• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.647-657
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• 2016

In this study, the antioxidative effects and active component analysis of 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from Prunella vulgaris L. were investigated. The free radical scavenging activities ($FSC_{50}$) was investigated at 50% ethanol extract ($15.25{\mu}g/mL$), ethyl acetate fraction ($8.68{\mu}g/mL$), and aglycone fraction ($8.25{\mu}g/mL$) respectively. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay was investigated at 50% ethanol extract ($4.68{\mu}g/mL$), ethyl acetate fraction ($1.00{\mu}g/mL$), and aglycone fraction($1.02{\mu}g/mL$) respectively. In the cellular protective effect against $^1O_2$ induced cellular damage of human erythrocytes, extract/fractions of P. vulgaris L. were increased in a concentration dependent manner($1{\sim}25{\mu}g/mL$). Especially, ${\tau}_{50}$ of aglycone fraction at concentrations of $25{\mu}g/mL$ showed the most protective effects at 337.9 min. It's showed nine times higher (+)-${\alpha}$-tocopherol (${\tau}_{50}=38.7min$) as typical antioxidant in the $^1O_2$-induced photohemolysis of human erythrocytes. TLC and HPLC were used to analyse active components in the ethyl acetate fraction and aglycone fraction of P. vulgaris L. In ethyl acetate fraction, caffeic acid, rosmarinic acid, quercetin 3-${\beta}$-D-glucoside, rutin, kaempferol-3-O-rutinoside, astragalin (kaempferol-3-O-glucoside) were identified. In aglycone fraction, caffeic acid, rosmarinic acid, quercetin, kaempferol were identified. These results indicated that extract/fraction of P. vulgaris L. is may be used in cosmetics industry as natural antioxidants by quenching and/or scavenging $^1O_2$ and other ROS, and protecting cellular membranes.

• Journal of Life Science
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• v.31 no.3
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• pp.356-365
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• 2021

Recently, we sequenced the entire genome of a freshwater agar-degrading bacterium Cellvibrio sp. KY-GH-1 (KCTC13629BP) to explore genetic information encoding agarases that hydrolyze agarose into monomers 3,6-anhydro-L-galactose (L-AHG) and D-galactose. The KY-GH-1 strain appeared to possess nine β-agarase genes and two α-neoagarobiose hydrolase (α-NABH) genes in a 77-kb agarase gene cluster. Based on these genetic information, the KY-GH-1 strain-caused agarose degradation into L-AHG and D-galactose was predicted to be initiated by both endolytic GH16 and GH86 β-agarases to generate NAOS (NA4/NA6/NA8), and further processed by exolytic GH50 β-agarases to generate NA2, and then terminated by GH117 α-NABHs which degrade NA2 into L-AHG and D-galactose. More recently, by employing E. coli expression system with pET-30a vector we obtained three recombinant His-tagged GH50 family β-agarases (GH50A, GH50B, and GH50C) derived from Cellvibrio sp. KY-GH-1 to compare their enzymatic properties. GH50A β-agarase turned out to have the highest exolytic β-agarase activity among the three GH50 isozymes, catalyzing efficient NA2 production from the substrate (agarose, NAOS or AOS). Additionally, we determined that GH117A α-NABH, but not GH117B α-NABH, could potently degrade NA2 into L-AHG and D-galactose. Sequentially, we examined the enzymatic characteristics of GH50A β-agarase and GH117A α-NABH, and assessed their efficiency for NA2 production from agarose and for production of L-AHG and D-galactose from NA2, respectively. In this review, we describe the benefits of recombinant GH50A β-agarase and GH117A α-NABH originated from Cellvibrio sp. KY-GH-1, which may be useful for the enzymatic hydrolysis of agarose for mass production of L-AHG and D-galactose.

