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Search Results: 1 - 10 of 53329 matches for " Sun-Ju Kim "
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Cultivation characteristics and flavonoid contents of wormwood (Artemisia montana Pamp.)  [PDF]
Yong Joo Kim, Jeong-Hoon Lee, Sun-Ju Kim
Journal of Agricultural Chemistry and Environment (JACEN) , 2013, DOI: 10.4236/jacen.2013.24017
Abstract: The aim of this study was to establish the optimum harvesting time and the content of flavonoids in the leaves, stems, and roots of Artemisia montana Pamp. A. montana was monitored from June to October in 2012. The yield of A. montana at high density (30 × 10 cm) was higher than that of A. montana at low density (30 × 20 and 30 cm). Yield in terms of dry weight was increased with an extended growth period and development stage. High yield achieved at 2580 and 2757 kg?10 a?1 in September and October, respectively. Among the leaves, stems, and underground plant organs, jaceosidin and eupatilin were mainly detected in the leaves, and the highest levels were observed in June, at values of 66.6 and 158.2 mg?100 g?1, respectively. In contrast, apigenin was the major compound detected in the underground plant organs, with levels ranging from 21.2 to 29.5 mg?100 g?1 until September. Therefore, optimal harvest times were between September and October, generating a high yield and adding economic value although a higher level of total flavonoids was observed in crops harvested in June.
Isolation and identification of alkaloids and anthocyanins from flower and bulb of Lycoris radiata using HPLC and LC-ESI-MS  [PDF]
Jin-Hyuk Chun, In Hyuk Jang, Mariadhas Valan Arasu, Naif Abdullah Al-Dhabi, Veeramuthu Duraipandiyan, Dong-Hoon Lee, Sanghyun Lee, Sun-Ju Kim
Journal of Agricultural Chemistry and Environment (JACEN) , 2013, DOI: 10.4236/jacen.2013.21004
Abstract: Three anthocyanins (cyanidin 3-diglucoside, cyanidin 3-sambubioside and cyanidin 3-glucoside) together with eleven known alkaloids (lycoricidine, hipppeastrine,O-Demethyllycoramin, lycoricidinol, galanthine, lycorine, lycorenine, lycoramine, galanthamine, homolycorine and pretazettine) were identified in the flower and bulb of Lycoris radiata using high-performance liquid chromatography coupled with UV detection and electrospray ionization mass spectrometry. Anthocyanins play a major role in protecting plant’s DNA from the UV spectrum of sunlight and also in attracting insects for the purpose of pollination. Thus, knowledge on the contents and types of anthocyanins of L. radiata will help to evaluate the adaptive evolution of flowers and provide useful information for the ornamental breeding.
Quantitative differentiation of phenolic compounds in different varieties of buckwheat cultivars from China, Japan and Korea  [PDF]
Jeong Min Seo, Da Bin Lee, Mariadhas Valan Arasu, Qi Wu, Tatsuro Suzuki, Young-Ho Yoon, Sang-Won Lee, Sang Un Park, Sun-Ju Kim
Journal of Agricultural Chemistry and Environment (JACEN) , 2013, DOI: 10.4236/jacen.2013.24016
Abstract: The aim of this study was to determine the variation of phenolic compounds in common and tartary buckwheats collected from China, Japan and Korea. Two buckwheat varieties of each country were cultivated using nutrient solution and vermiculite in the greenhouse from February to May, 2012 and harvested at two-week intervals. Phenolics such as chlorogenic acid, C-glycosylflavones (orientin, isoorientin, vitexin, and isovitexin), rutin, and quercetin were quantified using high performance liquid chroma-tography (HPLC). At 17, 29, 44, 58, and 72 days after sowing (DAS), before harvesting each organs, rutin content of cultivars from China and Korea at 17 DAS was the highest (mean 43.63 and 39.95 mg?g–1 DW, respectively) than that of 29 and 44 DAS. However, two varieties from Japan at 44 DAS were documented maximum; whereas, the amount of rutin in “Hokkai T10” harvested at 44 DAS (58.36 mg?g–1 DW) was the highest of all cultivars. Rutin level in the leaves and stems at 72 DAS were comparatively higher than at 58 DAS. The highest of rutin content was found at 72 DAS (73.33 mg?g–1 DW) in “Hokkai T10” leaves followed by “Daegwan No.3-3” (61.13 mg?g–1 DW), “rice tartary” (53.89 mg?g–1 DW). Rutin content of flowers was presented as the highest amount in “Hokkai T10” at 72 DAS (88.3 mg?g–1 DW) was approximately 14-fold higher than that of 58 DAS (6.44 mg?g–1 DW). However, rutin content of flower in “Xiqiao No.2” was 3-fold higher at 72 DAS than at 58 DAS. Rutin and total phenolic compounds content in flowers, leaves, and stems were higher in the order. The content of four C-glycosylflavones in common buckwheat was higher than those in tartary buckwheat, but rutin content which accounted >90% of the total phenolic compounds was higher in tartary buckwheat. The highest amounts of chlorogenic acid and quercetin were measured in the flower of “Xiqiao No.2” (6.85 and 11.69 mg?g–1 DW, respectively). Based on these results, the presence of different phenolic compounds in all the varieties of buckwheat confirmed that it can be regarded as a potent source of functional foods.
