• Archives of Pharmacal Research
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• 제7권1호
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• pp.23-31
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• 1984

An improved mass spectrometric method for multicomponent analysis of metabolites in urine, well-suited for clinical biochemistry, is described. The method involves solvent elution of the metabolites from an adsorbent and the concentration of the eluate on a microadsorption column. This is administered by a direct inlet probe into the ionizing source of field ionization mass spectrometry (FIMS), which yield a molecular weight profile of the metabolites. The procedure provides rapidly (within one hour) reproducible profiles from a small volume of urine. The optimization of the sampling technique and the reproducibility are discussed.

• Journal of Microbiology
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• 제40권4호
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• pp.289-294
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• 2002

The fungal strain SW-3 having antimicrobial activity was isolated from soil of crucified plants in Pocheon, Kyungki-Do, Korea. Strain SW-3 was identified as Alternaria brassicicola by its morphological characteristics, and confirmed by the analysis of the 18S gene and ITS regions of rDNA. The fungus showed a similarity of 99% with Alternaria brassicicola in the 18S rDNA sequence analysis. A. brassicicola has been reported to produce an antitumor compound, called depudecin. We found that strain SW-3 produced antimicrobial metabolites, in addition to depudecin, during sporulation under different growth conditions. The metabolite of the isolated fungus was found to have strong antifungal activity against Microsporium canis and Trichophyton rubrum, and antibacterial activity against Staphylococcus aureus and Pseudomonas aerogenes. The amount and kind of metabolites produced by the isolate were affected by growth conditions such as nutrients and growth periods.

• Archives of Pharmacal Research
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• 제6권1호
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• pp.7-16
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• 1983

A methadone-diazepam interaction study in rats was performed in which conjugated metabolites of methadone were analyzed using deuterated biosynthetic internal standards. Diazepam (5mg/kg) was given to rats through a cannulate djugular vein and a subcutaneous dose of methadone (10mg/kg) was given. Bile was collecte through the cannulate dbile duct over a period of 24 hours. The deuterium label of the internal standards was found to be stable under conditions of the prolonged incubation. There was no significant difference in the excretion of the metabolites between the control and the diazepam treated rats. Feasibility of using biosynthetic internal standards with selected ion monitoring was established for the drug metabolism and kinetic studies.

• 대한유전성대사질환학회지
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• 제6권1호
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• pp.40-51
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• 2006

Purpose: A personal computer-based system was developed for automated metabolic profiling of organic aciduria and aminoacidopathy by gas chromatography-mass spectrometry and data interpretation for the diagnosis of metabolic disorders Methods: For automatic data profiling and interpretation, we compiled retention time, two target ions and their intensity ratio for 77 organic acids and 13 amino acids metabolites. Metabolites above the cut-off values were flagged as abnormal compounds. The data interpretation was a based on combination of flagged metabolites. Diagnostic or index metabolites were categorized into three groups, "and", "or" and "NO" compiled for each disorder to improve the specificity of the diagnosis. Groups "and" and "or" comprised essential and optional compounds, respectively, to reach a specific diagnosis. Group "NO" comprised metabolites that must be absent to make a definite diagnosis. We tested this system by analyzing patients with confirmed Propionic aciduria and others. Results: In all cases, the diagnostic metabolites were identified and correct diagnosis was founded to be made among the possible disease suggested by the system. Conclusion: The study showed that the developed method could be the method of choices in rapid, sensitive and simultaneous screening for organic aciduria and amino acidopathy with this simplified automated system.

• Bulletin of the Korean Chemical Society
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• 제19권1호
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• pp.45-50
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• 1998

Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2 : 1 : 10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 ㎍/㎖ in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants.

