• Journal of Ginseng Research
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• 제48권3호
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• pp.341-345
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• 2024

The objective of the study is to estimate the potential of gintonin, as an immune enhancing agent through natural killer cell (NK cell) activity in cyclophosphamide (CY)-induced immunosuppressive animals. Accumulated results reveals that, gintonin attenuated CY-induced immunosuppression and it might modulate NK cell activity to boost the immunity.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제53권2호
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• pp.187-195
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• 2008

Polyphenol oxidase (PPO) is implicated in discoloration of white salted noodles and other wheat based foods. PPO activity was evaluated to determine the effect on discoloration of noodle dough sheets prepared from 25 Korean wheat flours during storage and to screen experimental lines with low PPO activity in 52 Korean wheats. PPO activity was assayed with whole-seed and performed with L-dihydroxyphenylalanine (L-DOPA) as substrates. Absorbance by L-DOPA assay of 25 Korean wheats was from 0.285 to 1.368 at 475 nm. PPO activity was significantly related with grain characteristics, including 1000-kernel weight and grain colors. In flour characteristics, PPO activity positively correlated with ash and protein content (r = 0.658, P < 0.001 and r = 0.424, P < 0.05, respectively) and negatively correlated with $L^*$ value of flour (r = 0.412, P < 0.05). In the changes of color of noodle dough sheet, $L^*$ and $b^*$ values consistently decreased and $a^*$ value increased during storage. PPO activity negatively correlated with $L^*$ value of noodle dough sheet during storage (r = 0.566, P < 0.01 at 2 hr, r = 0.547, P < 0.01 at 24 hr, and r = 0.509, P < 0.01 at 48 hr). But, no significant relationship was found in between PPO activity, $a^*$ and $b^*$ values during storage. The 52 Korean wheat lines examined in this study were divided into 3 different groups, low (< 0.500), medium (0.501-0.999) and high level (> 1.000), on the basis of the level of PPO activity. Twenty two Korean wheat lines showed low level of PPO activity and Suwon 252, 277 and 280 showed lower PPO activity (< 0.200) than others.

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.378-386
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• 2009

A sequential optimization strategy, based on statistical experimental designs, is employed to enhance the production of alkaline protease by a Bacillus pseudofirmus local isolate. To screen the bioprocess parameters significantly influencing the alkaline protease activity, a 2-level Plackett-Burman design was applied. Among 15 variables tested, the pH, peptone, and incubation time were selected based on their high positive significant effect on the protease activity. A near-optimum medium formulation was then obtained that increased the protease yield by more than 5-fold. Thereafter, the response surface methodology(RSM) was adopted to acquire the best process conditions among the selected variables, where a 3-level Box-Behnken design was utilized to create a polynomial quadratic model correlating the relationship between the three variables and the protease activity. The optimal combination of the major medium constituents for alkaline protease production, evaluated using the nonlinear optimization algorithm of EXCEL-Solver, was as follows: pH of 9.5, 2% peptone, and incubation time of 60 h. The predicted optimum alkaline protease activity was 3,213 U/ml/min, which was 6.4 times the activity with the basal medium.

• The Plant Pathology Journal
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• 제19권4호
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• pp.189-194
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• 2003

The effects of prochloraz on membrane permeability and germination of uredospores of Puccinia recondita were investigated to determine its potential mode of action on wheat leaf rust control activity. Disease control activity of ergosterol biosynthesis inhibitors (EBIs) and their activities on uredospore membrane permeability and germination were examined with wheat leaf rust pathogen, both in vitro and in vivo. While wheat leaf rust was not controlled by prochloraz, electrolytic leakage and spore germination of P. recondita uredospore was the highest with the use of prochloraz among the eight fungicides tested. Prochloraz stimulated uredospore of P. recondita to germinate at a higher ratio. Although certain EBIs, such as hexaconazole, showed excellent control activity, their effects on uredospore membrane permeability and germination was much inferior to prochloraz. Therefore, results of this study suggest that effects of EBIs on membrane permeability and germination of uredospore are not always correlated with their disease control activity.

• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.3005-3008
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• 2014

Human ChlR1 protein (hChlR1), a member of the cohesion establishment factor family, plays an important role in the segregation of sister chromatids for maintenance of genome integrity. We previously reported that hChlR1 interacts with hFen1 and stimulates its nuclease activity on the flap-structured DNA substrate covered with RPA. To elucidate the relationship between hChlR1 and Okazaki fragment processing, the effect of hChlR1 on in vitro nuclease activities of hFen1 and hDna2 was examined. Independent of ATPase activity, hChlR1 stimulated endonuclease activity of hFen1 but not that of hDna2. Our findings suggest that the acceleration of Okazaki fragment processing near cohesions may aid in reducing the size of the replication machinery, thereby facilitating its entry through the cohesin ring.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1210-1215
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• 2006

