• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.285-291
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• 2005

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is the viral RNA-dependent RNA polymerase (RdRp), which is the essential catalytic enzyme for the viral replication and is an appealing target for the development of new therapeutic agents against HCV infection. A small amount of serum from a single patient with hepatitis C was used to get the genome of a Korean HCV isolate. Sequence analysis of NS5B 1701 nucleotides showed the genotype of a Korean isolate to be subtype 1b. The soluble recombinant HCV NS5B polymerase lacking the C-terminal 24 amino acids was expressed and purified to homogeneity. With the highly purified NS5B protein, we established in vitro systems for RdRp activity to identify potential polymerase inhibitors. The rhodanine family compounds were found to be potent and specific inhibitors of NS5B from high throughput screening (HTS) assay utilizing the scintillation proximity assay (SPA) system. The binding mode of an inhibitor was analyzed by measuring various kinetic parameters. Lineweaver-Burk plots of the inhibitor suggested it binds not to the active site of NS5B polymerase, but to an allosteric site of the enzyme. The activity of NS5B in in vitro polymerase reactions with homopolymeric RNA requires interaction with multiple substrates that include a template/primer and ribonucleotide triphosphate. Steady-state kinetic parameter, such as Km, was determined for the ribonucleotide triphosphate. One of compounds found interacts directly with the viral polymerase and inhibits RNA synthesis in a manner noncompetitively with respect to UTP. Furthermore, we also investigated the ability of the compound to inhibit NS5B-directed viral RNA replication using the Huh7 cell-based HCV replicon system. The investigation is potentially very useful for the utility of such compounds as anti-hepatitic agents.

• 공업화학
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• 제5권3호
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• pp.501-508
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• 1994

방출조절성 약제를 개발하기 위한 방법으로 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl)quitoline-3-carboxylic acid의 $C_3$ 위치를 Vilsmeier reagent로 chlorination하여 이를 dextran과 반응시켜 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazlnyl) quinoline-3-carboxylic acid-dextran 중합체약을 합성하였다. 중합체약에 대한 최소발육저지농도(MICs)로서 Gram 양성세균 Bacillus subtillis ATCC 6633, Staphyloccus aureus ATCC 25923, Mycrobacterium phlei IFO 3158 및 Salmonella typhimurium KCTC 1925에 대해서 각각 $5{\mu}g/ml$의 농도로 균의 발육을 억제하였다. Micrococcus luteus ATCC 9341에 대해서는 $80{\mu}g/ml$로 약한 활성을 보였을 뿐, Gram 양성세균들에 대하여 전반적으로 강한 저항성을 보여주었다. Gram 음성세균인 Escherichia coli KCTC 1039, Escherichia coli ESS, Klebsiella puenmouiae KCTC 1560 및 Psendomonas aeruginosa IFO 13130 균주들에 대해서도 각각 $5{\mu}g/ml$로 대조물질과 유사한 항균성을 보여주었다. 한편, quinolone계 항균제가 진균류에 대하여 감수성을 보이지 않는 것처럼 중합체약도 진균인 Candida albicans ATCC 10231에 대해서는 감수성을 보여주지 않았다.

• 한국축산식품학회지
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• 제35권1호
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• pp.121-129
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• 2015

${\beta}$-agonists are anabolic compounds that promote fat loss and muscle gain, and their administration to livestock may provide economic benefits by increasing growth rate and feed efficiency. For these reasons, ${\beta}$-agonists are also commonly added to livestock feed as growth promoters. This can introduce a significant risk of secondary human poisoning through intake of contaminated meat. A new method for the simultaneous determination of three ${\beta}$-agonists (clenbuterol, ractopamine, and zilpaterol) was developed in this study and applied to various meat samples. The limits of quantification, derived through a validation test following Codex guidelines, were $0.2{\mu}g/kg$ for clenbuterol and zilpaterol, and $0.4{\mu}g/kg$ for ractopamine. The average recoveries for clenbuterol, ractopamine, and zilpaterol ranged from 109.1% to 118.3%, 95.3% to 109.0%, and 94.1% to 120.0%, respectively. The recovery and coefficient of variation (CV) values fell within the acceptable range according to the Codex guidelines. This method reduced the analysis time without decreasing detection efficiency by modifying the pretreatment steps. This method could be utilized to manage the safety of imported meat products from countries where zilpaterol use is still permitted, thereby improving public health and preventing ${\beta}$-agonist poisoning due to secondary contamination.

