• Mass Spectrometry Letters
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• v.5 no.2
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• pp.35-41
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• 2014

Gas chromatography-mass spectrometry (GC-MS) methods have been used extensively in clinical steroid analyses. Evaluating the metabolic ratios of precursors to products by accurate quantification of individual steroid levels in biological samples can reveal the activities of enzymes associated with steroid metabolism. This review article discusses the impact of GC-MS-based steroid profiling on our understanding of the biochemical role of steroids and their metabolic enzymes in hormone-dependent diseases, such as congenital adrenal hyperplasia (CAH), cortisol-mediated hypertension, apparent mineralocorticoid excess (AME), male-pattern baldness, and breast and thyroid cancers. Steroid profiling is a comprehensive analytical technique that can be applied whenever the highest specificity is required and may be a reasonable initial diagnostic approach.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.217-226
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• 2015

Metabolite profiles of seven commercial vinegars and two traditional vinegars were performed by gas chromatography time-of-flight mass spectrometry with multivariate statistical analysis. During alcohol fermentation, yeast, nuruk, and koji were used as sugars for nutrients and as fermentation substrates. Commercial and traditional vinegars were significantly separated in the principal component analysis and orthogonal partial least square discriminant analysis. Six sugars and sugar alcohols, three organic acids, and two other components were selected as different metabolites. Target analysis by ultra-performance liquid chromatography quadruple-time-of-flight mass spectrometry and liquid chromatography-ion trap-mass spectrometry/mass spectrometry were used to detect several metabolites having antioxidant activity, such as cyanidin-3-xylosylrutinoside, cyanidin-3-rutinoside, and quercetin, which were mainly detected in Rural Korean Black raspberry vinegar (RKB). These metabolites contributed to the highest antioxidant activity measured in RKB among the nine vinegars. This study revealed that MS-based metabolite profiling was useful in helping to understand the metabolite differences between commercial and traditional vinegars and to evaluate the association between active compounds of vinegar and antioxidant activity.

• Analytical Science and Technology
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• v.18 no.2
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• pp.147-153
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• 2005

Benzophenone (BP) which is one of endocrine disrupting chemicals is suspected to contaminate waters (river, lake and industrial drainage) and soils (ground soil and sediment). Analytical method for determination of BP in soil and water was developed by gas chromatography/mass spectrometry. Water sample (100 mL) was extracted with n-hexane, and soil (10 g) was extracted with methanol and n-hexane. Recovery for BP was >71.4% in water and 86.5-94.7% in soil with coefficient variation of less than 19.8%. Calibration curves showed a good linearity ($r^2$ >0.998). In water, soil and sediment collected at nation-wide sites, BP was detected at 5 sites among 43 water sites at the concentration range of 30-200 ng/L. No BP was found in the soil and sediment samples. It is suggested that this method will be useful to the determination of BP in the environmental matrices such as waters, soils and sediments in minute quantities.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.769-773
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• 1988

The needle oils of Pious rigida Mill and Pious densiflora Sieb & Zucc were analyzed by gas chromatography/mass spectrometry. The major components of Pinus rigida were ${\alpha}-pinene$, 1-hexen-3-ol formate, sabinene, ${\beta}-pinene,\;{\alpha}-terpineol$ and ${\beta}-caryophyllene,\;{\alpha}-pinene$, bornyl acetate, ${\beta}-pinene$ and ${\beta}-hpellandrene$ were the major components fo Pious densiflora. Pious densiflora had sweeter and more greenish note than Pines rigida because the bornyl acetate content of Pious densiflora was about three times more than that of Pious rigida.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.303-308
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• 2009

Essential oils of the musk from wild muskrat (Ondatra zibethicus) were analyzed by gas chromatography/mass spectrometry. Fifty-six chemical components were separated, and 14 volatile compounds (78% of composition of total essential oil) of macrocyclic musk, mainly cyclopentadecanone, 12-hydroxy-14-methyl-oxa-cyclotetradec-6-en-2-one, cycloheptadecanone and 9-cycloheptadecen-1-one, were identified by the comparison of Wiley/NBS Library from the results of GC-MS. However, l-muscone, a compound reported by earlier workers in the musk from muskrat, was not detected using the spike test in this study. Interestingly, cyclohexadecanone, which has the same molecular weight (Mw 238) as l-muscone, was identified. In addition, it is considered that because of possessing much higher amounts of macrocyclic components compared to the original musk, muskrat has higher economic values in perfume and pharmaceutical industries.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2418-2422
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• 2011

The enantiomeric separation of lactic acid for its absolute configuration has become important task for understanding its biological origin and metabolic process involved in the formation of lactic acid. It involves the conversion of enantiomers as diastereomeric O-pentafluoropropionylated (S)-(+)-3-methyl-2-butyl ester and the direct separation by gas chromatography-mass spectrometry on a achiral capillary column. The (R)- and (S)-lactic acids were completely separated with a high resolution of 1.9. The newly developed method showed good linearity (r ${\geq}$ 0.999), precision (% relative standard deviation = 3.4-6.2), and accuracy (% relative error = -7.7-1.4) with the detection limit of 0.011 ${\mu}g/mL$. When the method was applied to determine the absolute configuration of lactic acid in Lactobacillus delbrueckii subsp. lactis 304 (LAB 304), the composition (%) of (R)-lactic acid in the cell pellet and in the culture medium were $89.0{\pm}0.1$ and $78.2{\pm}0.4$, respectively. Thus, it was verified that the present method is useful for the identification and composition test of lactic enantiomers in microorganisms.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4265-4269
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• 2011

