• Title/Summary/Keyword: Crown compounds

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Synthesis of Diazacrown Ethers Containing Phenolic Side Arms and Their Complex with Divalent Metal Ions

  • Chi, Ki-Whan;Ahn, Yoon-Soo;Shim, Kwang-Taeg;Huh, Hwang;Ahn, Jeong-Soo
    • Bulletin of the Korean Chemical Society
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    • v.23 no.5
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    • pp.688-692
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    • 2002
  • The aminomethylation of phenols with para-substituents by the Mannich reaction has successfully been accomplished to produce the Mannich bases 2-6. The compounds 7-8 have also been synthesized in order to identify the effect of the side arms and t he macrocycle in the complex formation. Protonation constants and stability constants of the double armed diaza-18-crown-6 ethers 2-7 with metal ions have been determined by potentiometric method at 25 $^{\circ}C$ in 95 % methanol solution. Under a basic condition (pH > 8.0), the double-armed crown ethers 2-6 revealed stronger interaction with divalent metal ions than the simple diazacrown ether 1. The stability constants with these metal ions were Co 2+ < Ni2+ < Cu2+ > Zn 2+ in increasing order, which are in accordance with the order of the Williams-Irving series. The stability constants with alkali earth metal ions were Ca 2+ < Sr 2+ < Ba 2+ in increasing order, which may be explained by the concept of size effect. It is noteworthy that the hosts 2-6, which have phenolic side arms and a macrocycle, bind stronger with metal ions than the hosts 1 and 7. On the other hand, the host 8, which has phenolic side arms with a pyperazine ring,provided comparable stability constants to those with the host 3. These facts demonstrate that phenolic side arms play a more important role than the azacrown ether ring in the process of making a complex with metal ions especially in a basic condition. In particular, the log KML values for complexation of divalent metal ions with the hosts 2-6 had the sequence, i.e., 2 (R=OCH3) < 3 (R=CH3) < 4 (R=H) < 5 (R=Cl) < 6 (R=CF3). The stability constants of the hosts 5 and 6 containing an electron-withdrawing group are larger than those of the hosts 2 and 3 containing an electron-donating group. This substituent effect is attributed to the solvent effect in which the aryl oxide with an electron-donating group has a tendency to be tied strongly with protic solvents.

Application of Solid Phase Microextraction to the Analysis of Pesticides in Vegetables

  • Cho Tae-Hee;Kang Hee-Gon;Kim Tae-Rang;Chang Min-Su
    • Proceedings of the Korean Society of Food Hygiene and Safety Conference
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    • 2001.10a
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    • pp.171-174
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    • 2001
  • Solid phase micro-extraction (SPME), a solvent-free, rapid and inexpensive method for the extraction of organic compounds from aqueous sample matrices, was evaluated for determination of the 120 pesticides in vegetables such as crown daisy, perilla leaf, leafy lettuce and to mato. The analysis conditions were chosen for the SPME method: 15 min of immersion of the PDMS fiber in 10 ml of the solution with stirring at 1,000 rpm. The recovery tests were carried out in triplicate. The range of recoveries was 0-142% for organochlorine pesticides and $4.9\sim200\%$ for organophosphorus pesticides. The recoveries were very low in the pesticide groups with low solubility in water. The recoveries became lower in proportion to the interference materials in vegetables. The recovery in tomato was relatively higher than that in perilla Ie af and crown daisy. The recovery values obtained by SPE and SPME were compared. In leaf y lettuce, recovery obtained by SPE method ranged from $58.1\%\;to\;136.1\%$ and recovery by SPME ranged from $9.6\%\;to\;176.3\%$ In organophosphorus pesticides. The recovery in SPME method was satisfactory with $136\%$ for ethoprophos, $119\%$ for methidathion and $113\%$ for diazinon. Meanwhile, recovery of EPN, phenthoate and 2,4-DDT revealed relatively low value of $38\%,\;41\%\;and\;3.4\%,$ respectively. However, most of pesticides applied to SPME method sho wed constant recovery and precision. From these results, it can be concluded that solid phase micro-extraction might be an appropriate method for the screening test of pesticides in vegetables.

