• Journal of agriculture & life science
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• v.46 no.6
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• pp.165-171
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• 2012

As a preceding study for investigating the influence of sound wave stimulus on Arabidopsis thaliana metabolomics, the polar secondary metabolomes of the plant were determined using high performance liquid chromatography coupled with tandem mass spectrometry. A total of 10 polar secondary metabolomes were characterized and quantified. Among them, 4 metabolomes, p-coumaroylagmatine isomer (7 and 8), p-coumaroylagmatine isomer (9 and 10) were identified in the plant for the first time. The validation was conducted in terms of linearity, recovery, precision, limit of detection (LOD) and limit of quantification (LOQ). The validated method was applied to the simultaneous quantification of the 10 polar secondary metabolomes.

• Food Engineering Progress
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• v.22 no.4
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• pp.295-303
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• 2018

Polyphenol profiles, physicochemical properties, antioxidant activities, and inhibitory effect of adipocyte differentiation of Houttuynia cordata fermented with Lactobacillus brevis B84 were evaluated. Six polyphenols were characterized for this plant by using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and the results were compared with total phenolic content by a spectrophotometric method. The total amount of the identified polyphenols was lower than that determined by the spectrophotometric method. However, the fermentation process influenced polyphenol composition such as content of vanillic acid and caffeic acid. The phytochemical profiles were evaluated by high-performance liquid chromatography with UV and electrospray ionization mass spectrometry detection ($HPLC-DAD-ESI-MS^n$). Total sugar and reducing sugar contents decreased after fermentation. Antioxidant activities such as DPPH, ABTS, and superoxide anion radical scavenging and reducing power were evaluated to compare the beneficial effect after fermentation. Fermented H. cordata increased the lipolytic effect in 3T3-L1 adipocytes. Overall, the results indicate that the fermentation of H. cordata with L. brevis B84 produces changes of phenolic compounds, antioxidant activity, and lipolytic effect.

• Analytical Science and Technology
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• v.34 no.4
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• pp.172-179
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• 2021

Oleanane-type triterpenoids exist as secondary metabolites in various plants. In particular, soyasaponin, an oleanane-type triterpenoid, is abundant in the hypocotyl of soybean, one of the most widely cultivated crops in the world. Depending on their chemical structure, soyasaponins are categorized as group A saponins or group DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) saponins. The different soyasaponin chemical structures present different health functionalities and taste characteristics. However, conventional phenotype screening of soybean requires a substantial amount of time for functionality of soyasaponins. Therefore, we attempted to use liquid chromatography with a photodiode array detector and tandem mass spectrometry (LC-PDA/MS/MS) for accurately predicting the phenotype and chemical structure of soyasaponins in the hypocotyl of five common soybean natural mutants. In this method, the aglycones (soyasapogenol A [SS-A] and soyasapogenol B [SS-B]) were detected after acid hydrolysis. These results indicated that the base peak and fragmentation differ depending on the chemical structure of soyasaponin with aglycone. Thus, a fragmentation database can help predict the chemical structure of soyasaponins in soyfoods and plants.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.334-338
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• 1998

Kale(Brassica oleracea var. acephala) is one of Cruciferous vegetables that is closely related to the wild ancestral form of cabbabe. The ethanol extract of kale which contains the active compoundsss under Salmonella assay system was fractionated with chloroform to collect the nonpolar solvent soluble compounds, and then further fractionation was carried out by silica gel column chromatography. Among kale extracts separated by silical gel column chromatography, the fractions of 4, 5 and 6 exhibited strong antimutagenic activities. The major active compounds from the fraction were identified as chlorophyll derivatives by the analysis with HPLC-fritp-MS. The molecular weights of each chlorophyll derivatives in the sample were acquired from the peaks of positive ion atomosphere pressure chemical ionization (APCI) mas spectrometry.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.787-793
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• 2008

A major polyphenolic compound extracted from omija (Schisandra chinensis) fruit was structurally identified, and its composition of major nutrients was investigated as well in this study. A dominating high performance liquid chromatography (HPLC) peak of water-extracted anthocyanin represented 94.1% of total absorbable compounds at 520 nm, which was further identified with HPLC-mass spectrometry (MS). As a result, mass-to-charge ratio (m/z) of the predominant anthocyanin was determined to be 727, and it was identical to molecular mass of cyanidin-3-xylosylrutinoside (Cya-3-O-xylrut). This is the first report that colorant of omija is predominantly composed of Cya-3-O-xylrut. Omija fruit contained exclusively 3 types of monosaccharide such as glucosc (0.68 g), galactose (0.01 g), and fructose (0.52 g) per 100 g of fruits. Several organic acids, citric (3.29 g), malic (1.4 g), acetic (0.4 g), and succinic acids (0.36 g) per 100 g of fruits, were detected by high performance anion exchange chromatography (HPAEC) analysis. During the compositional analysis of tree amino acid by HPLC, it was noticed that omija fruit contained substantial amount (0.01 g/100 g of fruits) of $\gamma$-amino butyric acid (GABA).