• Mass Spectrometry Letters
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• 제2권1호
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• pp.20-23
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• 2011

The purpose of this study is to investigate the in vitro metabolism of hesperetin, a bioflavonoid. Hesperetin was incubated with rat liver microsomes in the presence of NADPH and UDP-glucuronic acid for 30 min. The reaction mixture was analyzed by liquid chromatography-ion trap mass spectrometer and the chemical structures of hesperetin metabolites were characterzed based on their MS/MS spectra. As a result, a total of five metabolites were detected in rat liver microsomes. The metabolites were identified as a de-methylated metabolite (eriodictyol), two hesperetin glucuronides, and two eriodictyol glucuronides.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.432-439
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• 2020

이 연구는 급여하는 조사료와 농후사료 비율을 달리하였을 때, 우분 내 대사체 비교를 핵자기공명장치로 확인하기 위해 실시되었다. 착유중인 젖소 6마리를 두 그룹으로 나누어 조사료와 농후사료 급여 비율(HR 그룹=8:2, HC 그룹=2:8)을 달리 하였다. 우분은 직장을 통해 마리별 1회 채취 하였으며 대사체 분석은 SPE-800 MHz NMR-MS system을 이용하였다. 대사체의 정성 및 정량은 Chenomx NMR suite 8.4을 이용하였으며, 확인된 대사체들을 Metaboanalyst 4.0을 이용하여 다변량 분석, 대사경로 분석을 진행하였다. 통계분석은 SAS program을 이용하여 Dunnett's test로 그룹 간 대사체 평균값을 비교 하였다. 분석 결과, 다변량 분석에서는 그룹간의 분리가 확인 되었으며 확인된 대사체 중 통계분석에는 77개의 대사체가 이용되었다. HC 그룹에서 유의적으로 높았던 대사체는 succinate를 포함한 dimethylamine, histamine, homovanillate, thymol, acetate, propionate, butyrate, isovalerate, valerate, imidazole, N-Nitrosodimethylamine 그리고 O-Acetylcholine 이다. HC 그룹에서 분석된 대사체들의 평균 농도가 HR 그룹에 비해 높았으며, 분석된 대사경로 또한 HR 그룹에 비해 다양했다. 연구결과, 핵자기공명분광장치를 통해 분석한 우분 내 대사체는 장내 미생물 뿐 만 아니라 체내 대사 그리고 향후 축산 관련 다양한 연구에 유용하게 사용될 것으로 사료된다.

• Journal of Ginseng Research
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• 제37권3호
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• pp.371-378
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• 2013

Serum and liver metabolites in rats fed red ginseng (RG) were analyzed by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. The mass data were analyzed by partial least squares-discriminant analysis (PLS-DA) to discriminate between control and RG groups and identify metabolites contributing to this discrimination. The RG group was clearly separated from the control group on PLS-DA scores plot for serum samples, but not liver samples. The major metabolites contributing to the discrimination included lipid metabolites (lysophosphatidylcholine, acyl-carnitine, and sphingosine), isoleucine, nicotinamide, and corticosterone in the serum; the blood levels of all but isoleucine were reduced by RG administration. Not all metabolites were positively correlated with the health benefits of RG. However, the blood levels of lysophosphatidylcholine, which stimulate various diseases, and long-chain acylcarnitines and corticosterone, which activate the stress response, were reduced by RG, suggesting long-term RG might relieve stress and prevent physiological and biological problems.

• 약학회지
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• 제34권5호
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• pp.291-295
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• 1990

A modified method was investigated for the determination of benzo(a)pyrene metabolites generated by the rat liver microsomes based on the HPLC technique with radioactive flow detection. By adding $[^3H]-dexamethasone$ to the B(a)P metabolites mixture metabolized by the microsome, the poor yield of solvent extaction of B(a)P metabolites was compensated.

• 한국축산식품학회지
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• 제42권5호
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• pp.744-761
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• 2022

The liquid chromatography mass spectrometry (LC-MS)-based metabolomic and lipidomic methodology has great sensitivity and can describe the fingerprint of metabolites and lipids in pork and beef. This approach is commonly used to identify and characterize small molecules such as metabolites and lipids, in meat products with high accuracy. Since the metabolites and lipids can be used as markers for many properties of a food, they can provide further evidence of the foods authenticity claim. Chromatography coupled to mass spectrometry is used to separate lipids and metabolites from meat samples. The research data usually is compared to lipid and metabolite databases and evaluated using multivariate statistics. LC-MS instruments directly connected to the metabolite and lipid databases software can be used to assess the authenticity of meat products. LC-MS has good selectivity and sensitivity for metabolomic and lipidomic analysis. This review highlighted the combination of metabolomics and lipidomics can be used as a reference for analyzing authentication meat products.