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A Study on the Original State of the Buildings in NakSunJae Area (낙선제(樂善齊) 일곽(一廓) 건축(建築)의 조영(造營)에 관한 복원적(復元的) 고찰(考察))

  • Noh, Jin-Ha;Lee, Sang-Hae
    • Journal of architectural history
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    • v.4 no.1
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    • pp.43-70
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    • 1995
  • This paper aims to clarify the historical background and the architectural purpose of the buildings in NakSunJae area to the original state. Through the investigation, the clarified facts are as follows. 1. The relation with the buildings for the Crown Prince in the ChangDok Palace By constructing buildings in the NakSunJae area, the spatial conception of the Royal Palace was changed, that is, buildings for the Crown Prince in the ChangDok Palace disappeared and they became to belong to the ChangGyeong Palace. Moreover, by constructing the NakSunJae and its attached buildings, the area for the Crown Prince shifted to use as a private area for the king. 2. The date and the purpose of the construction The NakSunJae area is consisted of three compounds of building: NakSunJae, SukBokHun and SooKangJae. The NakSunJae was constructed for the king HunChong's private occupancy in 1847 and the SukBokHun for a residence of a royal concubine Kim, in 1847. The SooKangJae was originally built in 1785 in the SooKang Palace where the ex-king took up as his residence after abdicate the throne. Later on, it was repaired as the residence of the Queen SoonWon, king HunChong's grandmother, in commemoration for the 60th anniversary of her birth in 1848. 3. Architectural features of the NakSunJae area at the time of construction First, as the NakSunJae area is surrounded by quite high hills in northeast and by low hills in southwest, it is naturally distinguished from its surroundings and gives a cosy feeling. Second, the NakSunJae area shows very untrammeled style of arrangement in general, because it was constructed as a private occupancy for the king. other buildings are arranged in the latticing orderly, nonetheless, they are free by themselves from a strict form and make themselves an area full of variety. Third, the buildings in the NakSunJae area have a characteristic of naivety of common people's houses, because they were not an official but private place for the king, his concubine and his grandmother. Forth, the ornaments in the NakSunJae area are variously, elegantly and harmoniously patterned with the meaning of good luck. Fifth, back garden in the NakSunJae area was made by taking advantage of sloping hills. The back garden is beautifully configurated by arranging various constituent elements of pavilions, tiered flower beds, chimneys, decorated walls, small doors between walls, stoneworks and trees.

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Application of an Interferometric Biosensor Chip to Biomonitoring an Endocrine Disruptor

  • Kim, Byung-Woo;Lim, Sung-Hyuk
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.2
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    • pp.118-126
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    • 2004
  • Recombinant E.coli ACV 1003 (recA::lacZ) releasing ${\beta}$-galactosidase by a SOS regulon system, when exposed to DNA-damaging compounds, have been used to effectively monitor endocrine disruptors. Low enzyme activity of less than 10 units/mL, corresponding to a $\mu\textrm{g}$/L(ppb) range of an endocrine disruptor (tributyl tin, bisphenol A. etc.), can be rapidly determined, not by a conventional time-consuming and tedious enzyme assay, but by an alternative interferometric biosensor. Heavily boron-doped porous silicon for application as an interferometer, was fabricated by etching to form a Fabry-Perot fringe pattern, which caused a change in the refractive index of the medium including ${\beta}$-galactosidase. In order to enhance the immobilization of the porous silicon surface, a calyx crown derivative (ProLinker A) was applied, instead of a conventional biomolecular affinity method using biotin. This resulted in a denser linked formation. The change in the effective optical thickness versus ${\beta}$-galactosidase activity, showed a linear increase up to a concentration of 150 unit ${\beta}$-galactosidase/mL, unlike the sigmoidal increase pattern observed with the biotin.

The ethnomedicinal, phytochemical and pharmacological properties of Phaleria macrocarpa (Scheff). Boerl.

