• Journal of Sericultural and Entomological Science
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• v.47 no.2
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• pp.62-67
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• 2005

Much attention has been focused on the activity of the natural antioxidants present in fruits and vegetables, because potentially these components may reduce the level of oxidative stress. Especially, mulberry leaves containing many natural components are considerable resource far natural antioxidants. The antioxidant capacity of mulberry leaves was investigated with minilum L-100 device and ARAW-KIT (anti-radical ability of water-soluble substance), in comparison to the ascorbic acid. The appropriate conditions for pre-treatments of mulberry leaves were 80% MeOH, 30 sec. vortex mixing. The antioxidant capacity of 16 varieties was 3303.4 nmol (ascorbic acid equivalents) at opening stage of five leaves in spring. The highest stage of antioxidant capacity (3708.0 nmol) and yield rate was just before the coloration stare with anthocyanin in fruits, whereas the lowest stage was middle of June (2231.6 nmol) and about two months growing stage after summer pruning (2064.6 nmol). But after summer pruning, the antioxidant capacity of mulberry.

• The Korea Journal of Herbology
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• v.31 no.3
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• pp.43-48
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• 2016

Objectives : The objective of this research was to investigate the antioxidant activities of stem bark of Maackia amurensis extract.Methods : Stem bark of Maackia amurensis extract were prepared using 70% methanol. Methanol extracts were fractionated to hexane, chloroform, ethyl acetate, butyl alcohol, water fractions and investigated. The antioxidant activities of fractions was evaluated by four different assays as total polyphenol contents, total flavonoid contents, DPPH(1,1-diphenyl-2-picrylhydrazyl) free-radical scavenging activity and ABTS(2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging ability.Results : The yield of methanolic extracts from stem bark of Maackia amurensis was 10.16%, whereas those of its solvent fractions (hexane, chloroform, ethyl acetate, butyl alcohol, and water) were 5.45, 11.39, 13.88, 26.07, and 40.80%, respectively. The total polyphenol contents and electron donating ability of 70% methanol extracts from stem bark of Maackia amurensis were 15.44 mg/g and 194.15 μg/mL of its IC₅₀, respectively. The 70% methanol extracts showed the highest antioxidant activity. The total polyphenol content and total flavonoid content of chloroform fractions were higher in each of 201.98 mg/g and 13.55 mg/g. The chloroform fraction showed the lowest levels of DPPH(IC₅₀, 183.95 μg/mL) and ABTS scavenging activity(IC₅₀, 10.0 μg/mL). The antioxidant activity was detected in methanol extract, chloroform fractions.Conclusions : These results indicate that 70% methanol extract and its fractions of stem bark of Maackia amurensis, especially chloroform fraction, have the properties of anti-oxidant suggesting stem bark of Maackia amurensis may be a candidate for natural and functional materials.

• 한국정보교육학회:학술대회논문집
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• 2011.01a
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• pp.29-35
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• 2011

With the society rapidly changing, children are being asked respond quickly to these changes. Therefore, how children learn and think comes before what to teach, and we need to come up with ways to nurture their ability to proactively control their lives and studies. We attempt to use the technique of Accelerated learning, which focuses on the student's own ability toacquire and use information, to enhance the efficiency of information technology education. We designed the PLAY model based on accelerated learning and Multiple Intelligence Theory, and conducted ten experimental sessions on two groups of 70 second grade elementary school students.

• KSBB Journal
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• v.28 no.5
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• pp.295-302
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• 2013

Indigo is utilized in various industries including textile dyeing, cosmetics, printing and medicinal products and its reduced form, leuco-indigo, is mainly used in these process. Chemical reducing agent (sodium dithionite, sodium sulfide, etc.) is preferred to use for the formation of leucoindigo in industry. In traditional indigo fermentation process, microorganisms can participate in the reduction of indigo and thus it has been known to reduce environmental pollution and noxious byproducts. However, in fermentation method using microorganisms it is difficult to standardize large scale production process due to low yield and reproducibility. In this study, we attempted to develop the indigo reduction process using microbial flora which was isolated from naturally fermented indigo vat or deduced by metagenomic approach. From the results of library analyses of PCR-amplified 16S rRNA genes from the traditional indigo fermentation vat sample (metagenome), it was confirmed that Alkalibacteriums (71%) was distinctly dominant in population. Some strains were identified after confirming that they become pure culture in nutrient media modified slightly. Four strains were separated in this process and each strain showed obvious reducing ability toward indigo in dyeing test. It is expected that the analyzed results will provide important data for standardizing the natural fermentation of indigo and investigating the mechanism of indigo reduction.

