• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.165-172
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• 2015

The objective of this study was to investigate the antioxidant and antiobesity activities of various color resources extracted from natural plants such as, clove, persimmon, gall nut, amur cork, gardenia, safflower, and annatto. Total phenolic content was the highest in gall nut extract (2,441.45 mg/kg) followed by clove extract (1,346.48 mg/kg). DPPH, and ABTS radical scavenging activities and ferric reducing antioxidant power (FRAP) were also higher in gall nut extract. ${\alpha}$-Glucosidase inhibitory activity ($IC_{50}$) was highest in persimmon extract ($22.83{\mu}g/mL$) followed by gall nut extract. ${\alpha}$-Amylase and lipase inhibitory activities were also higher in persimmon extract (49.45% and 61.01%, respectively). Lipid accumulation in 3T3-L1 cells was lower in persimmon, clove, and annatto extracts (81.54%, 83.36%, and 85.70% at $20{\mu}g/mL$, respectively). Triglyceride content in 3T3-L1 cells was lowest in clove extract (66.11%) followed by persimmon extract (88.88%). The results of this study suggest that gall nut extract has the highest antioxidant activity, whereas persimmon and clove extract show the antiobesity activities by inhibition of digestive enzymes and fat accumulation in 3T3-L1 cells. These extracts are useful materials for the development of antioxidant and antiobesity functional foods.

• Ocean and Polar Research
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• v.28 no.3
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• pp.317-329
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• 2006

To assess the contamination status of organochlorine pesticides in the marine environment of Saemangeum, surface seawater and sediments were collected and analyzed. Organochlorine pesticides were widely distributed in the Saemangeum environment, with DDT, HCH and endosulfan II contamination being particularly prevalent. The overall concentrations of DDTs, HCHs, and endosulfan II in surface seawater were in the rage of 0.03-0.65ng/l (mean value: 0.36ng/l), 1.31-4.54ng/l (2.63 ng/l), and not detected (ND)-0.96ng/l (0.49ng/l), respectively. Among the target organochlorine pesticides, endosulfan II showed the hi띤est level at the river mouth flowing into the Saemangeum. Additionally, its negative gradient from the rivers to the outside and a good correlation with $NO_3^-$ indicate that endosulfan ll inflows to the Saemangeum through the river; this conclusion is also supported by the elevated levels of endosulfan II in sediments at the river mouth. In sediment, the concentration of DDTs, HCHs, CHLs, and endosulfan II were in the range of 0.05-1.96 ng/g, 0.03-0.31ng/g, 0.01-0.13ng/g, and ND-0.62ng/g, respectively. Levels of contamination in Saemangeum are relatively lower than the median concentrations previously observed at the Korean coastal regions and sediment quality guidelines suggested by NOAA (Long et at. 1995).

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.143-152
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• 2013

Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the central nervous system of animals, has several physiological effects including anti-hypertensive, diuretic, tranquilizing, and anti-stress properties, in humans. The purpose of this study was to investigate Lactobacillus plantarum K74, which was isolated from kimchi and selected as a strain with a high ability to produce GABA, to develop a new starter culture for fermented milk production. L. plantarum K74 produced $134.52{\mu}g/mL$ GABA in MRS broth containing 1% MSG, $212.27{\mu}g/mL$ GABA in MRS broth containing 2% MSG, and $234.63{\mu}g/mL$ GABA in MRS broth containing 3% MSG. The optimum growth temperature of L. plantarum K74 was $34^{\circ}C$, reaching a pH of 4.4 after 18 hours of growth. L. plantarum K74 was most sensitive to novobiocin out of 16 different antibiotics tested, and was most resistant to kanamycin and polymyxin B. L. plantarum K74 did not produce ${\beta}$-glucuronidase, a carcinogenic enzyme, and was comparatively tolerant to bile juice and low pH. Furthermore, it displayed resistance to Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus at rates of 54.9%, 46.3%, and 0.7%, respectively.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.269-274
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• 2018