Identification and Determination of Phenolic Compounds in Rapeseed Meals (Brassica napus L.)  [PDF]
Si-Chang Yang, Mariadhas Valan Arasu, Jin-Hyuk Chun, Young-Seok Jang, Yong-Hwa Lee, In Ho Kim, Ki-Taek Lee, Soon-Taek Hong, Sun-Ju Kim
Journal of Agricultural Chemistry and Environment (JACEN) , 2015, DOI: 10.4236/jacen.2015.41002
Abstract: This study aimed in the identification and quantification of phenolic compounds in different four varieties of rapeseeds (Brassica napus L.) using LC-MS and HPLC. LC-MS analysis guided to identify 12 phenolic compounds including sinapine, sinapine(4-O-8')guaiacyl, feruloyl choline(4-O-8') guaiacyl, kaempferol-3-O-sinapoyl-sophoroside-7-O-glucoside, kaempferol-3-O-β-sophoroside, cyclic spermidine-alkaloid, feruloyl choline(5-8')guaiacyl, kaempferol-sinapoyl-trihexoside,1,2-di- O-sinapoyl-gentiobiose, 1,2-di-O-sinapoyl-glucose, feruloyl choline(4-O-8')guaiacyl-di-sinapoyl, and sinapine(4-O-8')guaiacyl-di-sinapoyl, respectively. Total phenolic compounds in rapeseed meals were ranged from 38.50 (2012 “Sunmang”) to 63.95 mg/g dry weight (DW) (2014 Jeju local cultivar). Main phenolic compositions were cyclic spermidine-alkaloid, kaempferol, feruloyl choline, and sinapine. Sinapine was predominant compound among all the samples ranged from 29.74 to 52.24 mg/g DW (mean 79% of total phenolic contents). This study provided the information for the variation of phenolic compounds between the varieties of rapeseeds and the cultivation periods. Furthermore, this information can be developed for bio-energy industry as a reducer of the cost of the bio-energy products.
Characterization of the Resonant Caustic Perturbation
Sun-Ju Chung
Physics , 2009, DOI: 10.1088/0004-637X/705/1/386
Abstract: Four of nine exoplanets found by microlensing were detected by the resonant caustic, which represents the merging of the planetary and central caustics at the position when the projected separation of a host star and a bounded planet is s~1. One of the resonant caustic lensing events, OGLE-2005-BLG-169, was a caustic-crossing high-magnification event with $A_{max} \sim$ 800 and the source star was much smaller than the caustic, nevertheless the perturbation was not obviously apparent on the light curve of the event. In this paper, we investigate the perturbation pattern of the resonant caustic to understand why the perturbations induced by the caustic do not leave strong traces on the light curves of high-magnification events despite a small source/caustic size ratio. From this study, we find that the regions with small-magnification-excess around the center of the resonant caustic are rather widely formed, and the event passing the small-excess region produces a high-magnification event with a weak perturbation that is small relative to the amplification caused by the star and thus does not noticeably appear on the light curve of the event. We also find that the positive excess of the inside edge of the resonant caustic and the negative excess inside the caustic become stronger and wider as $q$ increases, and thus the resonant caustic-crossing high-magnification events with the weak perturbation occur in the range of $q \leqslant 10^{-4}$. We determine the probability of the occurrence of events with the small excess $|\epsilon| \leqslant 3 %$ in high-magnification events induced by a resonant caustic. As a result, we find that for the Earth-mass planets with a separation of ~ 2.5 AU, the resonant caustic high-magnification events with the weak perturbation can occur with a significant frequency.
