• 공업화학
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• 제21권6호
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• pp.603-609
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• 2010

수첨 인지질의 하나인 distearoylphosphatidylcholin (DSPC)을 주로 하면서 피부보습에 도움을 주는 용매인 glycerin (GLY)에 의해 팽윤되어 형성된 라멜라 액정상 구조에 피부장벽을 구성하는 지질 중 하나로서 ceramide 3 (CER3)이 함께 배향될 때 나타나는 함량 의존적 거동을 DSC, XRDs, PM 및 Cryo-SEM에 의해 고찰하였다. CER3은 매우 결정성이 높지만, DSPC와의 구조적인 유사성을 가지고 있어 DSPC 20.0 wt% 함량대비 7.0 wt%까지는 탈리 없이 배향되지만, 그 이상을 배향시킬 경우 CER3이 액정 내에서 탈리되어 자체로 GLY에 팽윤되어 또 다른 액정상을 형성하는 것을 XRD의 특성피크 발현과 DSC의 공융점 거동을 통해 확인할 수 있었다. 또한 CER3이 액정 내에 배향되면서 DSPC만으로 이루어진 액정에서 보이는 SPP패턴뿐만 아니라, 피부 각질층에서 주로 나타나는 LPP패턴도 SAXD분석을 통해 확인되어, CER3을 적용시 인간피부와 보다 흡사한 액정구조를 형성함을 확인하였다. Cryo-SEM을 이용하여 DSPC만으로 이루어진 액정과 여기에 CER3이 도입된 액정을 비교한 결과, CER3은 액정의 구조를 보다 두텁고, 견고하게 함을 알 수 있었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.46-54
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• 2015

Toxicity and uptake of 2,4,6-trinitrotoluene (TNT) in three different soils (OECD soil, natural soil and loess) to earthworm (Eisenia fetida) were investigated at several different spiked concentrations of TNT (0 to 200 mg/kg for OECD and natural soils, and 0 to 35 mg/kg for loess) and for different exposure periods (7, 14, 21, and 28 d). The LC₅₀ values for 7 d exposure were 160.1, 159.4, and 28.81 mg/kg for OECD soil, natural soil, and loess, respectively. The LC₅₀ values for 14, 21, and 28 d exposure were almost the same as those for 7 d exposure, showing that 7 d exposure time was enough to decide the toxicity (LC₅₀) of TNT to Eisenia fetida, because the highest concentration of TNT in earthworm body was observed within around 5 d. The LC₅₀ and uptake of TNT in loess were higher than those in OECD and natural soil. The uptake of TNT to the earthworm were correlated well with the initial concentration of TNT in the soil and TNT porewater concentration (R²> 0.9 in OECD, natural, and loess). The concentration of TNT in earthworm body decreased after 5 d, possibly caused by natural degradation of TNT by soil bacteria as well as earthworm.

• Journal of Pharmaceutical Investigation
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• 제37권3호
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• pp.179-186
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• 2007

A simple, sensitive and selective liquid chromatographic/tandem mass spectrometric method (LC-MS/MS) was developed and validated for doxifluridine and 5-fluorouracil (5-FU) quantification in dog heparinized plasma. Sample preparation was based on liquid-liquid extraction using a mixture of isopropanol/ethyl acetate (1/9 v/v) to extract doxifluridine, 5-FU and 5-chlorouracil (5-CU, an internal standard) from plasma. Chromatography was performed on a C-18 analytical column and the retention times were 2.7, 1.5 and 1.7 min for doxifluridine, 5-FU and 5-CU, respectively with shorter analysis time within 5 min than previously reported methods. The ionization was optimized using ESI negative mode and selectivity was achieved by tandem mass spectrometric analysis by multiple reaction monitoring (MRM) using the transformations of m/z 244.8>107.6, 129.0>42.0 and 144.9>42.1 for doxifluridine, 5-FU and 5-CU, respectively. The achieved low limit of quantification was 20.0 ng/mL and the assay exhibited linear range of 20-2000 ng/mL ($R^2>0.99957$ for doxifluridine and $R^2>0.99857$ for 5-FU), using $100{\mu}L$ of plasma. Accuracy and precision of quality control samples for both doxifluridine and 5-FU met KFDA and FDA Guidance criteria of 15% for accuracy with coefficients of variation less than 15%. This method demonstrated adequate sensitivity, specificity, accuracy, precision and stability to support the simultaneous analysis of doxifluridine and 5-FU in dog plasma samples in pharmacokinetic and bioequivalence studies.

