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Song H.-S.,Hannam University | Seo H.-I.,Hannam University | Shin C.-H.,KT and G Central Research Institute | Kim S.-J.,Hannam University
Journal of the Korean Chemical Society | Year: 2015

The DFT and ab initio calculations have been performed to elucidate hydrogen interaction of hydrogen polyoxide dimers, H2On-H2Om (n=1-4, m=1-4). The optimized geometries, harmonic vibrational frequencies, and binding energies are predicted at various levels of theory. The harmonic vibrational frequencies of the molecules considered in this study show all real numbers implying true minima. The higher-order correlation effect were discussed to compare MP2 result with CCSD(T) single point energy. The binding energies were corrected for the zero-point vibrational energy (ZPVE) and basis set superposition errors (BSSE). The largest binding energy predicted at the CCSD(T)/cc-pVTZ level of theory is 8.18 kcal/mol for H2O4-H2O3 and the binding energy of water dimer is predicted to be 3.00 kcal/mol.


Kim S.-H.,Hannam University | Shin C.-H.,KT and G Central Research Institute | Kim J.-S.,Hannam University | Kang S.-Y.,Hannam University | Kim S.-J.,Hannam University
Journal of the Korean Chemical Society | Year: 2015

The density functional theory (DFT) calculations on (H2O)n@C60, (n=1-10) complexes have been performed to elucidate hydrogen interaction between fullerene and water clusters. The optimized geometries, harmonic vibrational frequencies, and binding energies are predicted at various levels of theory. The harmonic vibrational frequencies for the molecules considered in this study show all real numbers implying true minima. We also compare the H-bond interaction between (H2O)n and (H2O)n@C60, (n=1-10) clusters.


Yim N.,Chungnam National University | Ha D.T.,Chungnam National University | Ha D.T.,National Institute of Medicinal Materials | Trung T.N.,Chungnam National University | And 7 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2010

Nine compounds isolated from the leaf and stem of Vitis amurensis Rupr. (Vitaceae) were evaluated for their antimicrobial activity against two oral pathogens, Streptococcus mutans and Streptococcus sanguis, which are associated with caries and periodontal disease, respectively. The results of several antimicrobial tests, including MIC, MBC, and TBAI, showed that three compounds inhibited the growth of the test bacteria at concentrations ranging from 12.5 to 50 μg/mL. Among these compounds, compound 5, trans-ε-viniferin, displayed the strongest activity against S. mutans and S. sanguis with MIC values of 25 and 12.5 μg/mL, respectively. This is the first report on the antimicrobial activity of stilbenes and oligostilbenes isolated from the leaf and stem of V. amurensis. Thus, this result suggests that natural antimicrobial compounds derived from V. amurensis may benefit oral health as plaque-control agents for the prevention of dental caries and periodontal disease. © 2009 Elsevier Ltd. All rights reserved.


van Dan N.,Chungnam National University | Ramchiary N.,Chungnam National University | Choi S.R.,Chungnam National University | Uhm T.S.,Chungnam National University | And 3 more authors.
Conservation Genetics | Year: 2010

Panax ginseng, commonly known as Korean ginseng, is a valued source of herbal medicine in Korea and China. We have developed and characterized 35 microsatellite markers in P. ginseng from available BAC end sequences. Characterization of these 35 SSR primer pairs in 14 cultivars of P. ginseng showed 12 primer pairs to be polymorphic and 19 primer pairs to be monomorphic, while the remaining four primer pairs did not produce any product. The number of alleles amplified ranged from 4 to 8 per primer pair, with an average of six alleles per locus. The expected and observed heterozygosities ranged from 0. 7500 to 0. 9678 and 0. 5645 to 0. 7109, respectively. None of these loci deviated from Hardy-Weinberg equilibrium. All of the functional primer pairs of P. ginseng showed cross-species transferability with Panax quinquefolium. The cross-species transferable markers could be used for ginseng cultivar identification, for genomic studies, including mapping of specific trait QTL/genes, and for measuring conservation of ginseng. © 2009 Springer Science+Business Media B.V.


Lee K.-R.,Seoul National University | Chae Y.-J.,Seoul National University | Cho S.-E.,KT and G Central Research Institute | Chung S.-J.,Seoul National University
Drug Development and Industrial Pharmacy | Year: 2011

A single-dose glass ampoule was developed for ease of administration. When glass ampoules are opened, resulting in contamination by particulate matter. Reducing its contamination may minimize the risk in patients due to particulates. This study reports on an attempt to reduce insoluble particulate contamination by developing methods for the precise measurement of this. A vacuum machine (VM) was used to reduce the level of insoluble particulate contamination, and a microscopy, scanning electron microscopy-energy dispersive X-ray spectrometer (SEM-EDS) and inductively coupled plasma-atomic emission spectrometer (ICP-AES) were used to evaluate the level of reduction. The method permitted the insoluble particle content to be reduced by up to 87.8 and 89.3% after opening 1 and 2 mL-ampoules, respectively. The morphology of the glass particulate contaminants was very sharp and rough, a condition that can be harmful to human health. The total weight of glass particles in the opened ampoules was determined to be 104±72.9 g and 30.5±1.00 g after opening 1 and 2 mL-ampoules when the VM was operated at highest power. The total weights were reduced to 53.6 and 50.6%, respectively for 1 and 2 mL-ampoules, compared to opening by hand. The loss of ampoule contents on opening by the VM was 6.50 and 4.67% for 1 and 2 mL-ampoules, respectively. As a result, the VM efficiently reduced glass particulate contamination and the evaluation methods used were appropriate for quantifying these levels of contamination. © 2011 Informa Healthcare USA, Inc.