MYB Transcription Factors Regulate Glucosinolate Biosynthesis in Different Organs of Chinese Cabbage (Brassica rapa ssp. pekinensis)
Yeon Bok Kim,Xiaohua Li,Sun-Ju Kim,Haeng Hoon Kim,Jeongyeo Lee,HyeRan Kim,Sang Un Park
Molecules , 2013, DOI: 10.3390/molecules18078682
Abstract: In this study, we investigated the expression of seven MYB transcription factors (a total of 17 genes that included Dof1.1, IQD1-1, MYB28, MYB29, MYB34, MYB51, and MYB122 and their isoforms) involved in aliphatic and indolic glucosinolate (GSL) biosynthesis and analyzed the aliphatic and indolic GSL content in different organs of Chinese cabbage ( Brassica rapassp. Pekinensis). MYB2 8 and MYB2 9 expression in the stem was dramatically different when compared with the levels in the other organs. MYB34, MYB122, MYB51, Dof1.1, and IQD1-1 showed very low transcript levels among different organs. HPLC analysis showed that the glucosinolates (GSLs) consisted of five aliphatic GSLs (progoitrin, sinigrin, glucoalyssin, gluconapin, and glucobrassicanapin) and four indolic GSLs (4-hydroxyglucobrassicin, glucobrassicin, 4-methoxygluco-brassicin, and neoglucobrassicin). Aliphatic GSLs exhibited 63.3% of the total GSLs content, followed by aromatic GSL (19.0%), indolic GSLs (10%), and unknown GSLs (7.7%) in different organs of Chinese cabbage. The total GSL content of different parts (ranked in descending order) was as follows: seed > flower > young leaves > stem > root > old leaves. The relationship between GSLs accumulation and expression of GSLs biosynthesis MYB TFs genes in different organs may be helpful to understand the mechanism of MYB TFs regulating GSL biosynthesis in Chinese cabbage.
Bcr is a substrate for Transglutaminase 2 cross-linking activity
Sun-Ju Yi, John Groffen, Nora Heisterkamp
BMC Biochemistry , 2011, DOI: 10.1186/1471-2091-12-8
Abstract: We here report that activation of TG2 by calcium caused the formation of covalently cross-linked Bcr. Abr, a protein related to Bcr but lacking its N-terminal oligomerization domain, was not cross-linked by TG2 even though it forms a complex with it. A Bcr mutant missing the first 62 amino acid residues remained monomeric in the presence of activated TG2, showing that this specific domain is necessary for the cross-linking reaction. Calcium influx induced by a calcium ionophore in primary human endothelial cells caused cross-linking of endogenous Bcr, which was inhibited by the TG2 inhibitor cystamine. Treatment of cells with cobalt chloride, a hypoxia-mimetic that causes cellular stress, also generated high molecular weight Bcr complexes. Cross-linked Bcr protein appeared in the TritonX-100-insoluble cell fraction and further accumulated in cells treated with a proteasome inhibitor.Bcr thus represents both an interacting partner under non-stressed conditions and a target of transglutaminase activity for TG2 during extreme stress.The breakpoint cluster region (Bcr) protein was originally identified as the amino-terminal part of a fusion protein including the Abl tyrosine kinase, which causes chronic myeloid leukemia and Ph-chromosome-positive acute lymphoblastic leukemia. The fusion of Bcr to Abl deregulates the tyrosine kinase activity of Abl [1]. Although the Bcr protein contributes a varying number of domains to the fusion protein, the N-terminal oligomerization domain of Bcr is considered to be the most critical component that allows the formation of homo-tetramer Bcr/Abl complexes and deregulates the Abl tyrosine kinase [2,3].The normal (non-rearranged) BCR gene encodes a multidomain protein. Apart from the oligomerization domain, it additionally contains serine/threonine protein kinase, tandem DH-PH, C2 and GTPase activating protein (GAP) domains. The latter domain has a relatively well-described function: it down-regulates the activated GTP-bound conformation
Expression of cassini, a murine gamma-satellite sequence conserved in evolution, is regulated in normal and malignant hematopoietic cells
Arutyunyan Anna,Stoddart Sonia,Yi Sun-ju,Fei Fei
BMC Genomics , 2012, DOI: 10.1186/1471-2164-13-418
Abstract: Background Acute lymphoblastic leukemia (ALL) cells treated with drugs can become drug-tolerant if co-cultured with protective stromal mouse embryonic fibroblasts (MEFs). Results We performed transcriptional profiling on these stromal fibroblasts to investigate if they were affected by the presence of drug-treated ALL cells. These mitotically inactivated MEFs showed few changes in gene expression, but a family of sequences of which transcription is significantly increased was identified. A sequence related to this family, which we named cassini, was selected for further characterization. We found that cassini was highly upregulated in drug-treated ALL cells. Analysis of RNAs from different normal mouse tissues showed that cassini expression is highest in spleen and thymus, and can be further enhanced in