• Journal of Plant Biology
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• v.5 no.4
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• pp.1-5
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• 1962

CHA, Jong Whan (Dept. of Biology, College of Education, Seoul National University). Effect of gibberallin on the growth and internal componsents of Astragalus sinicus L. Kor. Jour. Bot. V(4) : 1-5, 1962. The effect of GA on the growth as well as on the internal components of the leaves of Astragalus sinicus L. under the soil culture was investigated. The result has indicated that small variation in the relative concentration of GA treated on the leaves shows a marked influence on the internal components of the plants. The increase of growth was associated with increasing intensity of GA. Chlorophyll and carotene contents in the leaves were depressed with increasing concentration of GA. It was noticed that the growth was pomoted with the decrease of the contents of chlorophyll and carotene. In contrast the aacorbic acid in the leaves treated with GA decreased in proportion to the degree of the concentration of GA. Carotens content varied with chlorophyll, although the ratio of chlorophyll to carotene was not so high as the results obtained by Beck and Redman. Chlorophyll and ascorbic acid values with respect to growth differed greatly during the two experimental periods. The chlorophyll content was found highly significant in this experimental periods. The chlorophyll content was found highly significant in this experiment. As the concentration of GA was increased, it was noticed that there was a reduction of anthocyanin, sucrose, and reducing sugar contents. The anthocyanin content was not so high in this study as in the results obtained from the corn by Jacob Straus.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.335-339
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• 1999

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cylcic voltammetry. The voltammograms obtained could be classified ito 4 patterns (patterns 1-4). Patterns 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration ($IC_{50}$) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as patterns 4, showed the highest inhibitory activity (lowest $IC_{50}$ and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10-4 M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.4
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• pp.391-402
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• 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 Korean Society of Forest Science
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• v.96 no.5
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• pp.580-584
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• 2007

Actinidia arguta extracts obtained from three cultivars ('Sae-Han', 'Dae-Sung', and 'Chil-Bo') were assayed for their antioxidant properties and nutritional composition. Antioxidant activity of the extracts was evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Total phenolic contents of the extracts were determined by the Folin-Ciocalteu method. Vitamin C (L-ascorbic acid) content measured by a colorimetric method and reducing sugar content estimated by dinitrosalicylic acid (DNSA) method. Crude extracts from A. arguta 'Sea-Han' showed the most potent radical-scavenging activity showing 86.55% at 10 mg/ml. The DPPH radical scavenging activity of extracts and solvent fractions from Sea-Han cultivar was in decreasing order of EtOAc fraction>BuOH fraction>$CH_2Cl_2$ fraction>hexane fraction, among which EtOAc fraction showed the highest antioxidant activity (87.51 % at 5 mg/ml). Total phenolic contents in A. arguta 'Sae-Han', 'Dae-Sung' and 'Chil-Bo', were 32.93, 28.23, and 25.60 mg/g, respectively. Vitamin C contents of them were 840.57, 578.81 and 730.10 ug/g, respectively.

• Applied Biological Chemistry
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• v.13 no.2
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• pp.131-151
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• 1970

A new method of plastic film coating has been investigated to extend storage life of apples. The film coating was effected by dipping fresh apples in a plastic emulsion. The effect of plastic film coating on the preservation of freshness, respiratory activities and chemical components during storage, has been investigated on four leading varieties of apples. The results are summarized as follows: 1. The effect of film coating on storage life of apples was apparent, resulting in delay of after-ripening, shriveling, softening or physiological impediment as well as reducing consumption of reserve materials and waste fruits. 2. Change in the partial pressure of gas, i.e., increase in carbon dioxide and decrease in oxygen in apple tissue was resulted by the plastic film coating, suggesting that the film deposited on the fruit interfered with the diffusion of gases formed therein. 3. The effects of plastic film coating on the fruit storage varied with the type of plastic emulsions, coating temperature, varieties of apples and degree of fruit ripening. As regard to apple varieties, good results were obtained with PVA 217 for both American Summer Pearmain and Jonathan, and PVC 443 for McIntosh. 4. Reduction in the diminution rates of L-malic acid, ascorbic acid and soluble pectin etc. during storage of apples may account for the improved storage life of the fruits treated with plastic films.

• Korean Journal of Human Ecology
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• v.5 no.1
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• pp.85-93
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• 2002

This study was conducted to examine the effects of chitosan on the changes in physicochemical characteristics and hardness during Kimchi fermentation. The Kimchi samples were stored for 8 days at $20{\pm}l^{\circ}C$. The results were as follows : The pH value was decreased in order of Kimchi treated with 0.05% of 5% chitosan solution(chitosan 0.05%), Kimchi treated with 0.025% of 5% chitosan solution(chitisan 0.025%), Kimchi treated with 0.01% of 5% chitosan solution(chitosan 0.01%) and control, and the total acidity was increased in the opposed order. Volatile acid was increased like the total acidity, it was decreased after 6 days during fermentation, reducing sugar contents of Kimchi samples were decreased gradually. The ascorbic acid contents of Kimchi were increased rapidly in the early stage of fermentation and decreased in the late stage. Properties of hardness of Kimchi measured instrumentally were higher in the Kimchi treated with chitosan than control throughout the fermentation period.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.722-733
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• 2020

