• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3285-3292
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• 2012

The interaction of thiazole drug with (6,0) zigzag single-walled boron nitride nanotube of finite length in gas and solvent phases was studied by means of density functional theory (DFT) calculations. In both phases, the binding energy is negative and presenting characterizes an exothermic process. Also, the binding energy in solvent phase is more than that the gas phase. Binding energy corresponding to adsorption of thiazole on the BNNT model in the gas and solvent phases was calculated to be -0.34 and -0.56 eV, and about 0.04 and 0.06 electrons is transferred from the thiazole to the nanotube in the phases. The significantly changes in binding energies and energy gap values by the thiazole adsorption, shows the high sensitivity of the electronic properties of BNNT towards the adsorption of the thiazole molecule. Frontier molecular orbital theory (FMO) and structural analyses show that the low energy level of LUMO, electron density, and length of the surrounding bonds of adsorbing atoms help to the thiazole adsorption on the nanotube. Decrease in global hardness, energy gap and ionization potential is due to the adsorption of the thiazole, and consequently, in the both phases, stability of the thiazole-attached (6,0) BNNT model is decreased and its reactivity increased. Presence of polar solvent increases the electron donor of the thiazole and the electrophilicity of the complex. This study may provide new insight to the development of functionalized boron nitride nanotubes as drug delivery systems for virtual applications.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.41-48
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• 2012

Introduction: Breast cancer is the second leading cancer in Korean women. To assess potential genetic associations between the prostate stem cell antigen (PSCA) gene in the chromosome 8q24 locus and breast cancer risk in Korean women, 13 SNPs were selected and associations with breast cancer risk were analyzed with reference to hormone receptor (HR) and menopausal status. Methods:We analyzed DNA extracted from buffy coat from 456 patients and 461 control samples, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) based upon region-specific PCR followed by allelespecific single base primer extension reactions. Risks associated with PSCA genotypes and haplotypes were estimated with chi-square test (${\chi}^2$-test), and polytomous logistic regression models using odds ratios (OR) and 95% confidence intervals (CIs), by HR and menopausal status. Results: In case-control analysis, odds ratios (OR) of rs2294009, rs2294008, rs2978981, rs2920298, rs2976395, and rs2976396 were statistically significant only among women with estrogen receptor (ER) negative cancers, and those of rs2294008, rs2978981, rs2294010, rs2920298, rs2976394, rs10216533, and rs2976396 were statistically significant only in pre-menopausal women, and not in postmenopausal women. Risk with the TTGGCAA haplotype was significantly elevated in ER (-) status (OR= 1.48, 95% CI= 1.03~2.12, p<0.05). Especially risk of allele T of rs2294008 is significantly low in pre-menopausal breast cancer patients and AA genotype of rs2976395 in ER (-) status represents the increase of OR value. Conclusion: This report indicated for the first time that associations exist between PSCA SNPs and breast cancer susceptibility in Korean women, particularly those who are pre-menopausal with an estrogen receptor negative tumor status.

• Mycobiology
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• v.45 no.1
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• pp.44-47
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• 2017

Ginseng damping-off, caused by the fungal pathogens Rhizoctonia solani and Pythium sp., is a critical disease in ginseng seedling. In a continuing effort to find microorganisms with the potential of acting as a biocontrol agent against Rhizoctonia damping-off, we found that a Streptomyces sp. A501 showed significant antifungal activity against Rhizoctonia solani. In field experiment to test the efficacy of Streptomyces sp. A501 in controlling ginseng damping-off, the incidence of damping-off disease was meaningfully reduced when ginseng seeds were soaked in the culture broth of Streptomyces sp. A501 before sowing. To perform characterization of the antifungal compound, we isolated it from the culture broth of strain A501 through Diaion HP-20 and silica gel column chromatographies and preparative high-performance liquid chromatography. The structure of the antifungal compound was assigned as fungichromin by spectroscopic methods, mainly nuclear magnetic resonance and electrospray ionization-mass analysis.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.738-747
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• 2015

