• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.13-19
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• 1999

In order to investigate the composition and the actual status of extractive nitrogenous compounds in the fresh 'Gae-bul' (echiuroid), a kind of echiurida (Urechis unicinctus), the extract was analyzed separately into extractive nitrogen, free amino acids (FAAs), oligopeptides, nucleotides and related compounds, quaternary ammonium bases, and guanidino compounds, using specimens collected at fish market in April 1988. The extractive nitrogen of echiuroid was $601{\sim}610mg/100g$. Thirty-two kinds of FAAs were found, and the total of them in it was $2,437{\sim}2,609\;mg$. Glycine, alanine, taurine, and serine were the major FAAs in the echiuroid extracts. The large amount of glycine $(1,075{\sim}1,171mg)$ was noted in the extract. The sum of ATP and its related compounds was $3.04{\sim}3.12\;{\mu}mol/g$, and predominant compound was the AMP. Besides, CTP, GTP, UTP and their related compounds were also detected, and the total amount of them was $1.92{\sim}3.74\;{\mu}mol/g$. The lower homarine, trigonelline, TMAO, TMA, and creatine were detected in the extracts. The extractive nitrogenous constituents of medium size and large size echiuroid were almost the same level each other. The total nitrogens of the compounds analyzed for each samples accounted for more than 90% of the extractive nitrogen in this study.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.219-228
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• 2015

Excessive microglial activation and subsequent neuroinflammation lead to synaptic loss and dysfunction as well as neuronal cell death, which are involved in the pathogenesis and progression of several neurodegenerative diseases. Thus, the regulation of microglial activation has been evaluated as effective therapeutic strategies. Although dieckol (DEK), one of the phlorotannins isolated from marine brown alga Ecklonia cava, has been previously reported to inhibit microglial activation, the molecular mechanism is still unclear. Therefore, we investigated here molecular mechanism of DEK via extracellular signal-regulated kinase (ERK), Akt and nicotinamide adenine dinuclelotide phosphate (NADPH) oxidase-mediated pathways. In addition, the neuroprotective mechanism of DEK was investigated in microglia-mediated neurotoxicity models such as neuron-microglia co-culture and microglial conditioned media system. Our results demonstrated that treatment of anti-oxidant DEK potently suppressed phosphorylation of ERK in lipopolysaccharide (LPS, $1{\mu}g/ml$)-stimulated BV-2 microglia. In addition, DEK markedly attenuated Akt phosphorylation and increased expression of $gp91^{phox}$, which is the catalytic component of NADPH oxidase complex responsible for microglial reactive oxygen species (ROS) generation. Finally, DEK significantly attenuated neuronal cell death that is induced by treatment of microglial conditioned media containing neurotoxic secretary molecules. These neuroprotective effects of DEK were also confirmed in a neuron-microglia co-culture system using enhanced green fluorescent protein (EGFP)-transfected B35 neuroblastoma cell line. Taken together, these results suggest that DEK suppresses excessive microglial activation and microglia-mediated neuronal cell death via downregulation of ERK, Akt and NADPH oxidase-mediated pathways.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.1-8
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• 1991

Developmental micropropagation method and somatic embryogenesis for hybrid poplars, Populns ehrarnericana Eco28, P. nigra ${\times}$ P. moximowiczii 62-9, were established using nodule culture system. Calli of Eco28 and 62-9 clone were initiated from leaf explant on the medium with 0.5mg/l and 2.0mg/l 2, 4-D, respectively. Cell suspension culture was established from callus derived from leaf explant culture. When suspended on MS medium with optimal combination of BA and NAA fine nodules were obtained after 2 weeks of culture. For shoot regeneration, nodules were transferred into liquid and agar solidified medium. Numerous shoots were regenerated from nodules of 62-9 on liquid media. Organogenesis was effectively achieved on agar solidified regeneration media containing different concentrations of BA and adenine sulfate. Average numbers of 27 and 24 shoots per nodule were induced from 62-1 and Eco28 clones after 8 weeks of culture, respectively. In addition, somatic embryogenesis also occurred in the same regeneration medium. This procedure can be applied to vegetative propagation, utilization of somaclonal variation, production of secondary metabolite and materials of biotechnology research.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1519-1526
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• 2010

