• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.251.2-251.2
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• 2002

2-Methylaminoethyl- 4,4' -dimethoxy- 5, 5',6,6' -dimethylenedioxybiphenyl- 2' -carboxy- 2-carboxylate (DDB-S) is a synthetic compound derived from DDB. which is protects liver against carbon tetrachloride-, D-galactosamine-, thioacetamine-, and prednisolone- induced hepatic injury in experimental animals. We assessed the use of liquid chromatography/electrospray iontrap tandem mass spectrometry (LC/MS/MS) method to identify and quantify in vivo metabolites and to measure excretion. (omitted)

• 대한화학회지
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• 제59권3호
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• pp.225-232
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• 2015

하천수 중에 7가지의 농약류(2,4-dichlorophenoxyacetic acid, 메소밀, 알디캅, MCPA, molinate, 카바릴, 카보퓨란)와 2가지의 합성원료(quinoline, 비스페놀-A)를 액체크로마토그래피 전자분무 이온화 질량분석법(liquid chromatography-electrospray ionization-tandem mass spectrometry, LC-ESI-MS/MS)을 사용하여 분석하였다. 분석물질들은 고체상 추출법(solid-phase extraction, SPE)을 사용하여 추출하였다. 용리액은 질소가스로 농축하였다. 잔여물에 30% 메탄올 수용액 100 μL를 재 용해시켜 0.2 μm PTFE 실린지 필터로 거른 후 그 일부를 LC-ESI-MS/MS에 직접 주입하여 분석하였다. 확립된 조건에서 검정곡선은 0.997 이상의 상관계수를 갖는 직선성을 보였다. 정량한계는 0.002~0.011 μg/L 이었고, 정밀도는 16.4% 이하였다. 또한 정확도는 84~107%의 범위를 보였고, 회수율은 56.2~98.6% 값을 나타내었다. 본 연구에서 개발한 분석법을 실제 하천수 분석에 적용하였다.

• Bulletin of the Korean Chemical Society
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• 제26권5호
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• pp.729-734
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• 2005

A sensitive and selective method for quantitation of sofalcone and its active metabolite in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS). Plasma samples were transferred into 96-well plate using an automated sample handling system and spiked with 10 $\mu$L of 2 $\mu$g/mL $d_3$-sofalcone and $d_3$-sofalcone metabolite solutions (internal standard), respectively. After adding 0.5 mL of acetonitrile to the 96-well plate, the plasma samples were then vortexed for 30 sec. After centrifugation, the supernatant was transferred into another 96-well plate and completely evaporated at 40 ${^{\circ}C}$ under a stream of nitrogen. Dry residues were reconstituted with mobile phase and were injected into a $C_{18}$ reversed-phase column. The limit of quantitation of sofalcone and its metabolite was 2 ng/mL, using a sample volume of 0.2 mL for analysis. The reproducibility of the method was evaluated by analyzing 10 replicates over the concentration range of 2 ng/mL to 1000 ng/mL. The validation experiments of the method have shown that the assay has good precision and accuracy. Sofalcone and its metabolite produced a protonated precursor ion ([M+H]$^+$) of m/z 451 and 453, and a corresponding product ion of m/z 315 and 317, respectively. Internal standard ($d_3$-sofalcone and $d_3$-sofalcone metabolite) produced a protonated precursor ion ([M+H]$^+$) of m/z 454 and 456 and a corresponding product ion of m/z 315 and 317, respectively. The method has been successfully applied to a pharmacokinetic study of sofalcone and its active metabolite in human plasma.

• 한국축산식품학회지
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• 제35권6호
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• pp.765-771
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• 2015

The development of a sample preparation method and optimization of the analytical instrumentation conditions were performed for the determination of the vitamin B₁₂ content in emulsified baby foods sold on the Korea market. After removal of the milk protein and fats by chloroform extraction and centrifugation, the vitamin B₁₂ was water extracted from the sample. Following filtration of the solution through a nylon filter, the water-soluble extract was purified by solid-phase extraction using a Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). The solution eluted from the cartridge was dried under a stream of nitrogen gas and reconstituted with 1 mL of water. The sample solution was injected into an LC-MS/MS system after optimizing the mobile phase for vitamin B₁₂ detection. The calibration curve showed good linearity with the coefficient of correlation (r²) value of 0.9999. The limit of detection was 0.03 µg/L and the limit of quantitation was 0.1 µg/L. The method of detection limit was 0.02 µg/kg. The vitamin B₁₂ recovery from a spiking test was 99.62% for infant formula and 99.46% for cereal-based baby food. The sample preparation method developed in this study would be appropriate for the rapid determination of the vitamin B₁₂ content in infant formula and baby foods with emulsified milk characteristics. The ability to obtain stable results more quickly and efficiently would also allow governments to exercise a more extensive quality control inspection and monitoring of products expected to contain vitamin B₁₂. This method could be implemented in laboratories that require time and labor saving.

