• Applied Biological Chemistry
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• v.37 no.3
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• pp.182-188
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• 1994

Similar to the $^{42}K$ uptake, $^{86}Rb$ uptake by the roots of Hordeum distichum grown in the hydroponic culture was negatively correlated with the concentration of K supplied previously, showing that $^{86}Rb$ can be used for the K-bioassay. $^{86}Rb$ having longer half life (18.86 day) than $^{42}K$ (12.36 hr) allowed the use of larger number of root samples. $^{86}Rb$ uptake of 3 years old Citrus unshiu Marc. grown in water culture decreased drastically with the increase of K concentration of the culture solution, thus demonstrating that the nutrition status of K for citrus trees can be diagnosed by K-bioassay using $^{86}Rb$ tracer. $^{86}Rb$ uptake by the excised roots of Hordeum distichum grown in the pot with different K fertilizations was well correlated with the exchangeable K in soil. The amount of exchangeable K in soil for the optimal plant growth can be determined by its relationship. $^{42}K$ and $^{86}Rb-uptake$ by the Hordeum distichum roots were markedly inhibited by $5{\times}10^{-3}\; M$ KCN in the bioassay solution, indicating that uptake is energy-dependent. There was no significant relationship between K content in citrus leaves and K concentration in the water-culture medium. It is concluded that K-bioassay is a potentially useful tool for determining of K requirement in citrus trees.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.415-421
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• 1997

The objectives of this study were to obtain standardized basic data on cambial electrical resistance (CER) of ornamental trees to be used for estimation of tree vigor and to compare CER between shrubs, deciduous, and coniferous trees in relation to bud opening, flowering, and growth cessation. Eighty healthy trees with four trees each for twenty ornamental tree species growing at an university campus in Suwon were selected and their CER was measured using a Shigometer every week from March to May, once a month from June to October and every two weeks in November, 1996. The CER of all tree species was high in March, started to decrease in April, maintained minimum in May through August, began to increase in September, and returned in November to the similar high level to March. Among the 20 species, Metasequoia glyptostroboides showed the lowest($5.5k{\Omega}$) annual average CER, while Cercis chinensis and Ligustrum obtusifolium had the highest($22.7k{\Omega}$, $22.9k{\Omega}$) annual average CER. The lowest CER($2.4k{\Omega}$) in summer(June through August) was obtained from Wisteria floribunda, second lowest($2.5k{\Omega}$) from Metasequoia glyptostroboides, the highest CER($46.8k{\Omega}$) during dormant season from Euonymus japonica, and second highest($45.0k{\Omega}$) obtained from Ligustrum obtusifolium. The CER of most species, particularly shrub species, started to decrease with bud opening, and many species, particularly shrubs and deciduous trees with large amount of flowers, showed sharp decrease with flowering. When CER was compared between shrubs and trees, shrubs showed higher average CER than trees, and seasonal difference in CER of evergreen species was smaller than that of deciduous species. It is interesting to note that the deciduous Metasequoia glyptostroboides had the lowest annual average CER.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.101-107
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• 2002

The essential oils isolated from leaves, flowers, stems, and fruits of Vitex rotundifolia by steam distillation and extraction (SDE) method were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 76 components detected by GC, 42 components were identified positively by GC-MS and GC co-injection with authentic standards, and 34 components were identified tentatively by mass spectral data only. They included 16 monoterpene hydrocarbons, 30 oxygenated hydrocarbons, 10 sesquiterpene hydrocarbons, 8 oxygenated sesquiterpenes, 3 diterpenes, and 9 miscellaneous components. The major components in the oil from the leaves were ${\alpha}-pinene$ (30.25%), 1,8-cineole (19.89%), sabinene (9.56%), ${\alpha}-terpineol$ (7.94%), ${\beta}-pinene$ (5.69%), and terpinen-4-ol (2.37%), and those in the flower oil were ${\alpha}-pinene$ (25.47%), 1,8-cineole (7.69%), manoyl oxide (6.21%), ${\beta}-pinene$ (4.20%), ${\alpha}-te.pineol$ (3.76%), and sabinene (2.78%). The major components in the oil from the stems were ${\alpha}-pinene$ (13.24%), ${\alpha}-terpineol$ (10.64%), 1,8-cineole (4.40%), manoyl oxide (4.02%), ${\beta}-pinene$ (2.39%), and terpinen-4-ol (2.21%) while those in the oil from the fruits were ${\alpha}-pinene$ (20.24%), 1,8-cineole (11.47%), ${\beta}P-pinene$ (9.79%), ${\alpha}-terpineol$ (7.08%), sabinene (3.68%), and limonene (2.77%). The percentage composition of monoterpenes in the oils from the leaves and the fruits were higher than in those from the flowers and the stems, whereas the oil from the flowers and the stems were characterized by a large content of sesquiterpenes, diterpenes and other unknown high molecular weight components.

