• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.244-249
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• 2011

A sensitive and rapid high-performance liquid chromatographic-tandem mass spectrometric (HPLC/MS/MS) assay was developed for the determination of soyasaponins in soybean. Among soyasaponins, soyasaponin I was isolated and characterized from methanol extracts of soybean as analytical standards and the development of a new analytical procedure for quantification of its content in various cultivars. The structures of these compound was elucidated by $^1H$, $^{13}C$ NMR experiments and by mass spectrometric analysis. Aqueous ethanol extracts of soybean samples were injected on an Agilent XDB-C18 column ($4.6mm{\times}50mm$, $1.8{\mu}m$) with a mobile phase consisting of 10 mM ammonium acetate-acetonitrile, a flow rate of 0.3 mL/min and a total run time of 8 min. Detection was performed by mass spectrometer bin the multiple reaction monitoring (MRM) mode with negative electrospray ionization (ESI) m/z at 941 ${\rightarrow}$ 615 for soyasaponin I. In the 9 soybean samples, contents of soyasaponin I ranged from 205 to 726 mg/kg, and correlated negatively with seed size.

• Mass Spectrometry Letters
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• v.12 no.1
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• pp.1-10
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• 2021

A simple, specific, and economical LC-MS/MS method was investigated for the screening of 43 prescribed antihypertensive and related drugs in human urine. The urine samples were simply prepared by diluting and mixing with internal standard before directly introduced to the LC-MS/MS system, which is fast, straightforward, and cost-effective. Fractional factorial, Box-Behnken, and I-optimal design were applied to screen and optimize the mass spectrometric and chromatographic factors. The analysis was carried out on a triple quadrupole mass spectrometer system utilizing multiple reaction monitoring with positive and negative electrospray ionization method. Chromatographic separation was performed on a Thermo Scientific Accucore RP-MS column (50 × 3.0 mm ID., 2.6 ㎛) using two separate gradient elution programs established with the same mobile phases. Chromatographic separation was performed within 12 min. The optimal method was validated based on FDA guideline. The results indicated that the assay was specific, reproducible, and sensitive with the limit of detection from 0.1 to 50.0 ㎍/L. The method was linear for all analytes with coefficient of determination ranging from 0.9870 to 0.9981. The intra-assay precision was from 1.44 to 19.87% and the inter-assay precision was between 2.69 and 18.54% with the recovery rate ranges from 84.54 to 119.78% for all drugs measured. All analytes in urine samples were stable for 24 h at 25℃, and for 2 weeks at -60℃. The developed method improves on currently existing methods by including larger number of cardiovascular medications and better sensitivity of 12 analytes.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.109-115
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• 2019

Objective : Herbal medicinal mixture (JMB) are consisted of Caryophylli Flos, Aucklandiae Radix, and Angelicae Dahuricae Radix. Each of these herbal medicines has studied on anti-aging effect in vitro. So this study was conducted to investigate efficacy and potency of JMB extract on dermal anti-aging and whitening. Methods : The JMB was extracted at room temperature by 80% ethanol. Collagenase and elastase inhibition activity in JMB ethanol extract were determined at 10, 50, 100, 500, 1000 mg/ml concentrations by colorimetric method. The toxic range of JMB ethanol extract was evaluated using MTT assay. Also, The inhibitory effect of JMB ethanol extract on tyrosinase activity and melanin contents in mouse melanoma cell line (B16F10 cell) was identified at 50, 100, 200 ㎍/㎖ levels by spectrometric assay. In each analysis, EGCG (epigallocatechin gallate) and Kojic acid were used as positive controls, respectively. Results : The elastase and collagenase inhibitory activity of JMB ethanol extract increased dose dependently. Also, The MTT assay showed that JMB, up to 400 ㎍/㎖ concentration, exhibited no toxic effect to the B16F10 cell. And following the JMB ethanol extract treat, cellular melanin contents and tyrosinase activity were dose-dependently decreased compared to those of control. Conclusion : These results suggest that JMB ethanol extract has effects to inhibitory activity on dermal wrinkle enzyme and melanogenesis. Therefore, JMB has applicable benefits for development of materials or products to have whitening and anti-aging functions on skin.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.409-416
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• 2017

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of $6.92{\pm}0.09$. It has spreadability value of $15.04{\pm}0.98g{\cdot}cm/sec$ and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control $Kwell^{(R)}$, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.196-200
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• 2003

A gas chromatography/mass spectrometric assay method was developed for the simultaneous determination of ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethyl ether (DEGME) in spilled aviation fuels. Ethylene glycol monobutyl ether (EGBE) and ethylene glycol monoethyl ether (EGEE) were used as internal standard and surrogate, respectively. The sample preparation consists of back-extraction with 7 mL of methylene chloride after extraction of 50 mL of fuel with 2 mL of water. The extract was concentrated to dryness and dissolved with 100L of methanol and analyzed by CC-MS (SIM). The peaks had good chromatographic properties by using semi-polar column and the extraction of these compounds from fuel also gave high recoveries of 75 and 85 % with small variations for EGME and DEGME, respectively. Method detection limits were 1.3 ng/mL for EGME and 1.0 ng/mL for DEGME in spilled fuel. The method may be useful for fuel-type differentiation between kerosene and JP-8, which may originate from the storage tank.