• 한국식품위생안전성학회지
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• 제32권2호
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• pp.89-95
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• 2017

에너지 음료는 카페인을 주성분으로 타우린, 비타민 같은 다른 energy-enhancing 성분을 함유하고 있다. 미국과 유럽에서는 글루쿠로노락톤이 에너지 음료에 첨가될수 있으나, 국내에서 의약품으로는 허가되어 있다. 따라서 식품 첨가물로는 그 사용이 금지 되어 있어, 지속적으로 수입 및 유통 음료에서 시험검사를 하여 규제하고 있다. 현재 분석법으로 사용하는 LC-PDA 법은 복잡한 유도체화 과정을 거치고, 음료 중에 당류들이 위양성 결과를 나타내기도 한다. 이런 기존 방법의 단점을 개선하기 위해 HILIC-ESI-MS/MS(hydrophilic interaction liquid chromatography coupled to electrospray ionization tandem mass spectrometry)를 이용한 분석법을 개발하고, 선택성, 직선성, 검출한계, 정량한계, 정밀도, 정확성, 재현성에 대하여 분석법 유효성 검증을 수행했고, AOAC, EURACHEM 가이드라인에 부합되는 결과를 얻었다.

• Translational and Clinical Pharmacology
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• 제25권2호
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• pp.67-73
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• 2017

Glimepiride, a third generation sulfonylurea, is an antihyperglycemic agent widely used to treat type 2 diabetes mellitus. In this study, an untargeted urinary metabolomic analysis was performed to identify endogenous metabolites affected by glimepiride administration. Urine samples of twelve healthy male volunteers were collected before and after administration of 2 mg glimepiride. These samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and then subjected to multivariate data analysis including principal component analysis and orthogonal partial least squares discriminant analysis. Through this metabolomic profiling, we identified several endogenous metabolites such as adenosine 3', 5'-cyclic monophosphate (cAMP), quercetin, tyramine, and urocanic acid, which exhibit significant metabolomic changes between pre- and posturine samples. Among these, cAMP, which is known to be related to insulin secretion, was the most significantly altered metabolite following glimepiride administration. In addition, the pathway analysis showed that purine, tyrosine, and histidine metabolism was affected by pharmacological responses to glimepiride. Together, the results suggest that the pharmacometabolomic approach, based on LC-MS/MS, is useful in understanding the alterations in biochemical pathways associated with glimepiride action.

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.291-294
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• 2006

A highly sensitive high-performance liquid chromatographic-tandem mass spectrometric method (HPLC-MSMS) has been developed to quantify itraconazole in human plasma for the purpose of pharmacokinetic studies. Sample preparation was carried out by liquid-liquid extraction using loratadine as an internal standard. Chromatographic separation used a YMC $C_{18}$ column, giving an extremely fast total run time of 3 min. The method was validated and used for the bioequivalence study of itraconazole tablets in healthy male volunteers (n = 31). The lower limit of detection proved to be 0.2 ng /mL for itraconazole.

• 분석과학
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• 제30권3호
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• pp.122-129
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• 2017

Methamphetamine addiction is a critical issue due to the lack of effective pharmacotherapy and high potential for relapse. Nevertheless, there are no distinct biomarkers for diagnosis or prognosis for methamphetamine addiction. In the present study, a rat model for methamphetamine self-administration was established and alteration of urinary metabolites by methamphetamine addiction was investigated by the targeted metabolite analysis using mass spectrometry. Rat urine samples were collected at three time points (before and after addiction and after extinction) from the methamphetamine-addicted group as well as the age-matched control group. The collected samples were prepared using AbsoluteIDQ p180 kit and analyzed using flow injection analysis (FIA) - or high performance liquid chromatography (HPLC) - tandem mass spectrometry (MS/MS). The levels of lysine, acetylornithine and methioninesulfoxide were distinctively altered depending on the status of metheamphetamine addiction or extinction. In particular, the level of acetylornithine was reversely changed from addiction to extinction, for which further studies could be useful for biomarker discovery or mechanistic studies for methamphetamine addiction.

• Mass Spectrometry Letters
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• 제6권4호
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• pp.116-119
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• 2015

Globotriaosylsphingosine (lyso-Gb3) is considered as one of the biological marker for Fabry disease. To date, a reliable biomarker that reflects disease severity and progression has not been discovered to guide the management of Fabry disease. A new method included a simple protein precipitation with acetonitrile in 100 μL of plasma following analyte separation on an Phenomenex Kintex- C18 column using a gradient elution (0.1% formic acid in 5-90% acetonitrile). Total run time was within 12 min including sample preparation and MS/MS analysis. The limit of detection and limit of quantitation were 1 ng/mL and 2 ng/mL, respectively. The calibration curve was linear over the concentration range of 2.0-200.0 ng/mL (r² = 0.9999). Inter-day accuracy and precision at 7 level were 93.4-100.7% with RSD of 0.55-5.97%. Absolute recovery was 97.6-98.6%. The method was applied to human and mice plasma, proved the suitability for quantification of lyso-Gb3 for screening, diagnosis and therapeutic monitoring of Fabry disease patients.

• Mass Spectrometry Letters
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• 제3권4호
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• pp.104-107
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• 2012

Mollugin isolated from Rubia cordifolia is known to have anti-inflammatory, anti-cancer, and anti-viral activities. In the present study, a cocktail probe assay and LC-MS/MS were used to investigate the modulating effect of mollugin on cytochrome P450 (CYP) enzymes in male ICR mice. After mollugin was orally administrated to mice at the 20, 40, or 80 mg/kg for 3 days, the activities of CYP in hepatic S-9 fractions were investigated. Unlike the selective inhibitory effect of mollugin on CYP1A2-catalyzed phenacetin O-deethylation in vitro, mollugin only significantly inhibited the activity of CYP2E1-catalyzed chlorzoxazone 6-hydroxylase in vivo. The activities of other CYPs were only slightly altered by mollugin. The results of this study suggest that mollugin might cause herb-drug interactions via the selective inhibition of CYP2E1 in vivo.