In the middle of May 2018, typical red thread disease symptoms were observed on Kentucky bluegrass (Poa pratensis L.) on a golf course, which locates at Yangsan, Gyeongnam province in Korea. Irregular-shaped patched symptoms were observed in fairway of golf course. The foliar symptom was dried out and faded to straw color and tip of the grass leaves were tangled like thread. Early morning, infected and tangled leaves were covered with the pinkish gelatinous antler-like structure (sclerotinia) as a typical red thread disease symptom. Causal fungal pathogens were isolated from the symptom in Kentucky bluegrass. The fungal culture characteristic on potato dextrose agar color of colony was pale pink and conjugated hyphae, sclerotium of irregular shape was pale pink and 3~5mm diameter in size. The pathogen was identified as Laetisaria fuciformis based on morphological and culture characteristics as well as molecular characteristics. Pathogenicity test was verified on the Kentucky bluegrass by Koch's postulates. This is the first report of red thread disease occurrence in Kentucky bluegrass by L. fuciformis in Korea.

• Bulletin of the Korean Chemical Society
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• v.7 no.4
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• pp.304-308
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• 1986

When the two conjugated poly-ynes, 1-phenyl-6-methyl- and 1,6-diphenyl-1,3,5-hexatriynes, were irradiated with UVA in deaerated 2,3-dimethyl-2-butene solution, 1:2 photoadducts, 1-(1'-phenylethynyl-2',2',3',3'-tetramethylcyclopr opyl)-2-(l",2",2",3",3"-pentamethylcyclopropyl) acetylene and 1-(1'-phenylethynyl-2',2',3',3'-tetramethylcyclopr opyl)-2-(1"-phenyl-2",2",3",3"-tetramethylcyclopropyl) acetylene, were obtained, respectively. No photoadduct was formed with aerated 2,3-dimethyl-2-butene, or deaerated solutions of dimethyl fumarate, methyl crotonate, dimethyl maleate, and trans-1,2-dichloroethylene. The results suggest that the reactions proceed from the triplet state only with electron rich olefins such as 2,3-dimethyl-2-butene.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3707-3710
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• 2010

A chromo/fluorogenic $NO_2S_2$-macrocycle L functionalized with nitrobenzofurazan unit as a dual-signaling probe was synthesized and structurally characterized by single crystal X-ray analysis. In a cation-induced color change experiment, L exhibited excellent $Hg^{2+}$ ion selectivity by showing the color change from orange-red to yellow. However, this hypochromic shift by $Hg^{2+}$ was observed for the weaker coordinating anion system such as ${NO_3}^-$ and ${ClO_4}^-$ ions. The observed anion effect is due to the strong coordination of anions inhibits the bond formation between $Hg^{2+}$ and the macrocyclic tert-N atom, which is sensitive to induce the color change. In the fluorometric experiment, L showed chelate-enhanced fluorescence change effect only with $Hg^{2+}$ ion, together with a change from yellow to green emission. The sensing ability for $Hg^{2+}$ with the proposed chemosensor L is due to the stable complexation with 1:1 stoichiometry (metal-to-ligand).

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.265-273
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• 2019

This study aimed to evaluate the anti-atherosclerotic and anti-hypertensive effects of six different plant extracts using a N(G)-nitro-L-arginine-methyl ester (L-NAME)-induced rat model of hypertension. All extracts were administered orally for six weeks. At the end of the study period blood pressure, blood flow, aortic histopathology, and hepatic endothelial nitric oxide synthase (eNOS) expression were measured. Subsequently, we also measured the levels of intracellular reactive oxygen species, nitric oxide (NO), and anti-inflammatory cytokines in vitro. Based on these screening results, we selected extracts of Cinnamomum cassia (C. cassia) and Salvia miltiorrhiza (S. miltiorrhiza) for further evaluation. C. cassia and S. miltiorrhiza extracts ameliorated hypertension and atherosclerosis in L-NAME-treated rats in a dose-dependent manner. In addition, a mixture of C. cassia and S. miltiorrhiza had an additive effect to reduce blood pressure, increase blood flow, and normalize aortic tissue. This mixture demonstrated anti-oxidative and anti-inflammatory activities in vitro. In conclusion, although further analysis of the therapeutic mechanism is required, the anti-hypertensive and anti-atherosclerotic effects of this mixture are likely mediated by increased eNOS expression, and its anti-oxidative and anti-inflammatory activities.