• YAKHAK HOEJI
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• v.47 no.3
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• pp.142-147
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• 2003

Gas chromatography-mass spectrometric (GC-MS) procedure is presented for the simultaneous qualification and quantitation of methamphetamine (MA), amphetamine (AMP), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), and 3,4-methylenedioxyethylamphetamine (MDEA) in human hair. The method procedure involves decontamination of hair with distilled water and acetone, acidic hydrolysis, extraction in the presence of deuterated internal standards, and GC-MS analysis after derivatization with trifluoroacetic anhydride (TFAA) in ethylacetate. The limit of detection for 5 drugs were about 0.1∼0.15 ng/mg using 30 mg hair sample. Coefficient variations of correlation ranged from 0.9941 to 0.9993. The recoveries of these drugs were found to be 93.4∼104.4％. The concentrations of AMP, MA, MDA, and MDMA in abusers' hair samples were measured 0.17∼2.88, 2.09∼18.34, 0.24∼3.83, and 3.10∼22.81 ng/mg, respectively. The ratios of MA/AMP and MDMA/MDA ranged 5.67∼49.57 and 4.78∼54.31, respectively. This assay has been successfully utilized in the evaluation of the deposition of amphetamine-type stimulants (ATS) in human hair.

• YAKHAK HOEJI
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• v.47 no.3
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• pp.184-189
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• 2003

Peptide deformylase (PDF) is essential and unique to bacteria, thus making it an attractive target for the discovery of novel antibacterial drugs. PDF deformylates the N-formylmethionine of newly synthesized polypeptides in prokaryotes. In this study, a pdf gene from Staphylococcus aureus 6538p was cloned in pET-14b vector and PDF protein was over-produced in Escherichia coli BL21 (DE3). NH$_2$-terminal His-tagged PDF protein was purified by nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography. Enzymatic activity of purified 6xHis-tagged PDF was tested on the substrate (formyl-Methionine-Alanine-Serine) by formate dehydrogenase-coupled spectrometric assay of peptide deformylase. For the discovery of new PDF inhibitors from chemical libraries and culture broths of soil bacteria, a target-oriented screening system using a 96-well plate was developed. About 3,000 commercial chemical libraries were tested in this screening system, and 2 chemicals (0.07％) among them showed an inhibitory activity against PDF enzyme. This result showed that a new screening system can be used for the discovery of new PDF inhibitors.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1489-1494
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• 2004

A gas chromatography/mass spectrometric assay method was developed for the determination of persistent organochlorine pollutants (POPs) in hair. For the exact extraction study was used hair of rat exposed with POPs. Sonication of the hair matrix with 3 M HCl solution in methylene chloride of the extraction methods studied was the most efficient and rapid sample preparation method. After sonication of rat hair was achieved clean up with a solid phase extraction procedure using silica gel-florisil. Elution was performed with 8 mL of methylene chloride. The eluate was concentrated to approximately 100 ${\mu}L$ and analyzed by gas chromatography-mass spectrometry (GC-MS). Detection limits of POPs were in the concentration range of 0.6-1.2 ng/g in rat hair. Aldrin, dieldrin, p,p-DDT and mirex were dosed rat for 4 weeks at concentration of 0.01 mg/L in drinking water and detected in rat hair at concentration of 2.8, 11.3, 7.9 and 15.6 ng/g, respectively. Aldrin and p,p-DDT were metabolized to dieldrin and p,p-DDE, which were detected in concentration of 9.7 and 2.9 ng/g in rat hair, respectively. The developed method may be valuable to be used to analyze POPs in human hair.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.44-52
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• 2006

New organotin(IV) derivatives with general formulae R_2SnL_2 and R_3SnL, where R = methyl, n-butyl, n-octyl and phenyl and HL is either 3-[N-(4-nitrophenyl)amido]-propenoic acid or 3-[N-(4-nitrophenyl)amido] propanoic acid have been synthesized in 1 : 2 and 1 : 1 molar ratio by different methods. The FTIR spectra clearly demonstrated that the organotin(IV) moieties react with [O,O] atoms of the ligands. The bonding and coordination behavior in these complexes are discussed on the basis of multinuclear (^1H,\,^{13}C,\,^{119}Sn) NMR and mass spectrometric studies. Antibacterial, and antifungal screening tests were performed for these compounds and reported here. These values were compared to those of the precursors and it was found that diorganotin(IV) complexes exhibit less activity as compared to triorganotin(IV) complexes . LD_{50} data were obtained by Brine Shrimp assay method. Insecticidal activity was performed for selective compounds by contact toxicity method.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.570-575
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• 2014

This study was conducted to compare the effects of two forms of radiation (electron and X-ray; generated by an electron beam accelerator) on the conformation and antigenic properties of hen's egg albumin, ovalbumin (OVA), which was used as a model protein. OVA solutions (2.0 mg/mL) were individually irradiated by electron beam or X-ray at the absorbed doses of 0 (control), 2, 4, 6, 8, and 10 kGy. No differences between the two forms of radiation on the structural properties of OVA were shown by spectrometric and electrophoretic analyses. The turbidity of OVA solution increased and the main OVA bands on polyacrylamide gels disappeared after irradiation, regardless of the radiation source. In competitive indirect enzyme-linked immunosorbent assay, OVA samples irradiated by electron beam or X-ray showed different immunological responses in reactions with monoclonal and polyclonal antibodies (immunoglobulin G) produced against non-irradiated OVA. The results indicate that electron beam irradiation and X-ray irradiation produced different patterns of structural changes to the OVA molecule.