• Archives of Pharmacal Research
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• 제27권5호
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• pp.576-580
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• 2004

Primaquine is used for relapses caused by vivax malaria hypnozoites. No studies on the pharmacokinetics of primaquine (PMQ) has been reported in Korean patients. In our study, thirty vivax malaria patients were given 15 mg primaquine daily for 14 days after 3 days of chloroquine treatment. Plasma samples were taken at intervals after each daily dose of PMQ for 3 days. Plasma concentrations of PMQ and carboxyprimaquine (CPMQ), the major metabolite of primaquine, were measured by HPLC. The PMQ concentrations reached a maximum of 0.28$\pm$0.18 $\mu\textrm{g}$/mL at 1.5 h after the first dose. The maximum concentration of CPMQ was 0.32$\pm$0.13 $\mu\textrm{g}$/mL at 4 h. Higher drug concentrations with repeated dosing were observed for CPMQ, but not for the parent drug, PMQ. The elimination half-life was 3.76$\pm$1.8 hand 15.7$\pm$12.2 h, for PMQ and CPMQ, respectively. Large variation in the plasma concentrations of both drugs was observed. Overall, PMQ is absorbed and metabolized rapidly after oral administration. It was noted that the mean peak plasma concentration of PMQ was significantly higher and that of CPMQ was lower in our patients compared to other studies. This suggests a potential difference of inter-ethnic groups, which warrants further investigations.

• 의료법학
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• 제21권1호
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• pp.223-259
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• 2020

COVID-19가 순식간에 세계적으로 퍼져나가면서 이 바이러스에 대한 치료제 및 백신에 대한 연구 개발 이슈가 뜨겁다. 그 중에서도 렘데시비르(Remdesivir)가 가장 먼저 눈에 띄는 치료효과를 나타내며 본격적인 임상시험에 돌입하였고, 각 국가들은 긴급 승인을 통해 해당 의약품의 사용을 허가하고 있다. 그런데 렘데시비르의 개발사인 주식회사 길리어드는 렘데시비르를 희귀의약품으로 품목허가 신청하여 시민단체들로부터 많은 질타를 받았다. 그 이유는 희귀의약품으로 신약이 품목허가를 취득하는 경우 7년의 독점적 지위를 부여받을 수 있기 때문이다. 희귀의약품에게 장기간 동안 독점적 지위를 부여하는 것은 희귀질환으로 고생하는 환자들에게 치료기회를 부여하기 위해 제약회사에게 개발 동기를 부여하는 정책적 취지로부터 나온 것으로, 감염병 치료제에 적용하기에는 적절하지 않았기 때문이다. 본 논문은 이러한 정책적 의도를 바탕으로 의약품에 독점적 지위를 부여하고 있는 법령에 대하여 미국, 유럽, 일본을 상대로 비교법적 고찰을 통해 국내 제도의 문제점 및 개선 방향에 대해 살펴보는 내용을 담고 있다. 국내 제도는 독점적 지위 부여 방식에 있어 법령에 명시적인 조항을 두고 있지 않고, 재심사제도를 활용하여 우회적으로 독점적 지위를 부여하고 있다는 근본적인 문제를 갖고 있다. 이와 더불어 희귀의약품의 경우 「희귀질환관리법」과 「의약품의 품목허가·신고 심사 규정」에서 중복적으로 재심사기간을 규정하고 있다는 점, 상대적으로 독점기간을 길게 부여하고 있음에도 불구하고 사정변경 발생 시 독점적 지위를 회수할 수 있는 견제 조항이 존재하지 않는다는 점 등이 보완되어야 할 부분으로 보인다. 생물의약품의 경우에는 국내에는 우회적으로라도 의약품의 독점적 지위를 부여할 수 있는 규정이 존재하지 않는다. 생물의약품의 경우 특허를 받기 어렵다는 점에서, 독점권을 부여하는 것이 의약품 개발을 유도하는 큰 동기가 될 수 있음에도 이러한 조항이 없다는 점은 국내 법제의 아쉬운 점이라 볼 수 있다. 미국의 경우 최초의 동등생물의약품에도 1년의 독점기간을 부여한다는 점에 비추어 볼 때, 국내 법제는 생물의약품에 독점적 지위를 부여하는 것에 대하여 상당히 엄격하게 제한하고 있다고 해석된다. 이는 추후 국내 제약사의 생물의약품 개발 의지를 저하시킬 수 있다는 점에서, 또한 국제 규제의 조화를 맞출 필요가 있다는 점에서 국내 제도의 개선의 필요성이 인정된다 할 것이다. COVID-19의 발현을 기회로 삼아, 의약품에 독점권을 부여하고 있는 국내 제도가 가지고 있는 문제점에 대하여 다시 한 번 살펴보고, 통일된 법적 근거를 마련할 수 있도록 관련 법제에 대한 전반적인 개정이 이루어 질 것을 기대해보는 바이다.

