• Journal of the Korean Applied Science and Technology
• /
• v.34 no.2
• /
• pp.236-243
• /
• 2017

In the present study, 70% ethanol extract, the ethyl acetate fraction were prepared from citron (Citrus junos)seed and their antioxidative ability was evaluated. The yields of extract and fractions were 5.1 and 0.9% per dried powder, respectively. In the 1,1-Phenyl-2-picrylhydrazyl (DPPH) radical test, free radical scavenging activities ($FSC_{50}$) of 70 % ethanol extract, ethyl acetate fraction were 512.1 and $514.0{\mu}g/mL$, respectively. Evaluation of total antioxidant capacities ($OSC_{50}$) using $Fe^{3+}$-EDTA system. Their $OSC_{50}$ of ethyl acetate fraction were $86.5{\mu}g/mL$. this antioxidant capacities higher than that of 70% ethanol extract. but lower than that of L-ascorbic acid ($1.72{\mu}g/mL$), known as a prominent water soluble antioxidant. The cellular protective effects on the $^1O_2$-induced cellular damage of rabbit erythrocytes were evaluated and the results showed that the extract was lower than (+)-${\alpha}$-tocopherol and low concentration of ethyl acetate fraction was similar to (+)-${\alpha}$-tocopherol. but not at high concentrations of ethtyl acetate fraction. it was able to induce cellular damage at high concentration.

• Food Science and Preservation
• /
• v.16 no.2
• /
• pp.179-185
• /
• 2009

To develop an Enoki mushroom packaging method, mushrooms were stored at $1^{\circ}C$ for 12 days after passive MAP packaging(PM), vacuum packaging(VM), and gas flushing packaging(AM), after investigation of film thickness influences on respiration rates and gas compositions(LDPE films 20, 40, and 60 m in thickness were tested). Enoki mushrooms had respiration rates of 26.4 mL $CO_2/kg/hour$ at $0^{\circ}C$, 80.0 mL $CO_2/kg/hour$ at $10^{\circ}C$, 130.9 mL $CO_2/kg/hour$ at $20^{\circ}C$, and 130.9 mL $CO_2/kg/hour$ at $30^{\circ}C$. A film thickness of 20 m was chosen for further tests to maintain the oxygen concentration above the minimum growth level; the thinnest film offered a higher gas transmittance rate than did the thicker films. No anaerobic respiration was evident over 12 days of storage using any packaging method, with the exception of VM. AM, using a high concentration of $CO_2$, restricted respiration rate. Mushrooms packaged using the VM method showed the greatest weight loss and extent of discoloration among the packaging methods tested, followed by AM mushrooms using 50% $CO_2/10%\;O_2/40%\;N_2$. Mushrooms packaged by the VM and PM methods developed a serious off-flavor after 2 days of storage, and a high stipe elongation rate after 5 days of storage, respectively. However, AM using 50% $CO_2/10%\;O_2/40%\;N_2$ of various gas ratios tested, allowed Enoki mushrooms to be maintained for up to 12 days without development of off-flavor, discoloration, or moldiness.

• Korean Journal of Environmental Biology
• /
• v.41 no.3
• /
• pp.179-192
• /
• 2023

In this study, changes in the microbial ecosystem of the Yeongheungdo island coastal waters were investigated for five years to collect basic data. To evaluate the influence of distance from the coast on the microbial ecosystem, four sites, coastal Site (S1) and 0.75, 1.5, and 3 km away from the coast, were set up and the changes in physicochemical and biological factors were monitored. The results showed seasonal changes in water temperature, dissolved oxygen, salinity, and pH but with no significant differences between sites. For nutrients, the concentration of dissolved inorganic nitrogen increased from 6.4 μM in April-June to 16.4 μM in July-November, while that of phosphorus and silicon phosphate increased from 0.4 μM and 2.5 μM in April-June to 1.1 μM and 12.0 μM in July-November, respectively. Notably, phosphorus phosphate concentrations were lower in 2014-2015 (up to 0.2 μM) compared to 2016-2018 (up to 2.2 μM), indicating phosphorus limitation during this period. However, there were no differences in nutrients with distance from the coast, indicating that there was no effect of distance on nutrients. Phytoplankton (average 511 cells mL^-1) showed relatively high biomass (up to 3,370 cells mL^-1) in 2014-2015 when phosphorus phosphate was limited. Notably, at that time, the concentration of dissolved organic carbon was not high, with concentrations ranging from 1.1-2.3 mg L^-1. However, no significant differences in biological factors were observed between the sites. Although this study revealed that there was no disturbance of the ecosystem, further research and more basic data on the microecosystem are necessary to understand the ecosystem of the Incheon.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.40 no.4
• /
• pp.391-402
• /
• 2014