The behavior of peptide or protein solutes in saline aqueous solution is a fundamental topic in physical chemistry. Addition of ions can strongly alter the thermodynamic and physical properties of peptide molecules in solution. In order to study the effects of added ionic salts on protein conformation and dynamics, we have used the molecular dynamics (MD) simulations to investigate the behavior of Staphylococcus aureus Hfq protein under two different ionic concentrations: 0.1 M NaCl and 1.0 M NaCl in presence and absence of RNA (a hepta-oligoribonucleotide AU5G). Hfq, a global regulator of gene expression is highly conserved and abundant RNA-binding protein. It is already reported that in vivo the increase of ionic strength results in a drastic reduction of Hfq affinity for $Q{\beta}$ RNA and reduces the tendency of aggregation of Escherichia coli host factor hexamers. Our results revealed the crucial role of 0.1 M NaCl Hfq system on the bases with strong hydrogen bonding interactions and by stabilizing the aromatic stacking of Tyr42 residue of the adjacent subunits/monomers with the adenine and uridine nucleobases. An increase in RNA pore diameter and weakened compactness of the Hfq-RNA complex was clearly observed in 1.0 M NaCl Hfq system with bound RNA. Aggregation of monomers in Hfq and the interaction of Hfq with RNA are greatly affected due to the presence of high ionic strength. Higher the ionic concentration, weaker is the aggregation and interaction. Our results were compatible with the experimental data and this is the first theoretical report for the experimental study done in 1980 by Uhlenbeck group for the present system.

• The Korean Journal of Zoology
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• v.31 no.3
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• pp.191-206
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• 1988

Chick embryos which have received a single injection of the organophosphate compound,malathion (0.1 mg, 0.5 mg, 1.0 mg or 2.0 mg in 0.05 ml of corn oil) via the yolk sac at certain times (2 daya, 4 days or 6 days after incubation) have been investigated. After 9 days of incubation, chick embryos were harvested to investigate the effects of malathion on the development of cerebrum morphologically and biochemically. The effects of simultaneous injection of malathion and nicotinamide were also compared. On ultrastructural examination, neurons in cerebral cortex showed to be inhibited in their differentiation by malathion; nuclear irregularity, swelling of endoplasmic reticulum, and cytoplasmic vacuoles were observed. On cytochemical study of acetylcholinesterase(AChE) by electron microscope, the positive reaction products of this enryme were localized at the membrane of nucleus and endoplasmic reticulum of neurons. Inhibition of AChE activty was severe in groups treated with relatively low doses, which was consistent with the results of spectrophotometric analysis. The activity of lactate dehydrogenase(LDH) of cerebrum in groups treated with malathion was higher than that of the control group. The nicotinamide adenine dinucleotide(NAD) content of chick embruo treated with malathioti decreased significantly, and nicotinamide coinjection raised the NAD level as compared with the control group, thus preventing malathion-induced momhological alteration. In conclusion, it is suggested that malathion changes the ultrastructure of differentiating neurons and alters some enzyme activities in chick embryo cerebrum, and the severity of which is consistently dose-or age-dependent.

• Journal of Ginseng Research
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• v.41 no.1
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• pp.23-30
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• 2017