Kim Y.-S.,Chonbuk National University | Song J.-G.,Chonbuk National University | Lee I.-K.,Chonbuk National University | Yeo W.-H.,KT and G Central Research Institute | Yun B.-S.,Chonbuk National University
Mycobiology | Year: 2013

A Bacillus sp. BS061 significantly reduced disease incidence of gray mold and powdery mildew. To identify the active principle, the culture filtrate was partitioned between butanol and water. The antifungal activity against B. cinerea was evident in the butanol-soluble portion, and active substances were identified as cyclic lipopeptides, iturin A series, by nuclear magnetic resonance spectrometry (NMR) and mass analysis. Interestingly, antifungal activity against powdery mildew was observed in the water-soluble portion, suggesting that cyclic lipopeptides have no responsibility to suppress powdery mildew. This finding reveals that biocontrol agents of Bacillus origin suppress gray mold and powdery mildew through the secretion of different bioactive substances. © The Korean Society of Mycology.


Kim Y.-S.,Chonbuk National University | Song J.-G.,Chonbuk National University | Lee I.-K.,Chonbuk National University | Yeo W.-H.,KT and G Central Research Institute | Yun B.-S.,Chonbuk National University
Mycobiology | Year: 2013

The use of a microorganism, or its secretions, to prevent plant disease offers an attractive alternative or supplement to synthetic fungicides for the management of plant disease without the negative effects of chemical control mechanisms. During a screening for microorganisms with the potential to be used as microbial fungicides, Bacillus sp. BS061 was isolated from a plant leaf. The strain BS061 potently inhibited the mycelial growth of Botrytis cinerea, and significantly reduced disease incidence of powdery mildew in cucumber and strawberry. We also found that the culture filtrate of BS061 inhibited the mycelial growth of various plant pathogens. © The Korean Society of Mycology.


Choi D.-Y.,Chungbuk National University | Lee J.W.,Chungbuk National University | Peng J.,Chungbuk National University | Lee Y.J.,Chungbuk National University | And 10 more authors.
Journal of Neurochemistry | Year: 2012

Etiology of Alzheimer's disease (AD) is obscure, but neuroinflammation and accumulation of β-amyloid (Ab) are implicated in pathogenesis of AD. We have shown anti-inflammatory and neurotrophic properties of obovatol, a biphenolic compound isolated from Magnolia obovata. In this study, we examined the effect of obovatol on cognitive deficits in two separate AD models: (i) mice that received intracerebroventricular (i.c.v.) infusion of Aβ 1-42 (2.0 μg/mouse) and (ii) Tg2576 mice-expressing mutant human amyloid precursor protein (K670N, M671L). Injection of Aβ 1-42 into lateral ventricle caused memory impairments in the Morris water maze and passive avoidance tasks, being associated with neuroinflammation. Aβ 1-42-induced abnormality was significantly attenuated by administration of obovatol. When we analyzed with Tg2576 mice, long-term treatment of obovatol (1 mg/kg/ day for 3 months) significantly improved cognitive function. In parallel with the improvement, treatment suppressed astroglial activation, BACE1 expression and NF-κB activity in the transgenic mice. Furthermore, obovatol potently inhibited fibrillation of Aβ in vitro in a dose-dependent manner, as determined by Thioflavin T fluorescence and electron microscopic analysis. In conclusion, our data demonstrated that obovatol prevented memory impairments in experimental AD models, which could be attributable to amelioration of neuroinflammation and amyloidogenesis by inhibition of NF-κB signaling pathway and anti-fibrillogenic activity of obovatol. © 2011 The Authors Journal of Neurochemistry © 2011 International Society for Neurochemistry.


Kim D.-H.,Korea Research Institute of Standards and Science | Chang J.-K.,KT and G Central Research Institute | Sohn H.-J.,KT and G Central Research Institute | Cho B.-G.,KT and G Central Research Institute | And 4 more authors.
Accreditation and Quality Assurance | Year: 2010

A pure certified reference material (CRM) for the ginsenoside Rg1 was prepared from roots of Panax ginseng by extraction and separation of ginsenosides. The mass fraction of the main component (ginsenoside Rg1) in the reference material was determined and its uncertainty was assessed from various input quantities, such as organic impurities, residual moisture, residual solvent, ash, and insoluble matters. To measure these input quantities, HPLC/CAD, Karl Fischer (KF) coulometry, gravimetry, and GC/FID were used. Homogeneity and long-term stability of the reference material are discussed. The certified mass fraction of Rg1 in the reference material is 0.974 ± 0.006 (k = 2) with a shelf life of 1 year. © Springer-Verlag 2009.


Lee S.M.,KT and G Central Research Institute
Food Chemistry | Year: 2010

Two new conversion ginsenosides having cyclic ether together with ginsenoside Rg5, Rk1, and Rz1 were isolated from dehydration products of 20(S)-ginsenoside Rg3. On the basis of NMR spectroscopic analyses and comparison with spectral data of ginsenoside Rg3 as a starting material, the chemical structures of two new ginsenosides were established as 12β-O-20(S)-ginsenoside Rg3 and 12β-O-20(R)-ginsenoside Rg3. The compounds were named as neoginsenoside L1 and L2 respectively. The conversion mechanism was expected to be accomplished by the formation of a tertiary carbocation or intramolecular nucleophilic displacement. The two new ginsenosides confirmed the existence from red ginseng extract by liquid chromatography. © 2009 Elsevier Ltd. All rights reserved.

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