• The Korean Journal of Physiology and Pharmacology
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• 제20권3호
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• pp.237-243
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• 2016

Oleanolic acid (OA) has a wide variety of bioactivities such as hepatoprotective, anti-inflammatory and anti-cancer activity and is used for medicinal purposes in many Asian countries. In the present study, the effect of OA on induction of autophagy in human hepatocellular carcinoma HepG2 and SMC7721 cells and the related mechanisms were investigated. MTT assay showed that OA significantly inhibited HepG2 and SMC7721 cells growth. OA treatment enhanced formation of autophagic vacuoles as revealed by monodansylcadaverine (MDC) staining. At the same time, increasing punctuate distribution of microtubule-associated protein 1 light chain 3 (LC3) and an increasing ratio of LC3-II to LC3-I were also triggered by OA incubation. In addition, OA-induced cell death was significantly inhibited by autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) pretreatment. And we found out that OA can suppress the PI3K/Akt1/mTOR signaling pathway. Furthermore, our data suggested that OA-triggered autophagy was ROS-dependent as demonstrated by elevated cellular ROS levels by OA treatment. When ROS was cleared by N-acetylcysteine (NAC), OA-induced LC3-II convertsion and cell death were all reversed. Taken together, our results suggest that OA exerts anticancer effect via autophagic cell death in hepatocellular carcinoma.

• 한국수산과학회지
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• 제36권3호
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• pp.225-229
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• 2003

Plant ash and soil drainage, derived by frequent mountain fires during winter, might cause biological contamination to seaweeds at seashore and river mouse area. To thalli of Ulva pertusa, maximum non-lethal concentration(MNLC), lethal concentration 50 $(LC_{50})$ and minimum lethal concentration (MLC) of pine needle ash were shown as 60, 350 and 550 mg/mL, respectively. The yellow loess and granite sand did not damage at concentrations of 20 and 200 mg/mL, respectively To thalli of Porphyra yezoensis, the MNLC, LC5O, MLC of pine needle ash were shown as 0.08, 0.4 and 1.0 mg/mL, respectively. Effects of yellow loess and granite sand were approximately 1/2 and 1/10 of the ash. To thalli of Undaria pinnatifida, the pine needle ash, yellow loess and granite sand did not damage at the concentration range of 20 to 40 mg/mL. Change of pigments $(chlorophyll\;\alpha,\;lutein,\;\beta-carotene,\;phycoerthrin)$ was also determined at the MNLC, $LC-{50}$ and MLC of pine needle ash. Among three seaweeds tested, P. yezoensis produced the most 2.7-fold of lutein and 2.3-fold of $\beta-carotene$ at $LC-{50}$ of the ash. Thus the P. yezoensis, appeared as a sensitive indicator, could be used as one of test organisms for determination of the biological effect of pollutants contaminated in marine environment.

• 생약학회지
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• 제48권4호
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• pp.320-328
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• 2017

Yongdamsagan-tang has been used to treat the urinary disorders, acute- and chronic-urethritis, and cystitis in Korea. In this study, an ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS) method was established for simultaneous analysis of the 20 bioactive marker compounds, geniposidic acid, chlorogenic acid, geniposide, liquiritin apioside, acteoside, calceolarioside B, liquiritin, nodakenin, baicalin, liquiritigenin, wogonoside, baicalein, glycyrrhizin, wogonin, glycyrrhizin, wogonin, saikosaponin A, decursin, decursinol angelate, alisol B, alisol B acetate, and pachymic acid in traditional herbal formula, Yongdamsagan-tang. Chromatographic separations of all marker compounds were conducted using a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) at $45^{\circ}C$ using a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile with gradient elution. The MS analysis was performed using a Waters ACQUITY TQD LC-MS/MS coupled with an electrospray ionization source in the positive and negative modes. The flow rate was 0.3 mL/min and injection volume was $2.0{\mu}L$. The correlation coefficient of 20 marker compounds in the test ranges was 0.9943-1.0000. The limits of detection and quantification values of the all marker components were 0.11-6.66 and 0.34-19.99 ng/mL, respectively. As a result of the analysis using the optimized LC-ESI-MS/MS method, three compounds, geniposidic acid (from Plantaginis Semen), alisol B (from Alismatis Rhizoma), and pachymic acid (from Poria Sclerotium), were not detected in this sample. While the amounts of the 17 compounds except for the geniposidic acid, alisol B, and pachymic acid were $0.04-548.13{\mu}g/g$ in Yongdamsagan-tang sample. Among these compounds, baicalin, bioactive marker compound of Scutellariae Radix, was detected at the highest amount as a $548.13{\mu}g/g$.