• The Korean Journal of Mycology
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• v.43 no.4
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• pp.260-266
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• 2015

To examine the changes in resistance to benomyl of Fusarium species causing bakanae disease, Fusarium isolates were collected in Korea, and pathogenicity tests were performed using rice seeds in vitro. Minimum inhibitory concentration (MIC) and effective concentration of 50% ($EC_{50}$) values of isolates were examined using the agar dilution method. High frequency distribution of MIC values to benomyl against isolates collected in 2006~2007 and 2013~2014 years were $1.5625{\sim}3.125{\mu}g/mL$ and more than $25{\mu}g/mL$, respectively. The mean $EC_{50}$ value of isolates to benomyl increased from $1.6397{\mu}g/mL$ in 2006~2007 to $2.4892{\mu}g/mL$ in 2013~2014. Based on MIC and $EC_{50}$ values of isolates, the moderate resistance of benomyl were determined as more than $25{\mu}g/mL$ of MIC and less $2.4{\mu}g/mL$ of $EC_{50}$ value, and resistant isolates to benomyl were determined as more than $2.4{\mu}g/mL$ of $EC_{50}$ value. Compared with the ratio of resistant isolates in 2006~2007, the ratio of resistance isolates in 2013~2014 increased from 12.5% to 36.4%. In addition, multiple resistant isolates to prochloraz as well as benomyl increased to 20.3% in 2013~2014.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.1
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• pp.25-35
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• 2008

In this study, the antioxidative effects and inhibitory effects on elastase and tyrosinase of Geranium nepalense extracts were investigated. The free radical(1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) of extract/fractions of Geranium nepalense were in the order: 50% ethanol extract(15.0 ${\mu}g/mL$)${\mu}g/mL$). ${\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities($OSC_{50}$) of some Geranium nepalense extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescense assay. The order of ROS scavenging activities were 50% ethanol extract($OSC_{50},\;0.23{\mu}g/mL$)${\mu}g/mL$)${\mu}g/mL$). Deglycosylated flavonoid fraction showed the most prominent scavenging activity. The protective effects of extract/fractions of Geranium nepalense on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Geranium nepalense extracts suppressed photohemolysis in a concentration dependent manner, particularly deglycosylated flavonoid fraction exhibited the most prominent celluar protective effect (${\tau}_{50}$, 676.7 min at 50 ${\mu}g/mL$). The inhibitory effect of aglycone fraction on tyrosinase($IC_{50}$, 70.0 ${\mu}g/mL$) and elastase ($IC_{50}$, 19.9 ${\mu}g/mL$) was very high. Aglycone fractions obtained from the deglycosylation reaction of ethyl-acetate fraction among the Geranium nepalense extracts, showed 2 bands in TLC and 2 peaks in HPLC experiments (370 nm). Two components were identified as quercetin(composition ratio, 15.3%), kaempferol(82.8%). These results indicate that extract/fractions of Geranium nepalense can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. And component analysis of Geranium nepalense extract and inhibitory activity on elastase of the aglycone fraction could be applicable to new functional cosmetics for smoothing wrinkles.

• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.33-40
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• 2006

Residual pesticides discharged from diffuse sources at agricultural area in association with suspended solid will be settled at downstream, and may degrade surface water quality. This research studied dechlorination kinetic of atrazine, one of triazine-category herbicide, using zero-valent iron (ZVI) in sediment. It can be observed from the experiments that buffer capacity of sediment helped pH maintained beutral, resulted in continuous dechlorination. Sediments were spiked with atrazine at 10, 30, and 50 mg atrazine/L of total sediment for batch experiments. Dechlorination constants were $1.38x10^{-1}/d$ for the initial concentration of 10 mg/L, $1.29x10^{-l}/d$ for 30 mg/L, and $7.43x10^{-2}/d$ for 50 mg/L while dechlorination constants of initial concentration of 50 mg/L without ZVI adding were estimated as $3.05x10^{-2}/d. Half lifes atrazine by ZVI were estimated as 5.03 d fur 10 mg/L, 5.38 d for 30 mg/L, and 9.33 d for 50 mg/L, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.281-286
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• 2015

In this study, free radical scavenging activities (ABTS, DPPH, NBT, TBARS, and ORAC) and anti-obesity potential were evaluated using 50% ethanol extract from fermented Curcuma longa L. (FCE50). FCE50 showed free radical scavenging activities and anti-oxidant potential. Lipid accumulation and intracellular TG content were significantly reduced by 25.8% and 28.6%, respectively, by $250{\mu}g/mL$ of FCE50 compared to adipocytes. Glucose uptake was significantly reduced by 12.0%. FCE50 significantly reduced mRNA expression of acetyl-CoA carboxylase in 3T3-L1 cells. These results indicate that the anti-adipogenic effect of FCE50 might be due to its radical scavenging activity and anti-oxidant potential.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.332-336
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• 2005

