• Analytical Science and Technology
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• v.25 no.6
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• pp.435-440
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• 2012

A liquid chromatography-electrospray ionization-tandem mass spectrometry method (LC-ESI-MS/MS) was used for determining perchlorate in the Gum-River surface water. Sample was directly injected into LC-ESI-MS/MS after the filtrations using PTFE filter paper. The coefficient of variation of perchlorate was less than 3% and the limit of quantification was 0.17 ${\mu}g/L$. Water samples were collected from thirty-five basins of Gum-River on February, April and June 2012, respectively. As a result, perchlorate was detected in the concentration range of 0.23-3.73 ${\mu}g/L$ (mean 0.20 ${\mu}g/L$) in the frequency of 15% in general surface water and in the concentration range of 0.36-25.10 ${\mu}g/L$ (mean 1.69 ${\mu}g/L$) in the frequency of 36% in surface water samples near industry area.

• Mass Spectrometry Letters
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• v.2 no.4
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• pp.92-95
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• 2011

Pyrophosphates are the key intermediates in the biosynthesis of isoprenoids, and their concentrations could reveal the benefits of statins in cardiovascular diseases. Quantitative analysis of five pyrophosphates, including isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP), farnesyl pyrophosphate (FPP), and geranylgeranyl pyrophosphate (GGPP), was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in negative ionization mode. After dilution with methanol, samples were separated on a 3 ${\mu}m$ particle multi-modal $C_{18}$ column ($50{\times}2$ mm) and quantified within 10 min. The gradient elution consists of 10 mM ammonium bicarbonate and 0.5% triethylamine (TEA) in water and 0.1% TEA in 80% acetonitrile was used at the flow rate of 0.4 mL/min. Overall recoveries were 51.4-106.6%, while the limit of quantification was 0.05 ${\mu}g$/mL for GPP and FPP and 0.1 ${\mu}g$/mL for IPP, DMAPP, and GGPP. The precision (% CV) and accuracy (% bias) of the assay were 1.9-12.3% and 89.6-111.8%, respectively, in 0.05-10 ${\mu}g$/mL calibration ranges ($R^2$ > 0.993). The devised LC-MS/MS technique with the multi-modal $C_{18}$ column can be used to estimate the biological activity of pyrophosphates in plasma and may be applicable to cardiovascular events with cholesterol metabolism as well as the drug efficacy of statins.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.300-314
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• 2014

An ultra-performance liquid chromatography-electrospray ionization-mass spectrometer (UPLC-ESI-MS) method was established for the simultaneous quantification of eighteen marker compounds in traditional Korean formula, Cheonwangbosimdan (CWBSD). In addition, we evaluated the antioxidant effects of CWBSD. Eighteen marker components were separated on a UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) and kept at $45^{\circ}C$ by gradient elution with 0.1% (v/v) formic acid in water and acetonitrile as mobile phase. The flow rate was 0.3 mL/min and the injection volume was $2.0{\mu}L$. The antioxidant activities of CWBSD were assessed by measuring free radical scavenging activities on 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 1-1-diphenyl-2-picrylhydrazyl (DPPH). The calibration curves of all analytes showed good linearity (correlation coefficient ${\geq}0.9937$) within the test ranges. The limits of detection and quantification for the 18 marker compounds were 0.01-4.71 ng/mL and 0.03-14.13 ng/mL, respectively. The contents of the 18 compounds in CWBSD extract ranged from none to $1701.00{\mu}g/g$. The CWBSD showed the radical scavenging activity in a dose-dependent manner. The concentration required for 50% reduction ($RC_{50}$) against ABTS and DPPH radicals were $149.42{\mu}g/mL$ and $339.24{\mu}g/mL$.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.342-348
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• 2011