A method based on ethyl acetate extraction and gas chromatography with tandem mass spectrometry was developed for determining tetraconazole residues in fruits and vegetables. A 10 g homogenized sample was mixed with 10 mL ethyl acetate, shaken vigorously for 3 min, stored at $-20^{\circ}C$ for 15 min, and then vortexed vigorously for 1 min; 1 g NaCl and 4 g anhydrous $MgSO_4$ were added. The clean-up was carried out by applying dispersive solid-phase with 150 mg $MgSO_4$and 50 mg primary secondary amine. Three precursor product ion transitions for tetraconazole were measured and evaluated to provide the maximum degree of confidence. Average recoveries in fruits and vegetables at three levels (0.005, 0.05 and 0.5 mg/kg) ranged from 85.53% to 110.66% with relative standard deviations ($RSD_r$) from 1.3% to 17.5%. The LODs ranged from 0.002 to 0.004 ${\mu}g$/kg, and LOQs ranged from 0.006 to 0.012 ${\mu}g$/kg. This method was also applied to determine tetraconazole residue in cucumber dissipation experiment under field conditions. The half-lives of tetraconazole in cucumber were in the range of 2.1-3.1 days.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.719-728
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• 2016

The aim of this study was to explore the volatile compounds of hind leg, foreleg, abdomen and Longissimus dorsi in both male and female Hyla rabbit meat by solid phase microextraction tandem with gas chromatography mass spectrometry, and to seek out the key odorants via calculating the odor activity value and principal component analysis. Cluster analysis is used to study the flavor pattern differences in four edible parts. Sixty three volatile compounds were detected, including 23 aldehydes, 4 alcohols, 5 ketones, 11 esters, 5 aromatics, 8 acids and 7 hydrocarbons. Among them, 6 aldehydes and 3 acids were identified as the potential key odorants according to the ratio of concentration and threshold. The contents of volatile compounds in male Hyla rabbit meat were significantly higher than those in female one (p<0.05). The results of principal component analysis showed that the first two principal component cumulative variance contributions reach 87.69%; Hexanal, octanal, 2-nonenal, 2-decenal and decanal were regard as the key odorants of Hyla rabbit meat by combining odor activity value and principal component analysis. Therefore volatile compounds of rabbit meat can be effectively characterized. Cluster analysis indicated that volatile chemical compounds of Longissimus dorsi were significantly different from other three parts, which provide reliable information for rabbit processing industry and for possible future sale.

• Analytical Science and Technology
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• v.35 no.2
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• pp.53-59
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• 2022

Mugwort (Artemisia montana), which is a perennial plant mainly distributed throughout Northeast Asian regions, has been used as a preferred source of various foods and traditional medicines in Korea. In particular, as essential oils extracted from mugwort were reported to be biologically active, its steam distillate has been widely used to treat various conditions, such as itching, hemorrhoids, and gynecological inflammation. Therefore, efforts have been devoted to develop effective methods for the collection of bioactive essential oils from mugwort. In this study, five mugwort extracts were obtained using different extraction conditions, namely, 6 % ethanol at room temperature and at 80 ℃, pure ethanol, n-hexane, and an adsorbent resin. To evaluate the five extracts of mugwort, area-under-the-curve values (AUCs), chemical profiles, and major bioactive essential oil contents were investigated using gas chromatography-mass spectrometry (GC-MS). An overall assessment of the volatile components, including essential oils, in the five extracts was conducted using AUCs, and the individual essential oil in each extract was identified. Furthermore, the four major essential oils (1,8-cineole, camphor, borneol, and α-terpineol), which are known to possess anti-microbial and anti-inflammatory activities, were quantified using authentic chemical standards. Based on the evaluation results, pure ethanol was the best extractant out of the five used in this study. This study provides evaluation results for the five different mugwort extracts and would be helpful for developing extraction methods to efficiently collect the bioactive oil components for medical purposes using chemical profiles of the extracts.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.131-134
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• 2018

The stem of Chrysanthemum morifolium, 'Baekma', were repeatedly extracted with 80% aqueous MeOH and the concentrates was partitioned into ethyl acetate (EtOAc), n-butyl alcohol and $H_2O$ fraction. The repeated silica gel and octadecyl silica gel column chromatographies for the EtOAc fractions led to isolation of two glycosyl glycerides. The chemical structures of the compounds were determined as (2S)-1-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-2,3-dilinoleoylglycerol (1) and (2S)-1-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-2,3-dipalmitoylglycerol (2) based on spectroscopic data anlyses including nuclear magnetic resonance, mass sperctrometry, and infrared spectrometry and gas chromatography mass spectrometry.