• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1170-1178
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• 2011

In the present study, the approach of high accuracy mass measurements for phospholipid identifications was evaluated using a 7 T ESI-FTMS/linear ion trap MS/MS. Experiments were carried out for porcine brain, bovine liver, and soybean total lipid extracts in both positive and negative ion modes. In total, 59, 55, and 18 phospholipid species were characterized in the positive ion mode for porcine brain, bovine liver, and soybean lipid extracts, respectively. Assigned lipid classes were PC, PE, PEt, PS, and SM. In the negative ion mode, PG, PS, PA, PE, and PI classes were observed. In the negative ion mode, for porcine brain, bovine liver, and soybean lipid extracts, 28, 34, and 29 species were characterized, respectively. Comparison of our results with those obtained by other groups using derivatization-LC-APCI MS and nano-RP-LC-MS/MS showed that our approach can characterize PC species as effectively as those methods could. In conclusion, we demonstrated that high accuracy mass measurements of total lipid extracts using a high resolution FTMS, particularly, 7T FTMS, plus ion-trap MS/MS are very useful in profiling lipid compositions in biological samples.

• Mycobiology
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• v.38 no.4
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• pp.302-309
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• 2010

Formic acid is a representative carboxylic acid that inhibits bacterial cell growth, and thus it is generally considered to constitute an obstacle to the reuse of renewable biomass. In this study, Saccharomyces cerevisiae was used to elucidate changes in protein levels in response to formic acid. Fifty-seven differentially expressed proteins in response to formic acid toxicity in S. cerevisiae were identified by 1D-PAGE and nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analyses. Among the 28 proteins increased in expression, four were involved in the MAP kinase signal transduction pathway and one in the oxidative stress-induced pathway. A dramatic increase was observed in the number of ion transporters related to maintenance of acid-base balance. Regarding the 29 proteins decreased in expression, they were found to participate in transcription during cell division. Heat shock protein 70, glutathione reductase, and cytochrome c oxidase were measured by LC-MS/MS analysis. Taken together, the inhibitory action of formic acid on S. cerevisiae cells might disrupt the acidbase balance across the cell membrane and generate oxidative stress, leading to repressed cell division and death. S. cerevisiae also induced expression of ion transporters, which may be required to maintain the acid-base balance when yeast cells are exposed to high concentrations of formic acid in growth medium.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.289-296
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• 2019

A novel rapid procedure with liquid chromatography tandem mass spectrometry (LC-MS/MS) detection has been developed by changing various conditions including sample preparation such as QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) methodology. This work has been involved the optimization and validation of detection method for fluoroquinolones which are widespread used in livestock especially in the chicken. Five grams of homogenized chicken muscle were extracted with QuEChERS EN and acetonitrile containing 5% formic acid and cleaned with anhydrous magnesium sulfate and C₁₈ sorbent. The separation was performed on Acquity UPLC HSS T3 (2.1 mm×100 mm, 1.8 ㎛) column. The mobile phase A and B were composed of water containing 0.1% formic acid and acetonitrile containing 0.1% formic acid, respectively. Flow rate was 0.25 mL/min and column temperate was 40℃. LC-MS/MS with multiple reaction monitoring has been optimized for ten fluoroquinolones (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, marbofloxacin, norfloxacin, ofloxacin, orbifloxacin, pefloxacin and sarafloxacin). The method developed in this study has been presented good linearity with correlation coefficient (R²) of 0.9971~0.9998. LOD and LOQ values ranged from 0.09 to 0.76 ppb and from 0.26 to 2.29 ppb, respectively. The average recoveries were from 77.46 to 111.83% at spiked levels of 10.0 and 20.0 ㎍/kg. Relative standard deviation (%) ranged 1.28~11.90% on intra-day and 3.10~8.38 % on inter-day, respectively. This analysis method was applicable to the livestock residue laboratories and was expected to be satisfactory for the residue surveillance system.

• Analytical Science and Technology
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• v.28 no.6
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• pp.436-445
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• 2015