This study was aimed to investigate the physicochemical properties, texture, and antioxidant, and antimicrobial activities of regular-fat sausages (RFSs) mixed with 0.25 and 0.5% of oven-dried and freeze-dried grape tomato powder (GTP, 150 ㎛) during storage at 4℃. RFSs were made by six treatments that included: control (CTL), REF (sausages with 0.1% ascorbic acid alone), F1GTPSs (F1) and F2GTPSs (F2) (sausages with 0.25% and 0.5% freeze-dried GTP), and O1GTPSs (O1) and O2GTPSs (O2) (sausages with 0.25% and 0.5% GTP oven-dried at 100℃). Sausages with added oven-dried grape tomato powders (OGTPs) showed decreased pH, lightness (L^⁎), total plate count (TPC), and thiobarbituric acid-reactive substances (TBARS) compared to the sausages mixed with freeze-dried GTP (FGTPSs), but also had the highest redness (a^⁎) and yellowness (b^⁎) values among the treatments. With increasing levels of GTP, the hardness and chewiness of the sausages gradually decreased and these were decreased more in the FGTPSs (F) than in the OGTPSs (O). Compared to the FGTPSs, OGTPSs had higher antioxidant and antimicrobial activities, which extend the shelf-life of meat products. Application of OGTP to RFSs resulted in higher lipid antioxidant, antimicrobial activities, improving physicochemical properties and extended the shelf-life.

• Archives of Pharmacal Research
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• v.26 no.1
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• pp.24-27
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• 2003

A furanofuranoid lignan glycoside, with radical scavenging on peroxynitrite, total reactive oxygen species (ROS) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, was isolated from the rhizome of Salvia miltiorrhiza and characterized as (+)-1-hydroxypinoresinol-1-Ο-$\beta$-D-glucoside based on spectroscopic evidence. The compound exhibited peroxynitrite, total ROS and DPPH radical scavenging activities with $IC_{50}$ values of 3.23$\pm$0.04, 2.26$\pm$0.07 and 32.3$\pm$0.13 $\mu$M, respectively. Penicillamine, Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) and L-ascorbic acid, acting as positive controls, showed radical scavenging activities with $IC_{50}$ values of 6.72$\pm$0.25, 1.43$\pm$0.04 and 11.4$\pm$0.07 $\mu$M, respectively.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.699-706
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• 2006

The present study evaluated antioxidant and neuroprotective activities of hesperidin, a flavanone mainly isolated from citrus fruits, and its aglycone hesperetin using cell-free bioassay system and primary cultured rat cortical cells. Both hesperidin and hesperetin exhibited similar patterns of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. While hesperidin was inactive, hesperetin was found to be a potent antioxidant, inhibiting lipid peroxidation initiated in rat brain homogenates by $Fe^{2+}$ and L-ascorbic acid. In consistence with these findings, hesperetin protected primary cultured cortical cells against the oxidative neuronal damage induced by $H_2O_2$ or xanthine and xanthine oxidase. In addition, it was shown to attenuate the excitotoxic neuronal damage induced by excess glutamate in the cortical cultures. When the excitotoxicity was induced by the glutamate receptor subtype-selective ligands, only the N-methyl-D-aspartic acid-induced toxicity was selectively and markedly inhibited by hesperetin. Furthermore, hesperetin protected cultured cells against the $A_{{\beta}(25-35)}-induced$ neuronal damage. Hesperidin, however, exerted minimal or no protective effects on the neuronal damage tested in this study. Taken together, these results demonstrate potent antioxidant and neuroprotective effects of hesperetin, implying its potential role in protecting neurons against various types of insults associated with many neurodegenerative diseases.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.287-294
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• 2015

In this study, we investigated the antioxidative effects of brown seaweed Ecklonia cava extract and its subfractions. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction of E. cava. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) of ethyl acetate fraction ($FSC_{50}=6.98{\mu}g/mL$) and aglycone fraction ($7.03{\mu}g/mL$) are similar to that of (+)-${\alpha}$-tocopherol ($8.98{\mu}g/mL$) which is a reference control. Reactive oxygen species (ROS) scavenging activity (total antioxidant capacity, $OSC_{50}$) of the aglycone fraction ($OSC_{50}=14.48{\mu}g/mL$) on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay was the strongest among all extract and fractions. However, all samples showed lower antioxidant activities than that of L-ascorbic acid ($6.88{\mu}g/mL$) known as a powerful antioxidant. The protective effect of 50% ethanol extract on the $^1O_2$-induced cellular damage of human erythrocytes was dependent on the concentration from 5 to $50{\mu}g/mL$. Both ethyl acetate fraction and aglycone fraction showed strong cellular protective activities at $10{\mu}g/mL$, where the cellular protective effects (${\tau}_{50}$) of each fraction were recorded 442.0 min and 539.9 min, respectively. Three kinds of extract/fractions of E. cava showed much greater cellular protective activities at $10{\mu}g/mL$ than that of liposoluble antioxidant (+)-${\alpha}$-tocopherol (40.6 min) which is a reference control. These results suggest E. cava extracts and its fractions can be applied as an antioxidant ingredient in a field of cosmetics.