• Bulletin of the Korean Chemical Society
• /
• 제30권2호
• /
• pp.363-367
• /
• 2009

An isotope-dilution flow-injection electrospray/mass spectrometric method was developed for the accurate determination of glucosamine contents in pharmaceutical formulations. Samples were extracted by methanol. After spiking glucosamine-1-$^{13}C_1$ as an internal standard, the extracts were then analyzed by flow-injection ESI/MS in a selected ion monitoring (SIM) mode to detect [M+H]$^+$ ions of the analyte and its isotope analogue at m/z 180 and m/z 181, respectively. Confirmatory measurements were made by selectively monitoring the collisionally induced dissociation channels of m/z 180 $\rightarrow$ m/z 72 and m/z 181 $\rightarrow$73, respectively, to test the possibility of bias in the SIM method due to matrix interferences, but any significant bias in the SIM mode was not observed. Repeatability and reproducibility studies showed that the flow-injection ESI/MS method is a reliable and reproducible method which can provide a typical method precision of 1.0 %. Other results for the method validation are reported.

• Bulletin of the Korean Chemical Society
• /
• 제25권12호
• /
• pp.1791-1800
• /
• 2004

Angiotensin I, a model decapeptide, was glycosylated and partially hydrolyzed with HCl (6 N, 80 $^{\circ}C$, 4 h), aminopeptidase, and carboxypeptidase Y. A single peptide mass map obtained from truncated peptides in the partial acid hydrolysate of angiotensin and its glycosylation product mixture by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry enabled sequencing of angiotensin by a combinatorial procedure. MALDI-TOF and electrospray ionization (ESI) tandem mass spectrometric results indicate that both the N-terminal amino group of aspartic acid and the guanidinium group of the second residue arginine are glycosylated.

• Journal of Applied Biological Chemistry
• /
• 제66권
• /
• pp.338-344
• /
• 2023

Curcuma longa is a plant belonging to the genus Curcuma and is distributed across various Asian regions. This plant is widely known for its rhizomes, which possess a variety of pharmacological properties. However, although the leaves and stems of this plant also contain several health-promoting secondary metabolites, very few studies have characterized these compounds. Therefore, our study sought to quantify the secondary metabolites from the leaves and stems of Curcuma longa L. (LSCL) using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) and high-performance liquid chromatography (HPLC). Our LC-ESI-MS analyses detected twenty-one phenolic compounds in the LSCL, among which fifteen compounds were detected via HPLC analysis. Four compounds, namely vanillic acid (0.129 mg/g), p-coumaric acid (0.431 mg/g), 4-methylcatechol (0.199 mg/g), and afzelin (0.074 mg/g) were then quantified. These findings suggest that LSCL is rich in secondary metabolites and holds potential as a valuable resource for the development of functional and nutritional supplements in the future.

• Archives of Pharmacal Research
• /
• 제22권2호
• /
• pp.189-193
• /
• 1999

Reversed-phase high-performance liquid chromatography/mass spectrometry (HPLC/MS) with an eletcrospray ionization (ESI) interface was applied to the identification of metabolites of IY81149 in the rat plasma. Fragments obtained using collision-induced dissociation (CID) in both positive and negative modes were utilized to elucidate the structure of metabolites. The eluent from the conventional HPLC column was split and directly introduced into an ESI-mass spectrometer for the identification of the structures. the CID technique allowed the sensitive identification of sulfonyl-IY81149 and hydroxy-IY81149 from the rat plasma.

• 대한임상약리학회:학술대회논문집
• /
• 대한임상약리학회 2007년도 추계학술대회
• /
• pp.92-93
• /
• 2007

See Full Text

• 분석과학
• /
• 제24권3호
• /
• pp.173-182
• /
• 2011

약물(Prostanozol)을 복용한 여성을 대상으로 한 뇨시료 중에 함유된 Prostanozol 및 그 대사체들을 검출하기 위해 LC/ESI/MS와 GC/TOF-MS를 이용하여 효과적으로 분리 및 검출하였고, LC/ESI/MS의 질량스펙트럼으로부터는 각각의 분자량을 추정하였으며 GC/TOF-MS로는 이들을 확인하였다. M1은 Prostanozol의 17번 탄소가 케톤기로 치환된 17-keto-Prostanozol, M2는 M1에서 pyrazole nucleus 와 Aring에 한 개의 히드록시기가 치환된 hydroxy-17-keto-Prostanozol, M3는 B-ring 또는 C-ring에 한 개의 히드록시기가 치환된 hydroxy-17-keto-Prostanozol, M4는 한 개의 히드록시기가 D-ring에 치환된 hydroxy-17-keto-Prostsnozol로 확인되었으며 M5는 17번 탄소 위치에 히드록시기를 갖고 B-ring 또는 C-ring에서 하나의 히드록시기가 치환된 hydroxy-17-hydroxy-Prostanozol로 추정되며 M6은 17번 탄소 위치에 케톤기를 갖고 pyrazole nucleus 혹은 A-ring에 하나의 히드록시기를 또한 B-ring 또는 C-ring에 또 하나의 히드록시기가 치환된 dihydroxy-17-keto-Prostanozol, M7은 M6와 같이 17번 탄소에 케톤기를 갖으며 pyrazole nucleus 혹은 A-ring에 하나의 히드록시기를, 또한 D-ring에 또 하나의 히드록시기를 가진 dihydroxy-17-keto-Prostanozol로 확인되었다. 마지막으로 M8은 pyrazole nucleus 혹은 A-ring에 하나의 히드록시기를 갖고 그 외의 ring에 또 다른 히드록시기가 치환된 dihydroxy-17-hydroxy-Prostanozol임을 확인할 수 있었다. 이중 M5, M7, 그리고 M8은 지금까지 밝혀지지 않았던 새로운 대사체였다. 체내에서의 포합반응 여부를 확인한 결과 Prostanozol과 8종의 모든 대사체가 글루쿠론산 포합체를 형성하였고, 8종의 대사체 중 일부는 포합체를 형성하지 않고도 배출되며 특히 M6과 M7은 황산 포합체로도 배설되는 것을 확인할 수 있었다.