Amomi Fructus with anti-oxidative activity was chosen and essential oil was obtained by SDE (simultaneous distillation extraction), and 39 constituents were determined by GC-MS (gas chromatography-mass spectrometry). Major components were camphor, borneol acetate, borneol, D-limonene and camphene. Three solvent extracts such as hexanes, diethyl ether and methylene chloride from Amomi Fructus were obtained. These were analyzed by GC-MS and 4 more constituents were identified in addition to 39 components discovered in essential oil. Five major components such as camphor, borneol acetate, borneol, D-limonene and camphene were also detected, however the relative peak percents of those components were different from those of constituents in essential oil. To estimate the kind and the amount of materials evaporated at certain temperature and conditions from essential oil and solvent extracts, dynamic headspace apparatus was used and materials evaporated and trapped at certain conditions were analyzed by GC-MS. Recovery yield of SDE method from Amomi Fructus was measured by using camphor and standard calibration solution of camphor methanol solution and, the yield was 82.0%. Content of Hg was measured by mercury analyzer and contents of Cd, Pb, Cr, Mn, Co, Ni, Cu and Zn in Amomi Fructus, essential oils and solvent extracts were determined by ICP-MS (Inductively coupled plasma-mass spectrometer). Pb, Cd and Hg were measured in the concentration of 0.72 mg/kg, <0.10 mg/kg and 0.0023 mg/kg, respectively and these were below permission level of purity test. Contents of Mn, Cu and Zn in Amomi Fructus were 213 mg/kg, 8.29 mg/kg and 31.0 mg/kg, respectively and which were relatively higher than other metals such as Cr, Co and Ni. Metals such as Mn (0.65 ~ 9.08 mg/kg), Cu (1.16 ~ 4.40 mg/kg) and Zn (1.10 ~ 3.80 mg/kg) in essential oil and solvent extracts were detected. At this point it is not clear that the metals were cross-contaminated in the course of treating Amomi Fructus or metals were contained in Amomi Fructus. The influence evaluation toward biological model study of these metals in essential oil and solvent extracts will be needed.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.488-492
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• 2005

The purpose of this study is to investigate the bioequivalence of two haloperidol 5 mg tablets, Myung In haloperidol (Myung In Pharm. Co., Ltd., test drug) and $Peridol^{R}$(Whanin Pharm. Co., Ltd., reference drug), and also to estimate the pharmacokinetic parameters of haloperidol in Korean volunteers. The bioavailability and pharmacokinetics of haloperidol tablets were examined on 24 healthy volunteers who received a single oral dose of each preparation in the fasting state in a randomized balanced 2 way crossover design. After an oral dosing, blood samples were collected for a period of 60 h. Plasma concentrations of haloperidol were determined using a liquid chromatographic electrospray mass spectrometric (LC-MS) method. The pharmacokinetic parameters were calculated with noncompartmental pharmacokinetic analysis. The geometric means of $AUC_{0-60h} and C_{max}$ between test and reference formulations were $17.21\pm8.26 ng\cdot/mL vs 17.31\pm13.24 ng\cdot/mL and 0.87\pm0.74 ng/mL vs 0.85\pm0.62 ng/mL$. respectively. The $90\%$ confidence intervals of mean difference of logarithmic transformed $AUC_{0-60h} and C_{max} were log0.9677{\sim}log1.1201 and log0.8208{\sim}log1.1981$, respectively. It shows that the bioavailability of test drug is equivalent with that of reference drug. The geometric means of other pharmacokinetic parameters ($AUC_{inf}. t_{1/2}, V_{d}/F, and CL/F$) between test drug and reference drug were $21.75\pm8.50 ng{\cdot}h/mL vs 21.77\pm15.63 ng{\cdot}h/mL, 29.87\pm8.25 h vs 29.60\pm7.56 h, 11.51\pm5.45 L vs 12.90\pm6.12 L and 0.26\pm0.09 L/h vs 0.31\pm0.17 L/h$, respectively. These observations indicate that the two formulation for haloperidol was bioequivalent and, thus, may be clinically interchangeable.

• Korean Journal of Plant Resources
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• v.30 no.1
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• pp.17-21
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• 2017

Since the acetylcholinesterase (AChE) inhibitor is used to treat Alzheimer's disease, the present study aimed to analyze the component with anti-AChE activity from the essential oil of Artemisia iwayomogi (Compositae). The four major components of the essential oil were identified to be camphor (29.8%), borneol (28.0%), eucalyptol (5.81%) and coumarin (5.49%) from a gas chromatography-mass spectrometry (GC-MS). The essential oil and its three components, camphor, borneol, and coumarin, were subjected to anti-AChE assay. The $IC_{50}$ values of the essential oil and coumarin were shown to be $0.298mg/m{\ell}$ and $0.236mg/m{\ell}$, though those of other two components, camphor and borneol, were more than $0.250mg/m{\ell}$. These results suggest that coumarin is an active substance of this essential oil with anti-AChE activity.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.303-314
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• 2020

Gambir is a non-wood forest product with a potential of being used as wood adhesive, due to about 33% catechin in it. Meanwhile, catechins and sucrose have not been studied as adhesives. Therefore, basic characteristics of gambir-sucrose adhesives were investigated. In this research, adhesives were prepared by dissolving gambir and sucrose in distilled water, at different blending ratios of the gambir/sucrose such as 100/0, 75/25, 50/50, and 25/75 wt%. Furthermore, gas chromatography-mass spectrometry (GC-MS) was employed to determine the gambir chemical compositions, and Fourier transform-infrared (FTIR) spectroscopy was carried out to identify chemical bonds. Particleboards with a target density of 0.8 g/㎤ were then manufactured by hot-pressing for 10 min at 200℃. The internal bond (IB) strength of particleboard was subsequently measured. Based on the GC-MS analysis, 31.11% of catechin was identified. In addition, the viscosity, density, solid content, and gelation time of the adhesives, and insoluble matter content (IMC) in boiling water were 7.30~33.24 mPa.s, 1.2~1.3 g/㎤, 25.56~28.44%, 73~420 min, and 29.75~62.10%, respectively. Adding sucrose to the adhesive was observed to raise the IMC from 49.05 to 62.10%, at 180℃ and 200℃. FT-IR analysis showed that the gambir absorption peaks occurred at approximately 1620 cm^-1, assigned to the C=O stretching of 5-hydroxymethylfurfural, which tended to increase with the addition of sucrose. The reaction between gambir and sucrose was observed in the form of the dimethylene ether bridge. The 25/75 wt% gambir-sucrose adhesives and 200℃ hot-pressed temperature resulted in the highest IB strength (0.89 MPa), and met the requirement of JIS A5908-2003 type 18. Consequently, the gambir-sucrose adhesive could be used as a particleboard adhesive.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.814-821
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• 1996