• Weed & Turfgrass Science
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• 제5권3호
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• pp.136-143
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• 2016

본 연구에서는 캐슈넛 오일의 살조활성 특징을 파악하고, 유해조류를 보다 효과적으로 제어할 수 있는 혼합처리제를 개발하기 위하여 실시하였다. 공시된 시험 추출물중 anacardic acid 함량이 상대적으로 높은 Ana-A가 남조류 M. aeruginosa에 대한 살조활성이 가장 높았다. Ana-A는 전체적으로 녹조류보다는 남조류에 대해 더 높은 살조활성을 가지면서 폭넓은 살조활성스펙트럼을 보였다. Ana-A에 대한 남조류 종간 반응에 있어서는 Oscillatoria tenuis ($IC_{50}=0.19{\mu}g\;mL^{-1}$)가 가장 민감하였고, 녹조류 중에서는 Chlorella vulgaris가 상대적으로 가장 민감한 반응을 나타내었다($IC_{50}=4.54{\mu}g\;mL^{-1}$). Ana-A와의 혼합처리를 통해 효능이 상승되는 화합물을 탐색한 결과, MSB와 menadione은 매우 강한 상승작용을, citric acid는 약간의 상승작용을, chrysophanol, copper sulfate, quinoclamine 등은 상가적 작용의 활성을 나타내었다. 종합적으로 볼 때, anacardic acid 고함유 캐슈넛 오일은 처리량의 최적화와 상승작용을 가지는 MSB 또는 menadione과 같은 화합물과의 혼합처리를 통해 M. aeruginosa 및 O. tenuis가 발생하는 현장의 선택적 제어를 위해 환경 친화적인 살조제로서 유용하게 활용될 수 있을 것 같았다.

• 한국임상약학회지
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• 제20권3호
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• pp.221-228
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• 2010

In 2009, American Journal of Health-System Pharmacy (AJHP) recommended that targeting vancomycin trough concentrations of 10 mg/L or more because of therapeutic failure and potential risk of developing vancomycin resistance. Therefore, new dosage guidelines that could achieve to these higher target were needed. The aims of this study were to develop dosage guidelines targeting new vancomycin trough concentration and to evaluate the performance of these new guidelines. All data analysis were performed using NONMEM(R). Population pharmacokinetic model was first developed from vancomycin dosage and concentration data collected retrospectively during routine therapeutic drug monitoring in 441 patients, then new vancomycin dosage guidelines were developed by using the model to predict vancomycin trough and peak concentrations in a simulated dataset. The estimates, such as, vancomycin concentration trough level, time to achieve target level, mean error were performed to evaluate and compare difference between conventional dosage and new dosage guidelines. The proposed dosage guidelines were predicted to achieve 43.5% of vancomycin trough level within 10~20 mg/L, which is significantly higher than current guidelines (26.3%). Time to achieve target trough level was 19.4 hours in new guidelines comparing to 93.1 hours in the conventional dosage. Thus, new vancomycin dosage guidelines have been developed to achieve new target trough concentrations earlier and more consistently than conventional guidelines.