Background: Ginsenoside Rg1 is a class of steroid glycoside and triterpene saponin in Panax ginseng. Many studies suggest that Rg1 suppresses adipocyte differentiation in 3T3-L1. However, the detail molecular mechanism of Rg1 on adipogenesis in 3T3-L1 is still not fully understood. Methods: 3T3-L1 preadipocyte was used to evaluate the effect of Rg1 on adipocyte development in the differentiation in a stage-dependent manner in vitro. Oil Red O staining and Nile red staining were conducted to measure intracellular lipid accumulation and superoxide production, respectively. We analyzed the protein expression using Western blot in vitro. The zebrafish model was used to investigate whether Rg1 suppresses the early stage of fat accumulation in vivo. Results: Rg1 decreased lipid accumulation in early-stage differentiation of 3T3-L1 compared with intermediate and later stages of adipocyte differentiation. Rg1 dramatically increased CAAT/enhancer binding protein (C/EBP) homologous protein-10 (CHOP10) and subsequently reduced the $C/EBP{\beta}$ transcriptional activity that prohibited the initiation of adipogenic marker expression as well as triglyceride synthase. Rg1 decreased the expression of extracellular signal-regulated kinase 1/2 and glycogen synthase kinase $3{\beta}$, which are also essential for stimulating the expression of $CEBP{\beta}$. Rg1 also reduced reactive oxygen species production because of the downregulated protein level of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase 4 (NOX4). While Rg1 increased the endogenous antioxidant enzymes, it also dramatically decreased the accumulation of lipid and triglyceride in high fat diet-induced obese zebrafish. Conclusion: We demonstrated that Rg1 suppresses early-stage differentiation via the activation of CHOP10 and attenuates fat accumulation in vivo. These results indicate that Rg1 might have the potential to reduce body fat accumulation in the early stage of obesity.

• Journal of Life Science
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• v.20 no.5
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• pp.768-774
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• 2010

In this study, we investigated the antioxidant activities, alcohol metabolizing activities, nitrite scavenging ability, angiotensin converting enzyme (ACE), and elastase inhibitory effects of hot water extract from Makgeoly (HWM). Antioxidant activities were measured by using 2,2.diphenyl.1.picryl.hydrazyl (DPPH) free radical scavenging activity and SOD (superoxide dismutase).like activity. The DPPH radical scavenging activity and SOD.like activity of HWM were remarkably increased in a dose.dependent manner and were 48.0% and 98.7% at 10 mg/ml, respectively. To determine the influence of HWM on alcohol metabolizing activity, the generating activities of reduced.nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were measured. The facilitating rates of ADH and ALDH activity by HWM were remarkably increased in a dose.dependent manner and were 70.2% and 64.1% at 10 mg/ml, respectively. The inhibitory activity against angiotensin converting enzyme (ACE) of HWM was increased in a dose.dependent manner and was 74.2% at 10 mg/ml. The nitrite scavenging ability of HWM showed the most remarkable effect at pH 1.2 and 2 mg/ml. These results indicated that HWM may have valuable biological properties owing to their antioxidant activities, ADH and ALDH activity, nitrite scavenging ability, and ACE inhibitory activity.

• Journal of Pharmacopuncture
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• v.18 no.2
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• pp.7-18
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• 2015

Objectives: Lawsone (1,4 naphthoquinone) is a non redox cycling compound that can be catalyzed by DT diaphorase (DTD) into 1,2,4-trihydroxynaphthalene (THN), which can generate reactive oxygen species by auto oxidation. The purpose of this study was to evaluate the toxicity of the phytomarker 1,4 naphthoquinone and its metabolite THN by using the molecular docking program AutoDock 4. Methods: The 3D structure of ligands such as hydrogen peroxide ($H_2O_2$), nitric oxide synthase (NOS), catalase (CAT), glutathione (GSH), glutathione reductase (GR), glucose 6-phosphate dehydrogenase (G6PDH) and nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) were drawn using hyperchem drawing tools and minimizing the energy of all pdb files with the help of hyperchem by $MM^+$ followed by a semi-empirical (PM3) method. The docking process was studied with ligand molecules to identify suitable dockings at protein binding sites through annealing and genetic simulation algorithms. The program auto dock tools (ADT) was released as an extension suite to the python molecular viewer used to prepare proteins and ligands. Grids centered on active sites were obtained with spacings of $54{\times}55{\times}56$, and a grid spacing of 0.503 was calculated. Comparisons of Global and Local Search Methods in Drug Docking were adopted to determine parameters; a maximum number of 250,000 energy evaluations, a maximum number of generations of 27,000, and mutation and crossover rates of 0.02 and 0.8 were used. The number of docking runs was set to 10. Results: Lawsone and THN can be considered to efficiently bind with NOS, CAT, GSH, GR, G6PDH and NADPH, which has been confirmed through hydrogen bond affinity with the respective amino acids. Conclusion: Naphthoquinone derivatives of lawsone, which can be metabolized into THN by a catalyst DTD, were examined. Lawsone and THN were found to be identically potent molecules for their affinities for selected proteins.