• 분석과학
• /
• 제20권5호
• /
• pp.424-433
• /
• 2007

혈장시료 중의 갑상선 호르몬을 고체상 추출법을 이용하여 추출한 후 HPLC/DAD/ESI-MS (high-performance liquid chromatograph/diode array detector/electrospray ionization-mass spectrometer)를 사용하여 분석하였다. 7종의 thyroid hormones의 HPLC 분리조건은 Hypersil ODS 컬럼(4.6 mm I.D., 250 mm length, particle size $5{\mu}m$)을 사용하고 ammonium formate buffer와 아세토나이트릴을 이동상으로 하여 기울기 용리한 결과 완전 분리가 가능하였으며, UV spectra 및 질량스펙트럼을 확인할 수 있었다. 고체상추출법에 의한 전처리 최적 조건을 조사한 결과 시료를 pH 3으로 한 후 C18 고체상을 사용하여 4 mL의 메탄올로 용리할 경우 회수율이 74.5-115.7%로 나타났다. HPLC/ESI-MS를 이용하여 20-500 ng/mL범위에서 검량선을 작성한 결과 $r^2$값은 0.9939-0.9978으로 나타났으며 검출한계는 20-50 ng/mL (38.1-162.8 pmol/mL)로 계산되었다. 정상인의 혈장에서 thyroxine의 정량이 가능하였으며 그 결과 50.98-112.97 ng/mL로 검출되었다.

• Mass Spectrometry Letters
• /
• 제3권3호
• /
• pp.78-81
• /
• 2012

The hydrophobic hydrocarbon chain and the polar sulfate group confer surfactant properties and enable them to be used as anionic surfactants. Anionic surfactants (AS) are known for their adverse impact on environment, particularly on aquatic ecosystem. In the present study a fast, sensitive and selective method for the determination and subsequent quantification of six anionic surfactants was developed using hydrophilic interactive liquid chromatography (HILIC) coupled to a electrospray ionization (ESI) mass spectrometer (MS), in the concentration range 15-20 ${\mu}g/L$. The capability of the method was established using regression analysis and ANOVA. The method performance was evaluated by analyzing real time surface water spiked with 1-dodecyl hydrogen sulfate at 15 ${\mu}g/L$. Combined efficiency of solid phase extraction and MS detection established recovery of 89% in presence of natural matrix. These results point out that HILIC coupled to multistage MS procedures can be a powerful technique for environmental applications concerning the screening of polar contaminants.

• Bulletin of the Korean Chemical Society
• /
• 제30권6호
• /
• pp.1257-1261
• /
• 2009

We present the theoretical and experimental results of $^{31}P$ NMR and low energy CID MS/MS study of $Hg^{2+}$ binding to fenitrothion (FN). The calculated $^{31}P$ NMR chemical shifts order for FN with $Hg^{2+}$ complex is in good agreement with experimental $^{31}P$ NMR chemical shifts order. The experimental and theoretical $^{31}P$ NMR study of organophosphorus pesticide with $Hg^{2+}$ gives to important information for organophosphorus pesticide metal complexes. ESI-MS and low energy CID MS/MS experiments of $Hg^{2+}$-FN complexes combined with accurate mass measurements give insight into the metal localization and allow unambiguous identification of fragments and hydrolysis products.

• Mass Spectrometry Letters
• /
• 제4권4호
• /
• pp.83-86
• /
• 2013

A new interface for coupling CIEF and MS using a four-way cross has been developed in a single mechanical system. This new interface could be operated without the electric discontinuity and reinstallation of lines. Additionally, a bare fused silica capillary was facilitated as a spray needle to produce electrospray and to guide catholyte or sheath liquid. Focusing for CIEF was completed in a hanging droplet at the end of spray needle. This capillary spray needle also provided stable spray, enhanced the ionization efficiency and increased sensitivity. Results with carbonic anhydrase I showed that focusing and spraying were well completed with the new interface and the new spray needle.