The average specific growth rate of C. reinhardtii (${\mu}$) was decreased with increase in biocide concentrations. The toxicity of biocides toward was as follows (in descending order of toxicities): herbicide 〉 pesticide 〉fungicide. $EC_{50}$ in each biocide was 0.0017 mg/L, 1.06 mg/L and 13.3 mg/L for herbicide, pesticide and fungicide respectively. When herbicide and pesticide were mixed, $EC_{50}$ was decreased by $2.7{\times}10^{-7}mg/L$. $EC_{50}$ in effective components of each biocide was 5.26 mg/L, 9.37 mg/L and 20.58 mg/L for herbicide, pesticide and fungicide respectively. Mixed main components of herbicide and pesticide caused to decrease by 3.10 mg/L.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.3
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• pp.275-282
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• 2012

In this study, the antioxidative effects of extracts from different parts of Juncus effusus L. were investigated. The three parts (above-ground part, below-ground part, medulla part) were selected. 50 % ethanol extract, ethyl acetate and aglycone fractions of J. effusus L. were used in experiments. The highest DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activities ($FSC_{50}$) was shown by medulla part (42.9 ${\mu}g/mL$) in 50 % ethanol extracts, below-ground part (12.1 ${\mu}g/mL$) in ethyl acetate fractions, and below-ground part (12.1 ${\mu}g/mL$) in aglycone fractions. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system using the luminol-dependent chemiluminescence assay showed the most prominent effect of medulla part (0.29 ${\mu}g/mL$) in 50 % ethanol extracts, below-ground part (0.25 ${\mu}g/mL$) in ethyl acetate fractions, and medulla part (0.20 ${\mu}g/mL$) in aglycone fractions. The cellular protective effects of extract/fractions of J. effusus L. on the rose-bengal sensitized photohemolysis of human erythrocytes were increased in a concentration dependent manner (0.5 ~ 10 ${\mu}g/mL$). Especially, aglycone fraction of medulla part at a concentration of 10 ${\mu}g/mL$ showed the most prominent protective effect among all extracts (${\tau}_{50}$, 321.0 min). These results indicate that extracts from below-ground part and medulla part of J. effusus L. extracts can be used as an natural antioxidant. Particularly, J. effusus L. can protect suggesting a high ${\tau}_{50}$ skin where many $^1O_2$ was generated by sunlight exposure.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.247-250
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• 2014

A lipid-soluble extract in ginseng marc was prepared by n-hexane extraction to evaluate its antioxidant and anticancer potential. A hexane extract of ginseng marc (HEGM) possessed a 2,2-diphenyl-1-picryl-hydrazyl free radical scavenging activity which was related to the amount of total phenolics. Also, HEGM showed a potent inhibitory activity on human non-small cell lung cancer (A549, $GI_{50}=34.0{\mu}g/mL$) and colon cancer (SNU-C4, $GI_{50}=45.2{\mu}g/mL$) cells proliferation in vitro in a concentration-dependent manner as did the hexane extract of ginseng with $GI_{50}$ values of $20.0{\mu}g/mL$ in A549 and $37.0{\mu}g/mL$ in SNU-C4. These results imply that HEGM can be utilized as an antioxidant and anticancer substance.

• 한국해양학회지
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• v.13 no.1
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• pp.35-43
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• 1978

Short-term acute toxicity of mercury, cadmium and copper to arkshell, Anadara broughtonii, and to oyster, Crassostrea gigas, was determinedby static bioassays from 20 May to 27 June in 1977. During the observations of the opening rate of the shell mercury was the most sensitive toxicant of the three toxic substances to the test animals and caused them to close their shellvalves together after being exposed to a mercury solution for an hour during the test. Opening rate to cadmium and copper increased gradually at the higher concentration. the 96hr-LC50 values for the test animals are 4.84mg/l for mercury and 1.86mg/l for cadmium, while the 72hr-LC50 value for copper is 0.31mg/l. the death rate of oysters for cadmium showed lower than that of the mercury and copper test solutions. The 96hr-LC50 values of mercury, copper and cadmium were 1.1mg/l, 2.54mg/l and 19.5mg/l, respectively. For oysters mercury was the most toxic substance, and cadmium was the least toxic one. the medium lethal time (LT 50) value decreased gradually at higher concentration of heavy metals. The LT 50 of 2mg/l was found within 96 hours ofr copper, 104 hours for mercury and 121 hours for cadmium. The lethal threshold concentrations for 7 days were found to be about 1mg/l for mercury and copper, and 2mg/l for cadmium.