  • Othman, Siti Nur Atiqah Md;Sarker, Satyajit Dey;Nahar, Lutfun;Basar, Norazah
    • CELLMED
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    • v.4 no.4
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    • pp.22.1-22.12
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    • 2014
  • Phaleria macrocarpa (Scheff.) Boerl. is a dense evergreen tree of the family Thymelaeceae. This plant is popular with the name of Mahkota dewa, which is literally translated as God's Crown. All parts of this plant including fruits, seeds, stem, and leaves have well known therapeutic properties and have been extensively used in traditional medicine for the treatment of various diseases such as cancer, diabetes mellitus, allergies, kidney disorders, blood diseases, stroke, and acne with satisfactory results. Scientific findings on bioactivities of P. macrocarpa also demonstrated different pharmacological properties of various parts of this plant including cytotoxic, antidiabetic, antioxidant, anti-inflammatory, antibacterial, and antihypertensive activities. Phytochemicals studies of P. macrocarpa revealed the presence of several classes of compounds such as benzophenones, terpenoids, xanthones, lignans, acids, and sugars. This review aims to provide a critical overview on botanical description, traditional usage, phytochemicals, and pharmacological activities of P. macrocarpa.

Surface Order of Hexagonal Columnar Mesophases Induced by Molecular Assembly

  • Kim, Sang-Ouk;Ko, Young-Koan;Yoon, Dong-Ki;Kang, Sang-Yoon;Jung, Hee-Tae
    • KIEE International Transactions on Electrophysics and Applications
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    • v.11C no.2
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    • pp.32-36
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    • 2001
  • We investigate the surface order, defects and morphology of hexagonal columnar mesophases, Having a crown ether at one end which forms the center of the column and three fluorinated tails at the other, The orientation of the columns was successfully controlled by surface anchoring: Columns were aligned perpendicularly to an evaporated carbon surface, and the planar alignment do asymmetric compounds was induced by a water surface. TEM images show that there is a high degree of perfection in the packing do the cylinders. The hexagonal columnar mesophase (F(sub)h) was confirmed by direct images and the corresponding electron diffractions, where ordered cylindrical moieties are packed on a hexagonal lattice. The column of 12F8-ABG-15C5 was much straighter, compared with that of 12F8-AG-B15C5, resulting from the degrees of regular stacking. Elementary edge dislocation, grain boundary and +1/2 disclination have been observed, although the defects are generally rare.

Development of Organic Paste Porcelain for Fixed Prostheses (유기조성물을 이용한 페이스트형 일반도재 시스템)

  • Han, Jung-Suk;Lee, Myung-Hyun;Kim, Dae-Hyun;Chung, Hun-Young
    • Journal of Dental Rehabilitation and Applied Science
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    • v.20 no.2
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    • pp.109-120
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    • 2004
  • INTRODUCTION: The build-up method has been used for application of porcelain powder on the metal framework to make final tooth shape conventionally. This method takes time and need skill to mimic final shade and shape of porcelain fused to metal crown. The purpose of this study was to develop standard shape and shade laminating porcelain forms to reduce build-up time. METHODS: To make tooth form porcelain paste, several liquid organic compounds were added to conventional feldspathic porcelain. The amount of additives and rheologic property were tested to find out best composition. Comparison of mixing methods to reduced porosity, proper heating schedule, and measurement of shrinkage amount and residual organic materials were performed to set-up standard procedures. Finally, biaxial flexural strength and color of preformed laminated paste porcelain were compared with those of porcelain which fabricated by the conventional build-up method. RESULTS: There was no significant difference in physical properties and color stability between two fabrication methods after various testing methods. Conclusion: This new build-up method can be applied to fabricate the PFM crown and bridge without any loss of strength and optical properties.