Angiotensin-converting enzyme (ACE) inhibitory activity was evaluated for the low-molecular-weight fraction (<3 kDa) obtained from milk fermentation by Bifidobacterium longum KACC91563. The ACE inhibitory activity in this fraction was 62.3%. The peptides generated from the <3 kDa fraction were identified by liquid chromatography-electrospray ionization quantitative time-of-flight mass spectrometry analysis. Of the 28 peptides identified, 11 and 16 were identified as β-casein (CN) and α_s1-CN, respectively. One peptide was identified as κ-CN. Three peptides, YQEPVLGPVRGPFPIIV, QEPVLGPVRGPFPIIV, and GPVRGPFPIIV, from β-CN corresponded to known antihypertensive peptides. We also found 15 peptides that were identified as potential antihypertensive peptides because they included a known antihypertensive peptide fragment. These peptides were as follows: RELEELNVPGEIVE (f1-14), YQEPVLGPVRGPFP (f193-206), EPVLGPVRGPFPIIV (f195-206), PVLGPVRGPFPIIV (f196-206), VLGPVRGPFPIIV (f197-206), and LGPVRGPFPIIV (f198-206) for β-CN; and APSFSDIPNPIGSENSEKTTMPLW (f176-199), SFSDIPNPIGSENSEKT- TMPLW (f178-199), FSDIPNPIGSENSEKTTMPLW (f179-199), SDIPNPIGSENSEKTTMPLW (f180-199), DIPNPIGSENSEKTTMPLW (f181-199), IPNPIGSENSEKTTMPLW (f182-199), PIGSENSEKTTMPLW (f185-199), IGSENSEKTTMPLW (f186-199), and SENSEKTTMPLW (f188-199) for α_s1-CN. From these results, B. longum could be used as a starter culture in combination with other lactic acid bacteria in the dairy industry, and/or these peptides could be used in functional food manufacturing as additives for the development of a product with beneficial effects for human health.

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.1933-1938
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• 2009

New $\pi$-conjugated polymer with vinylene linkage, poly((10-hexyl-3,7-phenothiazine)-alt-(4-(4-butyl-phenyl)- 3,5-diphenyl-4H-[1,2,4]triazole)-3,5-vinylene) (PTV-TAZ) was synthesized by the Heck coupling reaction. The photoluminescence (PL) maximum wavelength and the band gap energy of PTV-TAZ film were 555 nm and 2.41 eV, respectively. The HOMO energy level of PTV-TAZ was -4.99 eV, which was slightly lower than that of PTV (-4.89 eV). Electron deficient aromatic 1,2,4-triazole (TAZ) in the polymer backbone does not affect the HOMO energy level significantly. The maximum efficiency and brightness of double layer structured electroluminescent (EL) device (ITO/PEDOT (30 nm)/PTV-TAZ (60 nm)/Al) were 0.247 cd/A and 553 cd/$m^2$, respectively, which were significantly higher than those of the device based PTV (1.65 ${\times}\;10^{-4}$ cd/A and 4.3 cd/$m^2$). This is due to that TAZ unit improves electron transporting ability in the emissive layer. The turn-on voltage (defined as the voltage required to give a luminescence of 1 cd/$m^2$) of brightness of the device based on PTV-TAZ was 12.0 V, which was similar to that the based on PTV (11.5 V). This is due to that the ionization potential of PTV-TAZ is very similar to that of PTV.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1097-1101
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• 2008

The objective of this study was to identify and quantify glucosinolates (GSLs) in Brassica napus cv. Hanakkori and its parents and to evaluate its potential bitter taste. 'Hanakkori' materials were cultivated with commercial chemical nutrients (20 kg/ha, N-P-K: 16-10-10) at the field. GSLs were isolated by means of extraction with 70%(v/v) boiling methanol (MeOH) followed by desulfation from those plants by reversed-phase high performance liquid chromatography (HPLC) and identified by electronic spray ionization-mass spectrometry (ESI-MS) analysis. In 'Hanakkori', 11 GSLs were identified as progoitrin, glucoraphanin, glucoalyssin, gluconapoleiferin, gluconapin, 1-methylpropyl, glucobrassicanapin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin. The total GSL contents were 109 and 36.1 mmol/kg dry weights (d.w.) for the seeds and edible parts, respectively. The major GSLs (>5 mmol/kg d.w.) in the seeds were progoitrin (78.8), gluconapin (10.7), and glucobrassicanapin (7.81), whereas they in the edible parts were progoitrin (16.1) and glucobrassicanapin (8.58). In addition, the bitter taste in the edible parts was presumably related with the presence of progoitrin (>45% to the total GSL).

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.263-263
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• 2013

This work examines the dynamic properties of ice surfaces in vacuum for the temperature range of 140~180 K, which extends over the onset temperatures for ice sublimation and the phase transition from amorphous to crystallization ice. In particular, the study focuses on the transport processes of excess protons and chloride ions in ice and their segregative behavior to the ice surface. These phenomena were studied by conducting experiments with a relatively thick (~100 BL) ice film constructed with a bottom $H_2O$ layer and an upper $D_2O$ layer, with excess hydronium and chloride ions trapped at the $H_2O$/$D_2O$ interface as they were generated by the ionization of hydrogen chloride. The migration of protons, chloride ions, and water molecules to the ice film surface and their H/D exchange reactions were measured as a function of temperature using the methods of low energy sputtering (LES) and Cs+ reactive ion scattering (RIS). Temperature programmed desorption (TPD) experiments monitored the desorption of water and hydrogen chloride from the surface. Our observations indicated that both hydronium and chloride ions migrated from the interfacial layer to segregate to the surface at high temperature. Hydrogen chloride gas desorbs via recombination reaction of hydronium and chloride ions floating on the surface. Surface segregation of these species is driven by thermodynamic potential gradient present near the ice surface, whereas in the bulk, their transport is facilitated by thermal diffusion process. The finding suggests that chlorine activation reactions of hydrogen chloride for polar stratospheric ice particles occur at the surface of ice within a depth of at most a few molecular layers, rather than in the bulk phase.