• Journal of the Korean Chemical Society
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• v.30 no.4
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• pp.394-402
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• 1986

Detonation reaction in L.P.G./$O_2$ mixture gas has been investigated over the L.P.G. concentration range of 3∼45 volume%. The variation of detonation velocity with mixture ratio is very interesting as it shows and inflection point near at the stoichiometric ratio. This might be ascribed to the fact that the detonation reactions at fuel-rich condition and fuel-lean condition proceed via different mechanisms. The maximum detonation velocity of 2.65km/sec occurs not at stoichiometric ratio(${\phi}$=1) but at fuel-rich condition (${\phi}$=1.57). Assuming that a stable detonation wave must propagates with the constant velocity, The upper and lower limit of detonation were determined and found to be 40.0 and 3.40 L.P.G. volume% respectively. The shock-heating technique was also utilized for the measurement of self-ignition temperature onsetting a stable detonation wave at varous mixture ratios. The self-ignition temperature at stoichiometric ratio is $742{\pm}3{\circ}K$ and the self-ignition temperature increases as the mixture ratio deviates from the stoichiometric condition.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.18-25
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• 2015

To understand the metabolism of flavonoid rhamnoglycosides by human intestinal microbiota, we measured the metabolic activity of rutin and poncirin (distributed in many functional foods and herbal medicine) by 100 human stool specimens. The average α-L-rhamnosidase activities on the p-nitrophenyl-α-L-rhamnopyranoside, rutin, and poncirin subtrates were 0.10 ± 0.07, 0.25 ± 0.08, and 0.15 ± 0.09 pmol/min/mg, respectively. To investigate the enzymatic properties, α-L-rhamnosidase-producing bacteria were isolated from the specimens, and the α-L-rhamnosidase gene was cloned from a selected organism, Bifidobacterium dentium, and expressed in E. coli. The cloned α-L-rhamnosidase gene contained a 2,673 bp sequcence encoding 890 amino acid residues. The cloned gene was expressed using the pET 26b(+) vector in E. coli BL21, and the expressed enzyme was purified using Ni²⁺-NTA and Q-HP column chromatography. The specific activity of the purified α-L-rhamnosidase was 23.3 µmol/min/mg. Of the tested natural product constituents, the cloned α-L-rhamnosidase hydrolyzed rutin most potently, followed by poncirin, naringin, and ginsenoside Re. However, it was unable to hydrolyze quercitrin. This is the first report describing the cloning, expression, and characterization of α-L-rhamnosidase, a flavonoid rhamnoglycosidemetabolizing enzyme, from bifidobacteria. Based on these findings, the α-L-rhamnosidase of intestinal bacteria such as B. dentium seem to be more effective in hydrolyzing (1 →6) bonds than (1 →2) bonds of rhamnoglycosides, and may play an important role in the metabolism and pharmacological effect of rhamnoglycosides.

• BMB Reports
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• v.30 no.2
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• pp.113-118
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• 1997

Aspartase from Hafnia alvei was inactivated by N-ethylmaleimide (NEM) and 5,5' -Dithiobis-(2-znitrobenzoic acid) (DTNB) following pseudo-first order kinetics. Their apparent reaction orders were 0.83 and 0.50 for NEM and DTNB modifications, respectively, indicating that inactivation was due to a sulfhydryl group in the active site of aspartase and participation of the sulfhydryl group in an essential step in the catalytic reaction. When aspartase was modified by DTNB, the enzyme activity was restored by dithiothreitol treatment, indicating that cysteine residuetsl islarel possibly at or near the active site. The pH-dependence of the inactivation rate by NEM suggested that an amino acid residue having pK value of 8.3 was involved in the inactivation. When aspartase was incubated with NEM and L-aspartate together, L-aspartate markedly protected the enzyme from inactivation by NEM, but the other reagents used did not.