culture, the specific RDX removal rate, that is 1st order removal rate normalized to plant fresh weight, was estimated to be 0.84 kg⁻¹ day⁻¹ which is 16.7% higher than that in the planted only mesocosm. Therefore, the results of this study proved that Amur silver grass is an effective plant for RDX removal in constructed wetlands and the efficiency can be increased even more when applied with RDX degrading microbial consortia.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1164-1170
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• 2006

A triptolide-lysozyme (TP-LZM) conjugate was synthesized to achieve renal specific delivery and to reduce the side effects of triptolide. Triptolide was coupled to lysozyme through succinic via an ester bond with an average coupling degree of 1 mol triptolide per 1 mol lysozyme. The lysozyme can specifically accumulate in the proximal tubular cells of the kidney, making it a potential carrier for targeting drugs to the kidney. The structure of triptolide succinate (TPS) was confirmed by IR, $^{1}H-NMR$, MS and UV. The concentrations of triptolide in various samples were determined by reversed-phase high-performance liquid chromatography (HPLC). In this study, the physicochemical and stability profiles of TP-LZM under various conditions were investgated the stability and releasing profiles of triptolide-lysozyme (TP-LZM) under various conditions. In vitro release trails showed triptolide-lysozyme was relatively stable in plasma (less than 30% of free triptolide released) and could release triptolide quickly in lysosome (more than 80% of free triptolide released) at $37^{\circ}C$ for 24 h. In addition, the biological activities of the conjugate on normal rat kidney proximal tubular cells (NRK52E) were also tested. The conjugate can effectively reduce NO production in the medium of NRK52E induced by lipopolysaccharide (LPS) but with much lower toxicity. These studies suggest the possibility to promote curative effect and reduce its extra-renal toxicity of triptolide by TP-LZM conjugate.

• Archives of Pharmacal Research
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• 제24권1호
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• pp.55-63
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• 2001

Aucubin, an irdoid g1ucoside, was investigated to determine whether it has a stimulating effect on $\alpha$-amanitin excretion in $\alpha$-amanitin intoxicated rats, and whether there is binding activity to calf thymus DNA. High-performance liquid chromatography (HPLC) analysis of $\alpha$-amanitin in rat urine allowed quantitative measurement of the $\alpha$-amanitin concentration with a detection limit of 50${mu}g/ml$. In this system, a group treated with both $\alpha$-amanitin and aucubin showed that o(-amanitin was excreted about 1.4 times faster than in the $\alpha$-amanitin only treated group. Our previous results showed that the toxicity of $\alpha$-amanitin is due to specific inhibition of RNA polymerase activity and the resultant blockage of the synthesis of certain RNA species in the nucleus. However, no significant activity change on RNA polymerase from Hep G2 cells was observed when aucubin was treated with $\alpha$-amanitin at any concentration tested. Nevertheless, aucubigenin inhibited both DNA polymerase (IC50, 80.5${mu}g/ml$) and RNA polymerase (IC50, 135.0${mu}g/ml$) from the Hep G2 cells. The potential of both $\alpha$-amanitin and aucubin to interact with DNA were examined by spectrophotometric analysis. $\alpha$-Amanitin showed no significant binding capacity to calf thymus DNA, but aucubin was found to interact with DNA, and the apparent binding constant ($K_{app}$) and apparent number of binding sites per D7A phosphate ($B_{app}$) were 0.45$0.45{\times}$$10^4$ $M^{-1}$ and 1.25, respectively.

• Toxicological Research
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• 제23권2호
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• pp.143-150
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• 2007

Although animal and epidemiological studies have suggested oxidative stress as an etiological factor in pathogenesis including cancer, inflammation, sepsis, fibrosis, cardiovascularlneurodegenerative diseases and aging-related disorders, conflicting results have been obtained in clinical trial with antioxidants. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating antioxidant capacity. The antioxidant activity of a series of sugar alcohols against peroxyl radicals, hydroxyl radicals and peroxynitrites was determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. Specific TOSC values calculated from the slope of the linear regression for erythritol, xylitol, sorbitol or mannitol against peroxyl radicals was $2.1{\pm}0.2,\;3.7{\pm}0.3,\;9.1{\pm}0.3$ or $8.7{\pm}1.1$ TOSC/mM, respectively. Specific TOSC values for erythritol, xylitol, sorbitol or mannitol against peroxynitrite was $1.9{\pm}0.3,\;3.9{\pm}0.4,\;7.8{\pm}0.7$ or $7.7{\pm}0.5$ TOSC/mM, respectively. These results suggest that oxy-radical scavenging capacity is dependent on the number of aliphatic hydroxyl group in sugar alcohols of monosaccharide. Tert-butylhydroperoxide (t-BHP)-induced cell toxicity determined by MTT assay was marginally attenuated by 10 mM erythritol, but completely inhibited by 10 mM xylitol, 2 mM sorbitol or 0.75 mM maltitol, a disaccharide alcohol. Oxidative stress markers, such as glutathione (GSH) and malondial-dehyde (MDA) levels, were measured in t-BHP-treated cells using HPLC equipped with a fluorescence detector and a reverse phase column. Erythritol did not change the levels of GSH and MDA in H411E cells treated with t-BHP. The t-BHP-induced changes in cellular GSH and MDA levels were ameliorated by 10 mM xylitol and completely blocked by 10 mM sorbitol and maltitol. These results indicate that sugar alcohols protect cells against oxidative stress via scavenging oxy-radical and suggest that TOSC assay in conjunction with cell-based assay is a valid method for evaluating antioxidant capacity of natural and synthetic chemicals.

• 한국식품위생안전성학회지
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• 제27권1호
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• pp.37-41
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• 2012

현재 복어독의 표준 시험법은 다른 나라들과 마찬가지로 마우스를 이용한 동물시험법으로 명시되어 있다. 그러나, 살아있는 동물에게 고통을 주는 동물실험의 규제 확대로 인해 기기분석 시험법으로의 개선이 요구되고 있다. 또한, 동물시험법의 감도나 정밀성 및 정확성의 한계로 최근에 동물시험법을 대체할 수 있는 시험법에 대한 연구가 활발히 진행되고 있다. 본 연구에서 LC/MS/MS 시험법은 시료에서 테트로도톡신을 추출한 후 SPE(Solid phase extraction) 정제칼럼을 이용하여 정제하고 양이온 모드에서 MRM(multiple reaction monitoring)방법으로 분석하는 시험법으로서 밸리데이션 결과 검출한계(LOD)는 부위에 따라 $0.03{\sim}0.08{\mu}g/g$이었고, 정량한계(LOQ)는 $0.10{\sim}0.25{\mu}g/g$이었다. 검량선의 상관계수($r^2$)는 0.9986~0.9997이고, 회수율은 80.9%~103.0%이었으며 상대표준편차(RSD)는 4.3%~13.0%로서 적합한 시험법임을 확인하였다. 이 시험법을 이용하여 복어 검체의 부위별로 분석을 실시하였으며, 동물시험법의 시험결과와의 상관관계를 분석한 결과, 상관계수는 0.95이상의 상관성을 확인하였다.