• Mass Spectrometry Letters
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• v.5 no.3
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• pp.79-83
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• 2014

Three different dutasteride extraction methods were compared and a method based on liquid-liquid extraction (LLE) using methyl tert-butyl ether and methylene chloride was proved to be more effective than others for the extraction of dutasteride and finasteride, the internal standard (IS), from rat plasma. Additionally, a method composed of the LLE extraction, liquid chromatography, and multiple reaction monitoring (MRM) to target dutasteride and IS was validated by assessing specificity, linearity ($r^2$ = 0.9993, 5 - 400 ng/mL), sensitivity (the limit of detection: 4.03 ng/mL; the limit of quantitation: 12.10 ng/mL), accuracy (intra-day: 89.4 - 105.9%; inter-day: 84.9 - 100.9%), precision (intra-day: 0.8 - 6.9%; inter-day: 2.9 - 15.9%), and recovery (84.7 - 107.8%). Since the validated method was successfully applied to a pharmacokinetic study of dutasteride, it can be useful for the pharmacokinetic evaluation of newly developed dutasteride formulations.

• Analytical Science and Technology
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• v.31 no.1
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• pp.39-46
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• 2018

Carbaryl and seven organophosphorous pesticides were analyzed simultaneously using on-line solid phase extraction (on-line SPE) coupled with liquid chromatography tandem mass spectrometry (LC/MS/MS). The target pesticides are Carbaryl, Methyl demeton, Fenitrothion, Malathion, Parathion, Phenthoate, Diazinon, and EPN. This method includes the direct injection of $500{\mu}L$ in the water sample, a 15 min separation period using a rapid resolution liquid chromatography system with on-line SPE, and detection through electrospray ionization (ESI) positive mode. The percentage of recovery of all pesticides ranged from 85.3 % to 100 %. This method showed an accuracy of ${\geq}90.0%$, possessing limits of detection and quantification within 0.05 to $0.28{\mu}g/L$ and 0.16 to $0.89{\mu}g/L$, respectively. The correlation coefficients (r) for the calibration curves within a range of 0.5 to $8.0{\mu}g/L$ were higher than 0.99. The evaluation results showed the efficacy of the method for all contents, and no pesticides were detected in the water quality sample.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.113-113
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• 2006

Polymer separations are used to obtain information on molecular distributions (molecular-weight distribution, chemical-composition distribution, functionality-type distribution, etc.). The existing methods, such as size-exclusion chromatography are reliable, but imperfect. New methods and improvements to existing methods are being studied and some of the results will be discussed. In addition, comprehensive two-dimensional liquid chromatography allows the complete characterization of two mutually dependent distributions. LCxSEC chromatograms provide a very good qualitative impression of the distributions, but calibration is not straightforward. Finally, progress in mass spectrometry allows much better information to be obtained.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.15-19
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• 2009

A simple and sensitive method for erythromycin quantification by liquid chromatography electrospray mass spectrometry (LC-MS/MS) in fishery products was developed. Samples were extracted by liquid-liquid extraction using 70% acetonitrile. Lipids were removed by acetonitrile saturated hexane. LC separation was performed on a Shiseido UG C-18 column ($150\;mm{\times}2.0\;mm$ internal diameter.) with a gradient system of 0.2% acetic acid-acetonitrile containing 0.2% acetic acid as a mobile phase at flow rate of 0.2 mL/min. The mass spectrometer was operated in selected reaction monitoring with positive electro-spray interface. Transitions were monitored a m/z $734{\to}577$ and $734{\to}158$, with m/z $734{\to}577$ chosen for quantification. Recovery of erythromycin from fish and shrimp fortified at the 10 ng/mL, 50 ng/mL and 100 ng/mL were 91.6-109.4%, 84.4-111.2% and 98.8-109.6% with high precision, respectively. Limits of quantification and limits of detection of erythromycin in both fish and shrimp were 10.0 ng/mL and 1.0 ng/mL, respectively. This analysis method for erythromycin has been proposed for registration in the Korean Official Methods of Food Analysis and has been utilized for fishery products analysis by the Korea Food and Drug Adminstration and the National Fisheries Products Quality Inspection Service.

• Journal of Life Science
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• v.29 no.2
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• pp.198-201
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• 2019

Recently, it has been reported that Bacillus mojavensis possesses antifungal properties and plant growth-promoting activities, which are similar to the characteristics of siderophore. In this study, the siderophore produced by B. mojavensis was assessed using a solid phase extraction (SPE) cartridge and liquid chromatography quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS). After B. mojavensis was incubated in phenol medium for 16 hr and lyophilized, the sample was dissolved in water and loaded to an SPE cartridge to remove interferences. The cartridge was washed with 5% methanol in water and eluted with 2% formic acid in methanol sequentially. The eluted solution was evaporated under a stream of nitrogen gas and reconstituted in methanol. The reconstituted sample was filtered, and $1{\mu}l$ of the sample was assessed using Q-TOF MS/MS. The mass spectrometer was operated using the positive electrospray ionization mode. Based on the mass spectrum and tandem mass spectrum, the siderophore produced by B. mojavensis was bacillibactin, one of the catechol types of siderophore with a molecular weight of 882.2556. This siderophore analysis could provide a justification for the study of B. mojavensis as a functional food and for pharmaceutical applications.