• Tuberculosis and Respiratory Diseases
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• 제73권1호
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• pp.1-10
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• 2012

Care of patients with sepsis has improved over the last decade. However, in the recent two years, there was no significant progress in the development of a new drug for critically ill patients. In January 2011, it was announced that the worldwide phase 3 randomized trial of a novel anti-Toll-like receptor-4 compound, eritoran tetrasodium, had failed to demonstrate an improvement in the mortality of patients with severe sepsis. In October 2011, Xigris (drotrecogin alfa, a recombinant activated protein C) was withdrawn from the market following the failure of its worldwide trial that had attempted to demonstrate improved outcome. These announcements were disappointing. The recent failure of 2 promising drugs to further reduce mortality suggests that new approaches are needed. A study was published showing that sepsis can be associated to a state of immunosuppression and loss of immune function in human. However, the timing, incidence, and nature of the immunosuppression remain poorly characterized, especially in humans. This emphasizes the need for a better understanding of sepsis as well as new therapeutic strategies. Many clinical experiences of the extracorporeal membrane oxygenator (ECMO) treatment for adult acute respiratory distress syndrome (ARDS) patients, which is caused by the H1N1 influenza A virus, were reported. The use of ECMO in severe respiratory failure, particularly in the treatment of adult ARDS, is occurring more commonly.

• 생약학회지
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• 제42권4호
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• pp.354-360
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• 2011

In order to screen new allogeneic mixed lymphocyte culture (allo-MLR) inhibitor which is expected to be immunomodulating drug lead, we have investigated allo-MLR inhibitory activity on the marine-derived symbiotic microorganisms (1,895 strains) from the marine algae. The potent inhibitory activities (over 45% inhibition of proliferation at 10 and 2 ${\mu}g/ml$) without cytotoxicity were observed in the extracts of 46 strains. While, the significant stimulating activities (over 100% proliferation at 10 and 2 ${\mu}g/ml$) without cytotoxicity were observed in the extracts of 5 strains. In the second assay using 46 bioactive strains, 14 strains exhibited again significant allo-MLR inhibitory activity. Finally, 11 strains among the 14 strains inhibited proliferation and IFN-${\gamma}$ production of CD4+ T cells during the stimulation with specific antigen in the third assay. On the basis of above results, the marine algae is nice source for isolation of immunomodulating microorganism, and the marine algae-associated microorganism is also nice target for development of the new immunomodulating drug lead.

• 약학회지
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• 제47권4호
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• pp.234-238
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• 2003

Linarin is a main compound from Chrysanthemum zawadskii var, latilobum. However, the biological mechanisms of these activities are unclear. Because of this wide diversity of effects, it is believed that they may be exerted through pluripotent effectors of linarin. In our previous screening study, the effects of linarin on the mouse macrophages cell line, RAW 264.7 cells, were investigated. It was found that linarin could stimulate macrophages activation by the production of tumor necrosis factor (TNF). The linarin (6.25∼12.5 $\mu\textrm{g}$/mι) inhibited the production of NO in LPS-activated RAW 264.7 cells and linarin became an useful candidates for the development of new drug to treat endotoxemia and inflammation accompanied by the overproduction of NO. However, linarin-treated total lymphocyte showed cytotoxicity in a dose dependent manner between 20 $\mu\textrm{g}$/mι and 40 $\mu\textrm{g}$/mι. In this study, linarin derivative (acetylated linarin) was synthesized in order to obtain less-cytotoxicity of linarin and evaluated for their in vitro cytotoxic activity aganist mouse total lymphocyte. There was no cytotoxic activity in a dose dependent manner (20∼40 $\mu\textrm{g}$/mι) of acetylated linarin whereas linarin showed. The production of NO, however, was not the case by this modified linarin. The cell morphological change was not significantly changed in response to acetylated linarin alone and these effects were potentiated by the addition of LPS. These results suggest that acetylated linarin may be developed to be a promising new drug candidate without cytotoxicity on the basis of its activity of macrophage activation.