• Toxicological Research
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• v.33 no.4
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• pp.265-272
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• 2017

Aryl hydrocarbons such as 3-nitrobenzanthrone (NBA), 4-aminobiphenyl (ABP), acetylaminofluorene (AAF), benzo(a)pyrene (BaP), and 1-nitropyrene (NP) form bulky DNA adducts when absorbed by mammalian cells. These chemicals are metabolically activated to reactive forms in mammalian cells and preferentially get attached covalently to the $N^2$ or C8 positions of guanine or the $N^6$ position of adenine. The proportion of $N^2$ and C8 guanine adducts in DNA differs among chemicals. Although these adducts block DNA replication, cells have a mechanism allowing to continue replication by bypassing these adducts: translesion DNA synthesis (TLS). TLS is performed by translesion DNA polymerases-Pol ${\eta}$, ${\kappa}$, ${\iota}$, and ${\zeta}$ and Rev1-in an error-free or error-prone manner. Regarding the NBA adducts, namely, 2-(2'-deoxyguanosin-$N^2$-yl)-3-aminobenzanthrone (dG-$N^2$-ABA) and N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone (dG-C8-ABA), dG-$N^2$-ABA is produced more often than dG-C8-ABA, whereas dG-C8-ABA blocks DNA replication more strongly than dG-$N^2$-ABA. dG-$N^2$-ABA allows for a less error-prone bypass than dG-C8-ABA does. Pol ${\eta}$ and ${\kappa}$ are stronger contributors to TLS over dG-C8-ABA, and Pol ${\kappa}$ bypasses dG-C8-ABA in an error-prone manner. TLS efficiency and error-proneness are affected by the sequences surrounding the adduct, as demonstrated in our previous study on an ABP adduct, N-(2'-deoxyguanosine-8-yl)-4-aminobiphenyl (dG-C8-ABP). Elucidation of the general mechanisms determining efficiency, error-proneness, and the polymerases involved in TLS over various adducts is the next step in the research on TLS. These TLS studies will clarify the mechanisms underlying aryl hydrocarbon mutagenesis and carcinogenesis in more detail.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.53-65
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• 2020

Here, we describe an efficient and rapid protocol for the micropropagation of Thymus pallidus Cosson ex Batt., a very rare medicinal and aromatic plant in Morocco. After seed germination, we tested the effect of different macronutrients, cytokinins alone or in combination with gibberellic acid (GA₃) or auxins, on T. pallidus plantlet growth. We found that Margara macronutrients (N₃₀K) had the best effect on the in vitro development of the plantlets. The addition of 0.93 μM/L 1,3-diphenylurea (DPU), 0.46 μM/L adenine (Ad), and 0.46 and 0.93 μM/L kinetin (Kin) resulted in the best shoot multiplication and elongation. In addition, the combination of 0.46 μM/L Kin, DPU, or Ad with gibberellic acid, in particular, 0.46 μM/L Ad + 0.58 μM/L GA₃ and 0.46 μM/L Kin + 1.15 μM/L GA₃, led to better bud and shoot multiplication. Moreover, the integration of the combinations of 0.46 μM/L Kin and auxins, namely 0.46 μM/L Kin + 2.85 μM/L indole-3-acetic acid (IAA), 0.46 μM/L Kin + 2.85 or 5.71 μM/L indole-3-butyric acid (IBA), and 0.46 μM/L Kin + 0.3 or 0.57 μM/L 1-naphthaleneacetic acid (NAA), in the culture medium led to better root development and optimized aerial growth. Finally, the in vitro plants from the medium containing N₃₀K + 0.46 μM/L Kin + 2.85 μM/L IAA were successfully acclimatized; these plants served as a source for repeating in vitro culture.