An attempt was made to determine the effects of drying methods including shady air drying, presteamed and shady air drying, microwave drying, and freeze drying on the volatile flavor components of Capsella bursapastoris. Essential oils from the samples were isolated by Simultaneous steam distillation-extraction (SDE) method using diethyl ether as solvent. Concentrated samples were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Respective 30, 18, 29, and 26 volatile flavor components were identified in shady air dried samples, presteamed and shady air dried samples, microwave dried samples, and freeze dried samples. The kinds and amounts of volatile flavor components evidently depended upon the drying methods. Trimethyl sulfide was regarded as the most abundant component in shady air dried samples, dimethyl trisulfide in presteamed and shady air dried samples, and phytol in microwave or freeze dried samples.

• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.21-29
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• 2002

To identify and evaluate the dichlorobenzidine(DCB)-DNA adducts in liver cell and bladder epithelial cells by $^{32}$ P-postlabeling and GC/MS-SIM, we orally exposed the dichlorobenzidine(20mg/kh body wt./day) to male Sprague-Dawley rats(l85$\pm$10g) for 14 days. Two kinds of DCB-DNA adduct(A1 and A2) were found at the same site of thin layer chromatogram of $^{32}$ P-postlabeling method in liver cells and bladder epithelial cells. In liver cells, relative adduct labeling(RAL) $\times$ 10$^{12}$ of DCB-DNA adduct A1 were 34.1$\pm$3.71 and 69.9$\pm$5.02, that of adduct A2 were 74.1$\pm$10.1 and 105.1$\pm$10.1 on 10 and 14 days after treatment, respectively. And in bladder epithelia cells, RAL $\times$ 10$^{12}$ of DCB-DNA adduct A1 were 5.92$\pm$1.60 and 15.9$\pm$1.31, that of adduct A2 were 9.81$\pm$2.81 and 22.8$\pm$1.79 on 10 and 14 days after treatment, respectively. DCB metabolites formed DNA adducts were monoacetyl-dichlorobenzidine(acDCB) and diacetyl-dichlorobenzidine(di-acDCB), which was identify by gas chromatography/mass spectrometry-scan ionization mode(GC/MS-SIM), after hydrolysis of DCB-DNA adducts isolated from live cells and bladder epithelial cells. The base peak of acDCB were 252 and 294 m/z, and that of di-acDCB were 252, 294 and 336 m/z. In conclusion, the exposed DCB formed two kinds of DCB-DNA adduct, the proximate materials of that were acDCB and di-acDCB in liver and bladder epithelial cells. And the above GC/MS-SIM method was found the DCB-DNA adducts could be monitoring by gas chromatography.

• Food Engineering Progress
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• v.13 no.1
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• pp.38-43
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• 2009

In this research, the contents of capsaicin and dihydrocapsaicin in various species of red pepper produced in the Goesan-gun County were determined by GC-MS. Further, the contents of capsaicin and dihydrocapsaicin in powdered red pepper products with very hot, hot, normal and mild taste were analyzed to present the degree of hot taste in their products based on contents of capsaicin. The contents of capsaicin in each species of red pepper were from 25.18 mg%(Daetong) to 123.62 mg%(Cheongyang). In the powdered red pepper sold in the market, the contents (mg%) of capsaicin in very hot, hot, normal and mild taste products were 101.98, 67.63, 37.74, and 14.73, respectively. Based on this result, the classification of hot taste by contents of capsaicin was presented in the 7 grades. Namely, the products currently sold in the market were classified into very hot, hot, normal and mild taste. In this research, the degree of hot taste was classified based on contents of capsaicin into 1st grade over 120 mg%, 2nd grade in 100-120 mg%, 3rd grade in 80-100 mg%, 4th grade in 60-80 mg%, 5th grade in 40-60 mg%, 6th grade in 20-40 mg% and 7th grade below 20 mg%. Thus, it is expected that the problem which arises when preparing the products such as kimchi, gochujang and seasoning sauces by using powdered red pepper, namely, the inconsistency of hot taste can be improved and maintained.