Bacillus subtilis EBS05, an endophytic bacteria strain isolated from a medicinal plant Cinnamomum camphor, can produce antagonistic compounds that effectively inhibit plant pathogenic fungi. The greenhouse experiments showed that wheat sharp eyespot disease (WSED) was reduced by 91.2%, 88.2% and 43.0% after the treatment with fermentation broth, bacteria-free filter and a fungicide fludioxonil, respectively. The culture broth of strain EBS05 can more effectively control WSED than can fludioxonil. The fermentation broth and bacteria-free filter ability to suppress WSED was not significantly different, suggesting that an active secreted substance played a major role in controlling WSED. Separation and purification of the active compounds was carried out by serial processes, including hydrochloric acid (pH 2.0) treatment, methanol extraction and Sephadex LH-20 column chromatography, silica gel column chromatography and reverse-phase high-pressure liquid chromatography (HPLC), respectively. The purified compounds, one of active peaks in the HPLC spectrum, were obtained from the collection. Analysis of the chemical structures by time-of-flight mass spectrometry (TOF-MS) and electrospray ionization mass spectrometry/mass spectrometry (ESI-MS/MS) showed that the active substances produced by the endophytic bacteria EBS05 are mixture of the ${\beta}$-hydroxy-C12~C15-$Leu^7$ surfactin A isomers with 1035.65 Da, 1021.64 Da, 1007.63 Da and 993.65 Da molecular weights, respectively.

• Korean Journal of Pharmacognosy
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• v.47 no.4
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• pp.381-388
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• 2016

Hyangso-san is a traditional herbal medicine that consists of the seven herbal medicines, Cyperi Rhizoma, Perillae Folium, Atractylodis Rhizoma, Citri Unshius Pericarpium, Glycyrrhizae Radix et Rhizoma, Zingiberis Rhizoma Crudus, and Allii Fistulosi Bulbus. Hyangso-san has long been clinically used to treat the influenza, including headache, ferver, chills, and pantalgia. In this study, we were performed the simultaneous analysis of the 15 marker compounds (liquiritin apioside, liquiritin, ferulic acid, naringin, hesperidin, rosmarinic acid, liquiritigenin, kaempferol, glycyrrhizin, nobiletin, 6-gingerol, elemicin, atractylenolide III, nootkatone, and atractylenolide I) in Hyangso-san using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS). Column for the separation of the 15 ingredients was used a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) at $45^{\circ}C$ by using a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile with gradient condition. Identifications of all analytes were performed using a Waters ACQUITY TQD LC-MS/MS system. The flow rate and injection volume were 0.3 mL/min and $2.0{\mu}L$, respectively. Correlation coefficient of the calibration curve was ${\geq}0.9958$. The values of limits of detection and quantification of the 15 components were 0.002-4.29 and 0.01-12.88 ng/mL, respectively. The result of an analysis using the established LC-MS/MS method, kaempferol and atractylenolide I were not detected, while other 13 compounds were 0.08-56.87 mg/g in lyophilized Hyangso-san sample.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.190-196
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• 2008

Deoxypodophyllotoxin (DPT) is a medicinal herb product isolated from Anthriscus sylvestris. DPT possesses beneficial activities in regulating immediate-type allergic reaction and anti-inflammatory activity through the dual inhibition of cyclooxygenase-2 and 5-lipoxygenase. In the present study, the metabolism of DPT was further characterized in rat liver microsomes isolated from male Sprague Dawley rats. The metabolism of DPT was NADPH-dependent. In addition, when liver microsomes were incubated with SKF-525A, a well-known CYP inhibitor, in the presence of $\beta$-NADPH, the metabolism of DPT was significantly inhibited. Using enriched rat liver microsomes, the anticipated isoforms of cytochrome P450s (CYPs) in the metabolism of DPT were partially characterized. Phenobarbital-induced microsomes increased in the formation of metabolite M1. The metabolite M3 was only produced in the enriched microsomes isolated from dexamethasone-treated rats. The results indicated that the metabolism of DPT would be CYP-dependent and that CYP2B and CYP3A might be important in the metabolism of DPT in rats.

• Natural Product Sciences
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• v.22 no.4
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• pp.238-245
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• 2016

Gumiganghwal-tang has been used for the treatment of common cold for a long-time. We developed an accurate and sensitive high performance liquid chromatography-diode array detection (HPLC-DAD) and electrospray ionization mass spectrometry method for the simultaneous determination of ferulic acid, baicalin, bergapten, methyl eugenol, glycyrrhizin, oxypeucedanin, wogonin, nodakenin, atractylenolide III, imperatorin, and atractylenolide I in Gumiganghwal-tang samples. The analytes were separated on a Shiseido C18 column ($5{\mu}m$, $4.6mm\;I.D.{\times}250mm$) with gradient elution with acetonitrile and 0.1% trifluoroacetic acid. Eleven compounds were quantitatively determined by HPLC-DAD and identified by LC-MS data. We also validated this method. The calibration curves of all the compounds showed good linear regression. The limits of detection and the limits of quantification ranged from 0.04 to 0.63 and from 0.12 to $1.92{\mu}g/mL$, respectively. The relative standard deviation values of intra- and inter-days of this method represented less than 2.9%. The recoveries were found to be in the range of 90.06 - 107.66%. The developed method has been successfully applied to the analysis of Gumiganghwaltang samples. The established HPLC method could be used to quality control of Gumiganghwal-tang.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1527-1535
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• 2018