• Applied Biological Chemistry
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• v.12
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• pp.25-31
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• 1969

The characteristics of crude enzyme produced from Trichoderma viride($O_2-1$) which isolated from half spoiled Locust acacia wood (Robinia Pseudacacia Linne) were examined in this paper. The results obtained were summarized as follows: 1) As a results of enzymatic action on several cellulose substrate it was found that there were some sorts of cellulase in crude enzyme. 2) The activity of C.M.C. ase and ${\beta}-glucosidase$ were decreased in accordance with increasing concentration of substrate, and filter paper saccharifying enzyme relatively increased in accordance with increasing concentration of substrate and enzyme in couse of time. 3) The optimal pH of each enzyme was 5.0 and the range of stability on pH generally from 3 to 6. 4) In disintegrating activity on filter paper, in decomposing activity on C.M.C. and $p-nitrophenyl-{\beta}-D-glucoside$, and in saccharifying activity on filter paper, the optimal temperatures were $50^{\circ}C.,\;60^{\circ}C,\;and\;65^{\circ}C$. 5) The order of stability on temperature was as follow; saccharifying activity on filter paper decomposing activity on C.M.C. disintegrating activity on filter paper>decomposing activity on $p-nitrophenyl-{\beta}-D-glucoside$. 6) The activity of the enzymes was inhibited with mercuric and silver ion, and activated with potassium.

• Journal of Life Science
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• v.22 no.6
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• pp.788-793
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• 2012

High concentration of antibiotics has been used to treat the outbreak of edwardsiellosis caused by Edwardsiella tarda in aquaculture. However, not all of the bacteria have been killed with high concentrations of antibiotics treatment by the formation of persister cells with a dormant state. The main objective of this study was to kill persister cell using antibiotics with the addition of natural plant compounds. Antibiotics used in this study consist of 100 mg/ml florfenicol and 100 mg/ml amoxicillin. Ten natural plant compounds with persister cell inhibitor activity to E. coli were obtained from Protein Engineering and Systems Biology Lab. of Sungkyunkwan University. The persister cell inhibition activities of those natural plant compounds were evaluated in test tube. Concentrations of the antibiotics were in the ranges of 25~200 ${\mu}g/ml$. The persister cell formation was observed after 16 hours of culture. Persister cells were killed by antibiotics with natural plant compounds. Among ten natural plant compounds, Gynostemma pentaphyllum, Mallotus japonicus, and Orixa japonica showed persister cell formation inhibition activities. The optimal concentrations of G. pentaphyllum, M. japonicus, and O. japonica for the inhibitor of persister cell formation were 100 ${\mu}g/ml$, 100 ${\mu}g/ml$, and 200 ${\mu}g/ml$, respectively. In vivo study was carried out to evaluate the effect of the antibiotics with natural plant compounds using aquacultural fish, olive flounder, as test animals. G. pentaphyllum, M. japonicus, and O. japonica of 30 ${\mu}g/ml$, 10 ${\mu}g/ml$, and 10 ${\mu}g/ml$ with antibiotics reduced cumulative mortalities, showing the effectiveness of persister cell inhibition.

• Journal of Life Science
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• v.30 no.8
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• pp.695-700
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• 2020

The purpose of this study is to evaluate the anti-oxidant and anti-microbial activity of syringin isolated from Cortex Fraxini to investigate their potential for use as safe natural compounds. Purified syringin was dissolved in distilled water for each concentration and used in each experiment. Syringin showed higher 2,2-Diphenyl-1-picrylhydrazyl radical scavenging than butylated hydroxytoluene (BHT) at a concentration of 50 ㎍/ml. In 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, activity was similar to that of BHT at all concentrations. In antioxidant protection factor measurement, activity of syringin slightly increased as the concentration increased, as did the inhibitory effect of thiobarbutric acid reactive substances. In evaluating anti-microbial activity, the clear zones of Listeria monocytogenes KCTC 13064, Staphylococcus aureus KCTC 1916, Escherichia coli KCTC 2571, and Helicobacter pylori HPKCTC B0150 at a concentration of 200 ㎍/ml were found to be 17.8 mm, 20.45 mm, 17.05 mm, and 16.8 mm, respectively, but no clear zone was observed in the case of Candida albicans ATCC 10231. The activity against water-soluble antioxidants was therefore superior to that against lipid-soluble antioxidants. Anti-microbial activity was examined by inhibiting growth against gram-positive and -negative strains, and anti-fungal activity was not observed. Based on the results of this study, syringin has possible applications as a natural anti-oxidant and anti-microbial material.