The properties related to the temperature and oxygen stability of the cytoplasmic hydrogenases from the fermentative strict anaerobic bacterium, Clostridium butyricum NCIB 9576 (Cl. butyricum), and purple sulfur phototrophic bacterium, Thiocapsa roseopersicina NCIB 8347 (T. roseopersicina), were compared. The optimum temperatures for the growth of Cl. butyricum and T. roseopersicina were 37$^{\circ}C$ and 25$^{\circ}C$, respectively, whereas those for the H$_2$ evolution of the cytoplasmic hydrogenases prepared from Cl. butyricum (C-H$_2$ase) and T. roseopersicina (T-H$_2$ase) were 45$^{\circ}C$ and 65$^{\circ}C$, respectively. The T-H$_2$ase was more thermostable than the C-H$_2$ase and retained its full activity for 5 h at 50$^{\circ}C$ under anaerobic conditions and 90% of its activity at 60$^{\circ}C$, whereas the C-H$_2$ase lost its activity drastically at 50$^{\circ}C$. The optimum pHs for H$_2$ oxidation of the C-H$_2$ase and T-H$_2$ase were 9.0 and 7.5, respectively. Both enzymes showed a maximum H$_2$ evolution activity at pH 7.0. Under aerobic conditions, 80% of the T-H$_2$ase activity was retained for 10 h at 30$^{\circ}C$, and 50% of the activity remained after 6 days under the same experimental conditions. However, the C-H$_2$ase was labile to oxygen and lost its activity immediately on exposure to air. Therefore, these properties of the T-H$_2$ase are expected to be advantageous for application in in vitro biological H$_2$ production systems.

• Applied Biological Chemistry
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• 제41권4호
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• pp.246-250
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• 1998

The cytotoxic activity of methanol extracts of 25 leguminous seeds in vitro was evaluated by sulforhodamine B assay, using the five human solid A549 lung, SK-OV-2 ovarian, SK-MEL-2 melanoma, XF-498 CNS and HCT-15 colon tumor cell lines. The responses varied with both cell line arid leguminous seed used. Extracts of Canavalia lineata and Glycine soja revealed potent cytotoxic activity against A549 arid SK-MEL-2 cell lines. Moderate activity was observed in the extracts of Cassia obtusifolia and Glyeine max var. chungtae, and C. lineata and Vigna angulasis against SK-MEL-2 and HCT-15 cell lines, respectively. The other seed extracts were ineffective against model tumor cell lines. Because of their potent cytotoxic activities, the activity of each solvent fraction from C. lineata and G. soja was determined and the potent activity was produced from their chloroform fractions. As a naturally occurring therapeutic agent, leguminous seeds described could be useful for developing new types of anti-tumor agents.

• KSBB Journal
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• 제29권6호
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• pp.437-442
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• 2014

In vitro biological activities of Aloe vera gel and skin extracts were evaluated. Total polyphenol contents of Aloe vera skin were measured 41.12 mg/g. DPPH radical scavenging activity of Aloe vera skin-70% EtOH extract, Aloe vera skin-water extract, Aloe vera gel-70% EtOH extract and Aloe vera gel-water extract were 55%, 38%, 11% and 10%, respectively. In addition, 70% EtOH extract and water extract were compared with respect to SOD-like antioxidant activity of Aloe vera-70% EtOH extract has higher activity than Aloe vera water extract. Tyrosinase inhibition rate of Aloe vera gel extract was higher than Aloe vera skin extract. Alcohol dehydrogenase (ADH) and Acetaldehyde dehydrogenase (ALDH) relative percentage activity of Aloe vera gel extract were 126% and 216%, respectively. It was suggested that Aloe vera gel and skin extracts could be used as a functional biomaterial for functional food and cosmetics.

• The Plant Pathology Journal
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• 제22권3호
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• pp.289-294
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• 2006

Two isolates of mucous bacteria, mc75 and pc78, were isolated from fungal culture plate as culture contaminants with an interesting swarming motility. Both isolates were identified as Pseudomonas fluorescens based on microscopy, biochemical analysis, Biolog test and DNA sequence analysis of the 16S rRNA gene. Both strains have the exactly the same 16S rRNA gene sequences, and yet their biological control activity were not identical each other. In vitro analysis of antagonistic activity of two isolates against several plant pathogenic fungi indicated that both produced diffusible and volatile antifungal compounds of unknown identities. Treatment of the bacterial culture of P. fluorescens pc78 and its culture filtrate exhibited a strong biological control activity against rice sheath blight in vivo among six plant diseases tested. More effective disease control activity was obtained from treatment of bacterial culture than that of culture filtrate. Therefore, in addition to antifungal compound and siderophore production, other traits such as biofilm formation and swarming motility on plant surface may contribute to the biological control activity of P.fluorescens pc78 and mc75.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제44권1호
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• pp.64-70
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• 2011

Nitrate reductase (NR) is activated by nitrogen sources (${NO_3}^-$ and ${NH_4}^+$) and irradiance. This study investigated the effects of these factors on the NR activity of Ulva pertusa (Chlorophyta) and Ecklonia cava (Phaeophyta). In addition, the ammonium (${NH_4}^+$) and nitrate (${NO_3}^-$) uptake rates of the two species were examined. U. pertusa took up most of the ${NO_3}^-$ and ${NH_4}^+$ in the medium during a 3hour incubation, while E. cava had a relatively high uptake rate after 3 hours. The NR activities of the two species were affected by the nitrogen source and irradiance and were highest when they were exposed to ${NO_3}^-$-rich medium and high irradiance. However, the patterns of NR activity differed between the two species. In ${NO_3}^-$-rich medium and high irradiance, U. pertusa achieved the highest NR activity ($2.01{\pm}0.07\;{\mu}mol$ ${NO_2}^-$ $g^{-1}$ DW $h^{-1}$) within the first 3 hours and then this activity decreased drastically. By contrast, the NR activity of E. cava ($0.36{\pm}0.04\;{\mu}mol$ ${NO_2}^-$ $g^{-1}$ DW $h^{-1}$) was constant for 12 hours. When exposed to darkness, the NR activity of U. pertusa decreased dramatically, while that of E. cava increased gradually for 12 hours. Therefore, E. cava is able to maintain NR activity during the dark because of its adequate carbohydrate reserves and substrate.