these organs by exposure of mice to bacterial endotoxin. Heat shock, but not other types of stress, significantly induced the transcription of this locus in ALL cells. Transient overexpression of cassini in human 293 embryonic kidney cells did not increase the cytotoxic or cytostatic effects of chemotherapeutic drugs but provided some protection. Database searches revealed that sequences highly homologous to cassini are present in rodents, apicomplexans, flatworms and primates, indicating that they are conserved in evolution. Moreover, CASSINI RNA was induced in human ALL cells treated with vincristine. Surprisingly, cassini belongs to the previously reported murine family of γ-satellite/major satellite DNA sequences, which were not known to be present in other species. Conclusions Our results show that the transcription of at least one member of these sequences is regulated, suggesting that this has a function in normal and transformed immune cells. Expression of these sequences may protect cells when they are exposed to specific stress stimuli.
Properties of Microlensing Central Perturbations by Planets in Binary Stellar Systems under the Strong Finite-Source Effect
Sun-Ju Chung,Byeong-Gon Park
Physics , 2010, DOI: 10.1088/0004-637X/713/2/865
Abstract: We investigate high-magnification events caused by planets in wide binary stellar systems under the strong finite-source effect, where the planet orbits one of the companions. From this, we find that the pattern of central perturbations in triple lens systems commonly appears as a combination of individual characteristic patterns of planetary and binary lens systems in a certain range where the sizes of the caustics induced by a planet and a binary companion are comparable, and the range changes with the mass ratio of the planet to the planet-hosting star. Specially, we find that because of this central perturbation pattern, the characteristic feature of high-magnification events caused by the triple lens systems appears in the residual from the single-lensing light curve despite the strong finite-source effect, and it is discriminated from those of the planetary and binary lensing events and thus can be used for the identification of the existence of both planet and binary companion. This characteristic feature is a simultaneous appearance of two features. First, double negative-spike and single positive-spike features caused by the binary companion appear together in the residual, where the double negative spike occurs at both moments when the source enters and exits the caustic center and the single positive spike occurs at the moment just before the source enters into or just after the source exits from the caustic center. Second, the magnification excess before or after the single positive-spike feature is positive due to the planet, and the positive excess has a remarkable increasing or decreasing pattern depending on the source trajectory.
Distinguishing central perturbations by binary stellar and planetary systems under the moderately strong finite-source effect
Sun-Ju Chung,Chung-Uk Lee
Physics , 2011, DOI: 10.1088/0004-637X/741/2/118
Abstract: We investigate high-magnification events caused by wide binary stellar and planetary systems under the moderately strong finite-source effect where the diameter of the source star is comparable with the caustics induced by a binary companion and a planet. From this investigation, we find that a characteristic feature in the central perturbations induced by the binary systems commonly appears in a constant range where the size of the caustic induced by the binary companion is between 1.5 and 1.9 times of the diameter of the source, whereas in the central perturbations induced by the planetary systems the feature commonly appears in a range where the ratio of the size of the caustic induced by the planet to the source diameter changes with the planet/primary mass ratio. High-magnification events caused by the binary and planetary systems with the characteristic feature produce a distinctive short-duration bump in the residuals from the single-lensing light curve, where the bump occurs near the time of peak magnification of the events. Because of a well-known planet/binary degeneracy, we compare binary- and planetary-lensing events with the short-duration bump in the residuals. As a result, we find the features of the binary-lensing events that are discriminated from the planetary-lensing events despite the moderately strong finite-source effect and thus can be used to immediately distinguish between the binary and planetary companions. We also find the feature that appears only in binary-lensing events with a very low mass ratio or planetary-lensing events. This implies that the lens systems with the feature have a very low mass binary companion (such as a brown dwarf) or a planet.
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