• Journal of Life Science
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• v.25 no.5
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• pp.515-522
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• 2015

Treculia africana Decne, a breadfruit species, is native to many parts of West and Tropical Africa. The breadfruit belongs to the family Moraceae and is one of the four members of the genera Treculia. The crude extract of T. africana has been used in folk medicine as an anti-inflammatory agent for various ailments, such as whooping cough. In this study, we evaluated the anti-oxidative and anti-cancer activities of the methanol extract of T. africana Decne (META) and the molecular mechanisms of its anti-cancer effects in human colon carcinoma HT29 cells. The META exhibited anti-oxidative activity through a DPPH radical scavenging capacity and inhibited cell growth in a dose-dependent manner in HT29 cells. META treatment induced apoptosis of HT29 cells, showing an increase in the percentage of both SubG1 cells and Annexin V-positive cells and the formation of apoptotic bodies in a dose-dependent manner. META-mediated apoptosis was associated with the up-regulation of the death receptor FAS and Bax and a decrease in the Bcl-2 expression. META-treated HT29 cells also showed the release of cytochrome c from the mitochondria into the cytosol, activation of caspase-3, caspase-8, and caspase-9, and proteolytic cleavage of poly ADP-ribose polymerase (PARP). These findings suggest META may exert an anti-cancer effect in HT29 cells by inducing apoptosis through both intrinsic and extrinsic pathways.

• Journal of Life Science
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• v.27 no.5
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• pp.536-544
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• 2017

Abeliophyllum distichum Nakai is deciduous shrubs of flowering plant in Oleaceae. It is important plant resources and consists of one species in the world. Also the endemic plant of A. distichum has been protected and designed endangered plant in Korea. For this reason, study on the immature seeds of A. distichum (ADS) hasn't progressed. In the present study, we evaluated the antioxidant activity and inhibitory effects on proteins and mRNA levels were related in the whitening effect in B16F10 cells. ADS was effective for reaction oxygen species (ROS). ROS causes various diseases such as aging, inflammation, cancer, and etc. Antioxidant properties were evaluated DPPH, ABTS radical scavenging activity and Reducing power. Plants were known that contained phenolic compounds were related in antioxidant activity. Phenolic compounds were phytochemicals commonly named natural polyphenols. These are secondary metabolites of plants involved in the defense against different types of stresses. In results, ADS suppressed the expression and transcription of Tyrosinase, TRP-1, TRP-2, and Microphthalmia-associated transcription factor (MITF). Tyrosinase, tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 1 (TRP-2) are known to play an important role in melanin biosynthesis. MITF regulated the expression and transcription of Tyrosinase, TRP-1, and TRP-2. In conclusion, ADS was effective in both antioxidant activities and whitening effects. Also, they were associated with the content of phenolic compounds. We suggested that ADS can be use antioxidants and skin-whitening functional cosmetics material derived from natural plant resources.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.208-217
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• 2023

Accurate estimation of dormancy breaking and first bloom dates is crucial for effective fire blight control by disease model such as Maryblyt in apple orchards. The duration from dormancy breaking to first bloom in apple trees was influenced by daily minimum temperatures during the dormant period. The purpose of this study is to investigate the relationship between minimum temperatures during this period and the time taken for flowering to commence. Webcam data from eight apple orchards, equipped by the National Institute of Horticultural and Herbal Science, were observed from 2019 to 2023 to determine the dates of starting bloom (B1). Additionally, the dormancy breaking dates for these eight sites were estimated using an apple chill day model, with a value of -100.5 DD, based on collected weather data. Two regressions were performed to analyze the relationships: the first regression between the number of days under 0℃ (X₁) and the time from calculated dormancy breaking to observed first bloom (Y), resulting in Y = 0.87 × X₁ + 40.76 with R² = 0.84. The second regression examined the starting date of breaking dormancy (X₂) and the duration from dormancy breaking to observed first bloom (Y), resulting in Y = -1.07 × X₂ + 143.62 with R² = 0.92. These findings suggest that apple anti-chill days are significantly affected by minimum temperatures during the period from dormancy breaking to flowering, indicating their importance in fire blight control measures.

• Journal of Life Science
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• v.31 no.9
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• pp.827-833
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• 2021

Dendropanax morbiferus leaves (DPL) has been used as a medicine since ancient times in various diseases such as inflammation, diabetes, and cancer. In particular, it has been found to have anticancer effects on several types of cancer cells, but the anticancer effect on breast cancer cells SK-BR-3 has not yet been revealed. Therefore, in this study, DPL caused proliferation inhibition in breast cancer cells SK-BR-3 and the anticancer effect by inducing apoptosis was confirmed, through an in vitro experiment. In order to examine the effect of DPL on cell viability, MTT assay was performed to confirm a significant decrease in the concentration of cell viability. DAPI staining was performed to examine the effect of DPL on cellular morphological changes and increase of apoptotic bodies. To supplement this, an increase in the apoptosis rate was also confirmed through flow cytometry after staining with annexin V/PI. Western blot was performed to confirm apoptosis-related proteins. DPL increased the expression of Cleaved-PARP, Bax whereas decreased the expression of Bcl-2. Changes in the expression levels of MAPK pathway proteins p-ERK1/2, p-JNK, and p-p38 were also confirmed, and a significant increase in p-p38 was observed. These results indicated that DPL induced apoptosis, through p-p38 MAPK signal pathway in SK-BR-3 breast cancer cells.