In this study, the antioxidative effects and component analysis for the extracts of Rumex acetosa L. were investigated. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from dried R. acetosa L.. Free radical scavenging activities (1,1-diphenyl-2- picrylhydrazyl) size of, in the order of aglycone fraction > ethyl acetate fraction > 50% ethanol extract, aglycone fraction ($45.10{\mu}g/mL$) showed the highest radical scavenging activity. Reactive oxygen species (ROS) scavenging activity (total antioxidant capacity, $OSC_{50}$) on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system was also, in the order of ethyl acetate fraction> aglycone fraction> 50% ethyl acetate fraction, ethyl acetate fraction ($2.68{\mu}g/mL$) was shown a great antioxidant capacity. The total antioxidant capacity of the ethyl acetate fraction was found to be greater than L-ascorbic acid, known as a typical hydrophilic antioxidant ($6.88 {\mu}g/mL$). The cellular protective effects of R. acetosa L. extracts on the $^1O_2$-induced cellular damage of human erythrocytes were exhibited at all concentration-dependent ($1{\sim}25{\mu}g/mL$). Especially, aglycone fraction (${\tau}_{50}$, 104.80 min) in $25{\mu}g/mL$ showed the most protective effect among extracts. Components of the ethyl acetate fraction obtained from R. acetosa L. extracts were analyzed by TLC, HPLC chromatogram, LC/ESI-MS/MS. As a result, the ethyl acetate fraction contained several flavonoids, such as orientin, isoorientin, vitexin, isovitexin. These results indicate that the R. acetosa L. extracts can be used as antioxidants in biological systems, particularly skins exposed to UV radiation by quenching and/or scavenging $^1O_2$ and other ROS. Thus, the extracts of R. acetosa L. could be applicable to new anti-aging cosmeceutical ingredients.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.43 no.4
• /
• pp.309-320
• /
• 2017

In this study, the antioxidative effects and component analysis of 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from Annona muricata leaf were investigated. Free radical scavenging activities were performed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, total antioxidant capacities were estimated using luminol-dependent chemiluminescence assay and $^1O_2$ quenching effects were estimated. Free radical scavenging activities ($FSC_{50}$) of 50% ethanol extract, ethyl acetate fraction and aglycone fraction were 45.6, 29.8 and $18.0{\mu}g/mL$, and total antioxidant capacities ($OSC_{50}$) were 4.4, 1.1 and $2.8{\mu}g/mL$, respectively. As a result of $^1O_2$ quenching experiment, ethyl acetate and aglycone fraction showed similar activities to L-ascorbic acid used as a comparative control. The cellular protective effects of 50% ethanol extract on the $^1O_2-induced$ cellular damage of human erythrocytes were exhibited at concentration-dependent ($5-50{\mu}g/mL$). TLC and HPLC were used to analyse components in the ethyl acetate fraction and aglycone fraction of Annona muricata leaf. In ethyl acetate fraction, rutin (quercetin-3-O-rutinoside), kaempferol-3-O-neohesperidoside, nicotiflorin (kaempferol-3-O-rutinoside), p-coumaric acid were identified. In aglycone fraction, kaempferol was identified. These results suggest that the extracts of Annona muricata leaf have the applicability as antioxidant cosmeceutical ingredients.