• Toxicological Research
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• v.26 no.4
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• pp.321-327
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• 2010

The ability of 80% ethanol extracts from five medicinal plants, Aralia continentalis, Paeonia suffruticosa, Magnolia denudata, Anemarrhena asphodeloides, and Schizonepeta tenuifolia, to neutralize hydroxyl radical, peroxyl radical and peroxynitrite was examined using the total oxyradical scavenging capacity (TOSC) assay. Peroxyl radical was generated from thermal homolysis of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (ABAP); hydroxyl radical by an iron-ascorbate Fenton reaction; peroxynitrite by spontaneous decomposition of 3-morpholinosydnonimine N-ethylcarbamide (SIN-1). The oxidants generated react with $\alpha$-keto-$\gamma$-methiolbutyric acid (KMBA) to yield ethylene, and the TOSC of the substances tested is quantified from their ability to inhibit ethylene formation. Extracts from P. suffruticosa, M. denudata, and S. tenuifolia were determined to be potent peroxyl radical scavenging agents with a specific TOSC (sTOSC) being at least six-fold greater than that of glutathione (GSH). These three plants also showed sTOSCs toward peroxynitrite markedly greater than sTOSC of GSH, however, only P. suffruticosa revealed a significant hydroxyl radical scavenging capacity. Seven major active constituents isolated from P. suffruticosa, quercetin, (+)-catechin, methyl gallate, gallic acid, benzoic acid, benzoyl paeoniflorin and paeoniflorin, were determined for their antioxidant potential toward peroxynitrite, peroxyl and hydroxyl radicals. Quercetin, (+)-catechin, methyl gallate, and gallic acid exhibited sTOSCs 40~85 times greater than sTOSC of GSH. These four components also showed a peroxynitrite scavenging capacity higher than at least 10-fold of GSH. For antioxidant activity against hydroxyl radical, methyl gallate was greatest followed by gallic acid and quercetin. Further studies need to be conducted to substantiate the significance of scavenging a specific oxidant in the prevention of cellular injury and disease states caused by the reactive free radical species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.732-736
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• 2000

The purpose of this study was to investigate the extraction method of phenolic compounds and antioxidant activities of the aerial part of Epimedium koreanum NAKAI (EKN). The antioxidant activities of EKN were tested with by hydrogen donating ability, inhibition of lipid peroxidation, and inhibition of LDL oxidation. The most suitable conditions for the extraction of phenolic compounds from EKN were to use 60% ethanol by 3 times, and the yield of extract (dry basis) was 22%. In the extraction efficiency of phenolic compounds, 60% ethanol as extracting solvent was superior to water. Sixty% ethanol extract of EKN was found to have an ability of hydrogen donating to DPPH. MDA determination showed the 95% inhibitory effect against linoleic acid oxidation by the addition of 700 ppm EKN extract. Also, about 70% of LDL oxidation was inhibited by the addition of 500 ppm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.26-31
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• 2000

This study was carried out to obtain the basic information for breeding cold-tolerant rice varieties with high yield-productivity through wide crosses between indica and japonica rice. Genetic analysis was conducted using 55 F$_1$s obtained from half-diallel crosses among eleven cultivars of various origin including indica and japonica rice. Screening for cold tolerance was done with cold-water irrigation after transplanting until ripening stage. Both general combining ability (GCA) and specific combining ability (SCA) effects were highly significant in all characters associated with dry matter accumulation at 30 and 50days after cold-water irrigation (DAC). The variance of GCA was much larger than that of SCA in plant height, shoot dry weight per plant (DWP), crop growth rate (CGR) and cold-water response index (CRI) of these characters except CRI of shoot dry weight per plant. The DWP, CGR and CRI of these characters of Gaochan 102, Tong88-7 and TR22183 were markedly higher than those of the others. GCA effects of these varieties on DWP, CGR and their CRI were also higher than those of the others, indicating that they are useful as promising parents for breeding cold-tolerant varieties. Analysis of genetic parameters for 11$\times$11 half-diallel F$_1$s revealed that inter-locus gene interaction were concerned in the expression of plant height at 50 DAC, CRI of DWP at 50 DAC, and CRI of CGR, and that intra-locus gene interaction for plant height and the other characters were partial dominance and over-dominance, respectively. Narrow-sense heritability (h$^2$$_{N}$) was the highest in plant height as 0.729, and the lowest in CRI of DWP at 30 DAC as 0.048, suggesting that selection for cold tolerance will be quite effective in case that the selection criterion is the performance itself.f.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.25-31
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• 1975

