• 한국식품영양과학회지
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• 제32권8호
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• pp.1390-1393
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• 2003

동위 원소를 이용하여 골조직 collagen과 같이 대사속도가 느린 단백질의 합성 속도를 측정 할 때 가장 중요한 점은 전구체 공급원의 비균일성 및 복잡한 대사경로로 인한 해석상의 제한점을 극복하기 위하여 동위원소가 함유된 전구체를 지속적으로 투여하여 동위원소공급원의 항상성을 유지하는 것이다. 이 경우 precursor-product kinetics를 적용하여 $k_{s}$값을 정확하게 측정할 수 있다. $^2$$H_2O$는 저렴한 안정동위 원소 추적자로서 독성이나 부작용 없이 장기간 공급 가능하고 공급방법 또한 간단하다. 본 연구에서는 골조직 collagen 합성속도를 아미노산에 $^2$$H_2O$를 치환하는 precursor-product 방법으로 측정하였으며, 골조직 collagen으로부터 분리한 아미노산의 동위 원소함량을 GC/MS로 분석하였다. 실험 기간동안 체액의 $^2$$H_2O$는 2.7 ∼ 3.0% 수준으로 일정하게 유지되었고 성장기 흰쥐 골조직의 collagen 합성속도는 $k_{s}$(OH-pro) = 0.066$\pm$0.049 w $k^{-1}$였다. 동위원소를 연속적으로 공급해야하는 precursor product방법은 교체율이 느린 단백질에 적용하는데 기술적인 어려움이 있었지만, 안정하고 저렴한 $^2$$H_2O$ 특성으로 인하여 precursor-product방법을 교체율이 느린 단백질에 적용하는 것이 가능하게 되었다..

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.283-283
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• 2006

Multigram-scale product exclusively containing magnetic carbon nanoparticles (MNCPs) with uniform size was successfully fabricated without a specific separation process. The iron-doped PPy nanoparticles were synthesized by micelle templating and used as the carbon precursor in order to generate MCNPs. The magnetic carbon nanoparticles possessed a microporous structure and exhibited ferromagnetic properties at room temperature. This approach may be an effective alternative to generate magnetic carbon nanoparticles against the conventional arc-discharge technique.

• Mass Spectrometry Letters
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• 제5권4호
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• pp.115-119
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• 2014

The Brazil nut (Bertholletia excelsa - Lecythidaceae) is considered a product with high economic value, being a food widely appreciated for its nutritional qualities. Although previous studies have reported the biochemical composition of Brazil nut oil, the knowledge regarding the phospholipid composition exhibits a disagreement: the composition of fatty acids present in the structures of phospholipids is reported as being different from the composition of the free fatty acids present in the oil. In this work, solid phase extraction (SPE) was employed to provide a fast extraction of the phospholipids from Brazil nuts, in order to compare the phospholipid profile of the in nature nuts and their fatty acids precursor present in the oil. The major phospholipids were characterized by mass spectrometry approach. Their fragmentation pattern through direct infusion electrospray ionization ion-trap tandem mass spectrometry ($ESI-IT-MS^2$) proved to be useful to unequivocal characterization of these substances. High resolution (HR) experiments through ESI using a quadruple time of flight mass spectrometry (QTOF) system were performed to reinforce the identifications.

• 약학회지
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• 제44권5호
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• pp.391-398
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• 2000

Leptin, the product of the ob gene, is a small peptide molecule synthesized by white adipocytes with an important role in the regulation of body fat and food intake. Based on the evidence that synthesis of leptin is regulated by female sex hormone, estrogen, this present study was investigated whether sex hormone precursor DHEA, can regulate obese gene expression in lean and genetically obese (ob/ob) mice. Antiobesity activity of DHEA was evaluated by determining body weight, food consumption, epididymal fat weight and serum levels of cholesterol and triglyceride in ICR, C57BL/6J, and ob/ob mice. The treatment of C57BL/6J lean and obese mice with a diet containing 0.3% and 0.6% DHEA resulted in lowered rates of weight gain in comparison to non-treated mice, although much greater response was found in the obese mice. All other concentrations of DHEA (0.015%, 0.06%, 0.15%, 0.3%) except the highest one(0.6%) showed no significant effects on weight gain in ICR mice. Food consumption was significantly decreased in all mice treated with 0.6% DHEA, whereas it was not decreased in ICR mice at lower concentrations than 0.6% DHEA. DHEA decreased significantly epididymal adipose tissue weight and serum triglyceride levels dose dependently in lean and obese mice. However serum cholesterol levels were decreased at lower concentrations than 0.15% DHEA and increased at concentrations of 0.3% and 0.6% DHEA in lean and obese mice. These increases in serum cholestrol levels at high concentrations of DHEA might result from the fact that DHEA has a cholesterol moiety thereby interfered the assay system. As an approach to elucidate the mechanism for antiobesity activity of DHEA, we examined mRNA levels of obese gene in the adipocyte and obese gene product (leptin) in the serum. The results showed that DHEA did not affect obese gene expression in ICR and C57BL/6J mice. Therefore, we concluded that antiobesity activity of DHEA was not modulated by obese gene expression.

• 한국대기환경학회지
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• 제33권1호
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• pp.54-63
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• 2017

Atmospheric nitrogen containing organic compounds(e.g. amino acids) has attracted considerable attention from the viewpoint of the oceanic biogeochemical cycle of nitrogen as well as the long range transfer. However, only a few measurements of organic nitrogen compounds have been conducted due to analytical difficulties. In this study, total of nine amino acids such as Glutamic acid, Histidine, Arginine, Tyrosine, Cystine, Valine, Methionine, Phenylalanine, Lysine have been analytically determined by Liquid Chromatography - Mass Spectrometry Mass Spectrometry (LC-MSMS). As results, Fragmentor Voltage (FV), Precursor Ion, Collision Energy, Product Ion related to individual amino acid compounds are shown. Based on the operational conditions, Lysine, Glutamine Acid, Tyrosine were analyzed during the China Oriented Smog Period. High concentrations of Lysine, Glutamine Acid, and Tyrosine are discussed with organic carbon (OC), elemental carbon (EC), and water soluble ions. The results can provide to understand the sources with aging process related to amino acids influenced by the long-range transport from the Yellow Sea area.