• Environmental Engineering Research
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• v.18 no.3
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• pp.169-176
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• 2013

The present study was designed to examine the concentrations, emission rates, and source characteristics of a variety of volatile organic compounds (VOCs) in 30 newly-constructed apartment buildings by measuring indoor and outdoor VOC concentrations over a 2-year period. For comparison, seven villa-type houses were also surveyed for indoor and outdoor VOC concentrations over a 3-month period. Indoor and outdoor air samples were collected on Tenax-TA adsorbent and analyzed using a gas chromatograph (GC)/mass spectrometer system or a GC/flame ionization detector system coupled to a thermal desorption system. The long-term change in indoor VOC concentrations depended on the type of VOCs. Generally, aromatic (except for naphthalene), aliphatic, and terpene compounds exhibited a gradual deceasing trend over the 2-year follow-up period. However, the indoor concentrations of the six halogenated VOCs did not significantly vary with time changes. Similar to these halogenated VOCs, the indoor naphthalene concentrations did not vary significantly with time changes over the 2-year period. Unlike the halogenated VOCs, the indoor naphthalene concentrations were much higher than the outdoor concentrations. The indoor concentrations of aliphatic and aromatic compounds were higher for the villa-type houses when compared to those of apartment buildings. In addition, four source groups (floor coverings and interior painting, household products, wood paneling and furniture, moth repellents) and three source groups (floor coverings and interior painting, household products, and moth repellents) were considered as potential VOC sources inside apartment buildings for the first- and second-year post-occupancy stages, respectively.

• YAKHAK HOEJI
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• v.57 no.3
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• pp.194-198
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• 2013

In the present study we evaluated drug-drug interaction potential of ambroxol and cetirizine mediated by inhibition of CYP isoforms including CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4 using pooled human liver microsomes (HLMs). As measured by liquid chromatography-electrospray ionization tandem mass spectrometry, cetirizine and ambroxol inhibited significantly CYP2E1 but the maximal inhibition was approximately 36% at 10 ${\mu}M$ cetirizine and 28% at 3 ${\mu}M$ ambroxol. In addition, CYP2D6 activity was decreased to approximately 83% of control activity in pooled HLM incubated with 3 ${\mu}M$ ambroxol. Activities of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, and CYP3A4 were not significantly inhibited by cetirizine and ambroxol. Considering their maximal plasma concentration in human ($C_{max}$ of cetirizine is approximately 0.67 ${\mu}M$ and $C_{max}$ of ambroxol is 0.044 ${\mu}M$), these two drugs have very low possibility in drug-drug interaction by CYP inhibition in clinical situations.

• Herbal Formula Science
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• v.21 no.1
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• pp.177-185
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• 2013

Objectives : Leejung-tang (Lizhong-tang) has been used for treatment of gastrointestinal disorders in Korea. In this study, we performed quantification analysis of five marker components, liquiritin, ginsenoside Rb1, ginsenoside Rg1, glycyrrhizin, and 6-gingerol in Leejung-tang using a ultra performance liquid chromatography- electrospray ionization-mass spectrometer (UPLC-ESI-MS). In addition, we evaluated antioxidant activity of Leejung- tang. Methods : The column for separation of five constituents used a UPLC BEH C18 ($100{\times}2.1mm$, $1.7{\mu}m$) maintained at $45^{\circ}C$. The mobile phase consisted of two solvent systems, 0.1% (v/v) formic acid in H2O (A) and CH3CN (B) by gradient flow. The flow rate was 0.3 mL/min with detection at mass spectrometer. The antioxidative activities conduct an experiment on 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of Leejung-tang. Results : Calibration curves of five marker compounds were acquired with r2 values > 0.99. The amount of the five compounds in Leejung-tang were 0.07 - 0.84 mg/g. The concentration required for 50% reduction (RC50) against ABTS radical was 119.02 ug/mL. In addition, the scavenging against DPPH radical of Leejung-tang was 11.4%, 14.5%, 19.8%, 29.6%, and 49.2% at 25 ug/mL, $50{\mu}g/mL$, $100{\mu}g/mL$, $200{\mu}g/mL$, and $400{\mu}g/mL$, respectively. Conclusions : The established LC-MS/MS method will be helpful to improve quality control of Leejung-tang. In addition, Leejung-tang is a potential antioxidant therapeutic agent.