In order to increase the rate of ripening during the grain-forming stage the partial dressing was introduced with the ordinary dressing comparatively. Two different rice varieties, Bong-kwang(early) and Nong-kwang (moderate), grown at the fine sand alluvial soil of River, Han Kimpo, were investigated. To evaluate the photosynthetic ability of these treatments assimilation rate of Carbon-14 was effectively carried out with the active leaves of rice at the maturing stage, and the inorganic constituents of leaves, stem, leaf sheath and grain were analyzed. All the data on the photosynthetic ability, inorganic constituent and yield determining were discussed with the point of continual phloem translocation between those plant organs.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.567-573
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• 2010

To ascertain the effect of over-expressed maize calreticulin in tomato plant on tobamovirus movement in addition to validating potentiality of the gene (ZmCRT) as a means for the virus-resistance resource, four ZmCRT-expressing homozygous lines were generated from the T0 plants as using an Agrobacterium-mediated transformation, nucleic acid analyses, and a conventional breeding method. Of them, a line was subjected to the bioassay for tolerances to tobacco mosaic virus-U1 (TMV-U1) and tomato mosaic virus (ToMV) followed by RT-PCR and a chlorophyll fluorescence quenching analyses. Both transgenic plants transcribing ZmCRT and wild-type plants showed no symptom by 20 days after viruses inoculation, however the photosystem II quantum yield parameter measured from the upper leaves of ToMV-inoculated plants revealed that ZmCRT transgenic plants have higher photosynthetic ability than wild-type ones at that time, which indirectly implies that over-expressed ZmCRT product acts as a barrier to the cell-to-cell and/or systemic movement of ToMV. Moreover, ZmCRT transgenic plants showed remarkably longer shoot length than wild-type ones in 40 days after TMV-U1 or ToMV inoculation each, which might be resulted from higher photosynthetic ability during the phase not yet showing any external symptoms. Collectively, over-expressed ZmCRT protein in tomato plants is able to interrupt the systemic movement of infected TMV-U1 and ToMV even though not perfect.

• Food Science of Animal Resources
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• v.21 no.1
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• pp.1-9
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• 2001

This study was carried out to investigate the extraction yield, the contents of total phenol substances and antioxidative substances, electron donating abilities, nitrite scavenging abilities of water and ethanol extracts from Cassia tora L. and Pueraria thunbergiana and antioxidative activity of water and ethoanol extract from Cassia tara L. Tatal phenol substances of water and ethanol extract from Cassia tora L. and Pueraria thunbergiana showed nearly the same levels, and the antioxidative substances of water and ethanol extract from Pueraria thunbergiana has as much as two times higher than those from Cassia tara L.. The nitrite scavenging abilities were measured at pH 1.2, 3.0, 4.2 and 6.0, respectively. Water and ethanol extracts from Cassia tora L showed 14.9%∼22.3% and 49.1%∼56.7%, and those from Pueraria thunbergiana revealed 57.7%∼61.0% of nitrite scavenging abilities, respectively. Especially the extracts from Pueraria thunbergiana showed higher pH dependence than those from Cassia tora L. The electrol donating abilities of water extract from Cassia tora L. were higher than those from Pueraria thunbergiana, and vice versa in the case of ethanol extracts. In the antioxidative activitiy of extracts from Cassia tora L. against linoleic acid during storage of 20 days at 50$^{circ}C$, peroxide values at the addition level of 5mg and 10mg were consoderably lower than 2mg although peroxide value increased above 375 after 12days of storage compared with the control(BHA-added) of 129 at 8days.