• Korean Journal of Food Science and Technology
• /
• v.48 no.5
• /
• pp.508-514
• /
• 2016

Effects of the ethyl acetate fraction from gomchwi (Ligularia fischeri) extract against high $glucose/H_2O_2-induced$ oxidative stress and in vitro neurodegeneration were investigated to confirm the physiological property of the extract. The ethyl acetate fraction of gomchwi extract showed the highest total phenolic contents than the other solvent fractions. An anti-hyperglycemic activity of the ethyl acetate fraction was evaluated using the ${\alpha}-glucosidase$ inhibitory assay, and the half maximal inhibitory concentration ($IC_{50}$) value for ${\alpha}-glucosidase$ was found to be $727.64{\mu}g/mL$. In addition, the ethyl acetate fraction showed excellent 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt radical scavenging activity, and inhibition of malondialdehyde production. The ethyl acetate fraction also decreased intracellular reactive oxygen species, whereas neuronal cell viability against high glucose/$H_2O_2$-induced cytotoxicity was found to be increased. Finally, 3,5-dicaffeoylquinic acid as a main phenolic compound in the ethyl acetate fraction was analyzed by high-performance liquid chromatography. These results suggest that gomchwi might be a good natural source of functional materials to prevent diabetic neurodegeneration.

• Microbiology and Biotechnology Letters
• /
• v.39 no.1
• /
• pp.63-69
• /
• 2011

In this study, the antibacterial activity and the antioxidative effects, inhibitory effects on tyrosinase of Lespedeza cuneata G. Don extracts were investigated. MIC value of ethyl acetate fraction from L. cuneata G. Don on P. ovale (0.125%) showed that the antibacterial activity of the ethyl acetate fraction was higher than methyl paraben. The aglycone fraction of L. cuneata G. Don (14.63 ${\mu}g$/mL) showed the most prominent the free radical (1,1-diphenyl-2-picryl-hydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of L. cuneata G. Don fraction on $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The aglycone fraction of L. cuneata G. Don (0.07 ${\mu}g$/mL) showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of L. cuneata G. Don on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The L. cuneata G. Don extracts suppressed photohemolysis in a concentration dependent manner (1 ~ 50 ${\mu}g$/mL). The inhibitory effects ($IC_{50}$) of L. cuneata G. Don extracts on tyrosinase were determined with ethyl acetate fraction (104.83 ${\mu}g$/mL) and aglycone fraction (27.55 ${\mu}g$/mL) of L. cuneata G. Don extract. These results indicate that L. cuneata G. Don extract/fractions can function as high potential as bactericide against the pathogenic bacteria and antioxidant in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Extract/fractions of L. cuneata G. Don could be applicable to new functional cosmetics for antiaging, antioxidant, and antibacterial activity.

• Korean Chemical Engineering Research
• /
• v.43 no.6
• /
• pp.751-755
• /
• 2005

Carbon dioxide, included in the flue gas from the combustion of fossil fuel, was known as a representative green house gas and various removal and utilization technologies of it has been studied for the prevention of global warming. This study was performed as an effort to find out a method to reuse carbon dioxide separated from flue gas by magnetite powder. Magnetite powder was synthesized using various oxidizers and alkalinity controlled aqueous solutions of $FeSO_4{\cdot}7H_2O$ and NaOH at 50, 80, 90, $100^{\circ}C$ and analyzed by XRD and SEM. The analysis results showed that magnetite powder synthesized at higher alkalinity and temperature had crystalline spinel and cubic structure. The reduction by hydrogen and the oxidation by carbon dioxide of synthesized powder were studied by TGA. The results showed that magnetite powder synthesized at low alkalinity and temperature was non-cubical amorphous but crystalline and cubical at high alkalinity and temperature. Comparing magnetite powders synthesized using oxidants(air and oxygen) and nitrogen, magnetite powder using more oxygen containing oxidant synthesized more crystalline magnetite powder. The experimental results of redox reaction of the synthesized magnetite powder showed that the reduction by hydrogen and the oxidation by carbon dioxide were seldom observed below $400^{\circ}C$ and observed well at $500^{\circ}C$. Magnetite powder synthesized at $100^{\circ}C$ and alkalinity(molal concentration ratio of $FeSO_4{\cdot}7H_2O$ to NaOH) of 2.0 using $O_2$ showed the highest reduction of 27.15 wt％ and oxidation of 26.73 wt％, especially at reaction temperature of $500^{\circ}C$.