Bacterial strain BAS23 was isolated from rice field soil and identified as Bacillus amyloliquefaciens. Based on dual culture method results, the bacterium BAS23 exhibited potent in vitro inhibitory activity on mycelial growth against a broad range of dirty panicle fungal pathogens of rice (Curvularia lunata, Fusarium semitectum and Helminthosporium oryzae). Cell-free culture of BAS23 displayed a significant effect on germ tube elongation and mycelial growth. The highest dry weight reduction (%) values of C. lunata, H. oryzae and F. semitectum were 92.7%, 75.7%, and 68.9%, respectively. Analysis of electrospray ionization-mass spectrometry (ESI-MS) and $^1H$ nuclear magnetic resonance (NMR) spectroscopy revealed that the lipopeptides were iturin A with a C14 side chain (C14 iturinic acid), and a C15 side chain (C15 iturinic acid), which were produced by BAS23 when it was cultured in nutrient broth (NB) for 72 h at $30^{\circ}C$. BAS23, the efficient antagonistic bacterium, also possessed in vitro multiple traits for plant growth promotion and improved rice seedling growth. The results indicated that BAS23 represents a useful option either for biocontrol or as a plant growth-promoting agent.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.561-570
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• 2020

This study was designed to synthesize triglycerol monolaurate (TGML) with Lipozyme 435 as the catalyst, and explore its effects on the growth of Aspergillus parasiticus (A. parasiticus) and Aspergillus flavus (A. flavus) and the secretion of aflatoxin b1. The highest content of TGML (49.76%) was obtained at a molar ratio of triglycerol to lauric acid of 1.08, a reaction temperature of 84.93℃, a reaction time of 6 h and an enzyme dosage of 1.32%. After purification by molecular distillation combined with the washes with ethyl acetate and water, the purity of TGML reached 98.3%. Through characterization by electrospray-ionization mass spectrometry, infrared spectrum and nuclear magnetic resonance, the structure of TGML was identified as a linear triglycerol combined with lauroyl at the end. Finally, the inhibitory effects of TGML on the growths of A. parasiticus and A. flavus and the secretion of aflatoxin b1 were evaluated by measuring the colony diameter, the inhibition rate of mycelial growth and the content of mycotoxin in the media. The results indicated that TGML had a stronger inhibitory effects on colony growth and mycelial development of both toxic molds compared to sodium benzoate and potassium sorbate, and the secretions of toxins from A. parasiticus and A. flavus were completely suppressed when adding TGML at 10 and 5 mM, respectively. Based on the above results, TGML may be used as a substitute for traditional antifungal agents in the food industry.

• Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.22.1-22.7
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• 2016

One of the main compounds in Ishige okamurae, diphlorethohydroxycarmalol (DPHC), is known to exhibit antiviral and anti-inflammatory effects. However, it has not been investigated extensively. In this study, preparative centrifugal partition chromatography (CPC) coupled with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) online HPLC was employed for effectively separating considerable amounts of antioxidant compounds from marine algae. Two main antioxidant compounds, DPHC and octaphlorethol A (OPA), respectively, were confirmed and isolated from the ethyl acetate (EtOAc) fraction of I. okamurae by $ABTS^+$ online HPLC and preparative CPC systems. The presence of DPHC and OPA was confirmed in the EtOAc fraction of I. okamurae by both liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI/MS) and $ABTS^+$ online HPLC systems: DPHC (39 mg) and OPA (23 mg) were successfully isolated from I. okamurae (500 mg) with optimum solvent composition (0.5:10:4:6; n-hexane/EtOAc/MeOH/water, v/v) with corresponding partition coefficients (K) of 1.62 and 2.71, respectively, by preparative CPC. Hence, CPC coupled with $ABTS^+$ online HPLC is convenient for the efficient and simple isolation of these antioxidant compounds from I. okamurae.