• 분석과학
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• 제22권4호
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• pp.319-325
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• 2009

벌꿀 중에 잔류하는 아미노그라이코사이드 항생제인 네오마이신을 효과적으로 분석하는 방법을 개발하고 방법에 대한 유효성 검증을 수행하였다. 0.1M 염산을 사용하여 벌꿀의 pH를 2로 조절한 후 고체상 추출(SPE) 고체상인 양이온교환 카트리지에 적재한 후 염기성 메탄올로 용리하였다. 용리된 추출물은 이온쌍 시약을 사용한 이온쌍 크로마토그래피법으로 분리한 후 LC/(+)ESI-MS/MS의 MRM 방법으로 분석하였다. 정량분석을 위해서 spike 한 $5.0{\sim}250{\mu}g/kg$ 농도 범위에서 검정곡선은 좋은 직선성 ($r^2$ > 0.9951)을 나타내었다. 분석방법의 상대표준편차는 11.5~18.7%이었고 정확도는 bias로 10.9~20.9%이었다. 확립된 분석방법은 벌꿀 중에서 네오마이신의 분석방법으로 유용하게 사용될 수 있을 것이다.

• 분석과학
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• 제20권2호
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• pp.115-123
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• 2007

헤테로싸이클릭 아민류(heterocyclic amines, HAs)는 소고기, 돼지고기, 닭고기 그리고 생선과 같은 근육질의 육류를 조리 할 때 생겨나는 돌연변이원성/발암성 화학물질로 잘 알려져 있다. 식품으로부터 HAs의 분석에 있어 가장 큰 어려움은 HAs가 식품 중에 극히 미량(수 ng/g)으로 존재한다는 것과 많은 방해물질이 존재한다는 것이다. 식품으로부터 HAs를 추출하고 정제하기 위해 고체-상 추출(solid-phase extraction, SPE)이 많이 사용되고 있다. HAs 분석을 위해 여러 단계의 SPE 과정을 수행하였다. HAs의 회수율은 표준물질이 녹여져 있는 메탄올 수용액과 조리되지 않은 돼지고기에 표준용액을 스파이크하여 서로를 비교하여 얻었다. 회수율은 25.0 ng/g에서 25.3~93.0%의 값을 얻을 수 있었다. 확립된 감도 좋고 재현성있는 시료전처리방법을 통해서 ${\mu}$-LC/ESI-MS에 주입함으로써 조리된 육류로부터 HAs를 분석하는데 응용될 수 있을 것이다. 다른 방법으로는 freezing filtration 방법으로써 보다 좋은 추출 효율과 재현성을 나타내었다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제1권1호
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• pp.61-67
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• 1997

The effects of Insect growth regulator Dimilin which interfere with the synthesis of chitin in the cuticle of insect larvae were investigated at various concentrations using the copepod larvae of Tigriopus japonicus Mori. The larvae were cultured at control, 1, 5, 10, 20, 50, and 100 ppb Dimilin solutions and three replicate experiment were carried out to give correct analysis. Lethal effects of Dimilin on larvae of T. japonicus occurred above 1 ppb Dimilin solution after 8 days. $LC_{50}$ of larvae was 50 ppb Dimilin on the 4th day. Lethal effects of Dimilin on adults or T. japonicus occurred above 20 ppb Dimilin solution after 13 days. $LC_{50}$ of adults was 50 ppb Dimilin on the 12 days. Egg viability has little relation to Dimilin solution concentrations.

• Journal of Dairy Science and Biotechnology
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• 제33권3호
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• pp.215-221
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• 2015

면역 활성능이 높은 균주로 선발된 Streptococcus macedonicus LC743를 이용하여 모짜렐라 치즈를 제조하기 위해 배양온도별($32^{\circ}C$, $35^{\circ}C$), 균주의 접종량 별(1.0%, 2.0%)로 모짜렐라 치즈를 제조하여 일반성분, 균수, 총고형분 및 수율 및 면역 활성을 측정하여 최적조건을 설정하였다. S. macedonicus LC743 균주를 이용하여 치즈 제조 시 2.0% 접종하여 $32^{\circ}C$에서 배양할 경우 가장 제조 시간이 단축되었고, 가공적성 및 면역활성이 우수하였다.