• Journal of Environmental Impact Assessment
• /
• v.26 no.6
• /
• pp.553-562
• /
• 2017

In these days, agricultural reservoirs are considered as a useful resource for recreational purposes, tour and cultural amenity for vicinity communities as well as irrigation water supply. However, many of the agricultural reservoirs are showing a eutrophic or hyper-eutrophic state and high level of organic contamination. In particular, about 44.7% of the aged agricultural reservoirs that constructed before 1945 exceed the water quality criteria for irrigational water use. In addition to external loading, internal nutrient loading from bottom sediment may play an important role in the nutrient budget of the aged reservoirs. The objectives of this study were to characterize variations of thermal structure of a shallow M reservoir (mean depth 1.7 m) and examine the potential of internal nutrient loading by continuous monitoring of vertical water temperature and dissolved oxygen (DO) concentration profiles in 2015 and 2016. The effect of internal loading on the total loading of the reservoir was evaluated by mass balance analysis. Results showed that a weak thermal stratification and a strong DO stratification were developed in the shallow M Reservoir. And, dynamic temporal variation in DO was observed at the bottom of the reservoir. Persistent hypoxic conditions (DO concentrations less than 2 mg/L) were established for 87 days and 98 days in 2015 and 2016, respectively, during the no-rainy summer periods. The DO concentrations intermittently increased during several events of atmospheric temperature drop and rainfall. According to the mass balance analysis, the amount of internal $PO_4-P$ loading from sediment to the overlying water were 37.9% and 39.7% of total loading during no-rainy season in 2015 and 2016, respectively on August when algae growth is enhanced with increasing water temperature. Consequently, supply of DO to the lower layer of the reservoir could be effective countermeasure to reduce nutrient release under the condition of persistent DO depletion in the bottom of the reservoir.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.34 no.2
• /
• pp.117-127
• /
• 2008

In this study, the antioxidative effects, inhibitory effects on elastase, and components of Cayratia japonica extracts were investigated. The free radical(1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities($FSC_{50}$) of extract/fractions of Cayratia japonica were in the order: 50% ethanol extract(114.3 ${\mu}g/mL$)${\mu}g/mL$)${\mu}g/mL$). Reactive oxygen species(ROS) scavenging activities($OSC_{50}$) of some Cayratia japonica extracts in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The order of ROS scavenging activities were deglycosylated flavonoid aglycone fraction($OSC_{50},\;3.30{\mu}g/mL$)<50% ethanol extract(1.21 ${\mu}g/mL$)${\mu}g/mL$). Ethyl acetate fraction showed the most prominent scavenging activity. The protective effects of extract/fractions of Cayratia japonica on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Cayratia japonica extracts suppressed photohemolysis in a concentration dependent manner($1{\sim}25{\mu}g/mL$), particularly deglycosylated flavonoid aglycone fraction exhibited the most prominent celluar protective effect(${\tau}_{50}$, 175.05min at 25 ${\mu}g/mL$). Aglycone fractions obtained from the deglycosylation reaction of ethyl acetate fraction among the Cayratia japonica extracts, showed 2 bands in TLC and 2 peaks in HPLC experiments(360 nm). Two components were identified as luteolin(composition ratio, 47.50%), apigenin(52.50). TLC chromatogram of ethyl acetate fraction of Cayratia japonica extract revealed 3 bands and HPLC chromatogram showed 4 peaks, which were identified as luteolin-7-O-${\beta}$-D-glucopyranoside(composition ratio, 11.14%), apigenin-7-O-${\beta}$-D-glucuronopyranoside(15.38%), luteolin(23.55%) and apigenin(49.92%) in the order of elution time. The inhibitory effect of aglycone fraction on elastase($IC_{50},\;70.5{\mu}g/mL$) was very high. These results indicate that extract/fractions of Cayratia japonica 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 Cayratia japonica extract and antioxidative effects could be applicable to new cosmetics.