The Influence of UV Irradiation on Stilbene Contents and Gray Mold Incidence in Grapevine Leaves (자외선 조사가 포도잎의 Stilbene 함량 및 잿빛곰팡이병 발생에 미치는 영향)

  • Choi, Seong-Jin
    • Horticultural Science & Technology
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    • v.30 no.5
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    • pp.493-500
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    • 2012
  • In order to confirm the possibility of UV utilization as a means for disease protection in grapevine the stilbene contents and the disease incidence in UV irradiated leaves were investigated. UV irradiation significantly increased the contents of resveratrol, piceatannol and piceid, in them, resveratrol and piceid showed in vitro inhibition of spore germination and mycelium growth of Botrytis cinerea. The accumulation of both the stilbenes in UV irradiated leaves seems to be enough to inhibit the B. cinerea growth, since the formation of necrotic spot on the leaves was considerably inhibited when they were inoculated with the conidial spores of B. cinerea. However the stilbenes were accumulated only in the leaves exposed directly to UV showing a limited translocation ability of the compounds. Thus it would be necessary to develop a method to evenly irradiate the entire crown of plant with UV in order to expect to protect them from disease by UV irradiation.

Inhibitory effects of Doenjang, Korean traditional fermented soybean paste, on oxidative stress and inflammation in adipose tissue of mice fed a high-fat diet

  • Nam, Ye Rim;Won, Sae Bom;Chung, Young-Shin;Kwak, Chung Shil;Kwon, Young Hye
    • Nutrition Research and Practice
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    • v.9 no.3
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    • pp.235-241
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    • 2015
  • BACKGROUND/OBJECTIVES: Doenjang, Korean traditional fermented soybean paste has been reported to have an anti-obesity effect. Because adipose tissue is considered a major source of inflammatory signals, we investigated the protective effects of Doenjang and steamed soybean on oxidative stress and inflammation in adipose tissue of diet-induced obese mice. MATERIALS/METHODS: Male C57BL/6J mice were fed a low fat diet (LF), a high-fat diet (HF), or a high-fat containing Doenjang diet (DJ) or a high-fat containing steamed soybean diet (SS) for 11 weeks. RESULTS: Mice fed a DJ diet showed significantly lower body and adipose tissue weights than those in the HF group. Although no significant differences in adipocyte size and number were observed among the HF diet-fed groups, consumption of Doenjang alleviated the incidence of crown-like structures in adipose tissue. Consistently, we observed significantly reduced mRNA levels of oxidative stress markers (heme oxygenase-1 and $p40^{phox}$), pro-inflammatory adipokines (tumor necrosis factor alpha and macrophage chemoattractant protein-1), macrophage markers (CD68 and CD11c), and a fibrosis marker (transforming growth factor beta 1) by Doenjang consumption. Gene expression of anti-inflammatory adipokine, adiponectin was significantly induced in the DJ group and the SS group compared to the HF group. The anti-oxidative stress and anti-inflammatory effects observed in mice fed an SS diet were not as effective as those in mice fed a DJ diet, suggesting that the bioactive compounds produced during fermentation and aging may be involved in the observed health-beneficial effects of Doenjang. CONCLUSIONS: Doenjang alleviated oxidative stress and restored the dysregulated expression of adipokine genes caused by excess adiposity. Therefore, Doenjang may ameliorate systemic inflammation and oxidative stress in obesity via inhibition of inflammatory signals of adipose tissue.

Theoretical and quantitative structural relationships of the electrochemical properties of Cis-unsaturated thiocrown ethers and n-type material bulk-heterojunction polymer solar cells as supramolecular complexes [X-UT-Y]@R (R = PCBM, p-EHO-PCBM, and p-EHO-PCBA)

  • Taherpour, Avat Arman;Biuki, Farzaneh
    • Journal of Information Display
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    • v.12 no.3
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    • pp.145-152
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    • 2011
  • Since the discovery of fullerenes as a class of nanostructure compounds, many potential applications have been suggested for their unusual structures and properties. The isolated pentagon rule (IPR) states that all pentagonal carbon rings are isolated in the most stable fullerene. Fullerenes $C_n$ are a class of spherical carbon allotrope group with unique properties. Electron transfer between fullerenes and other molecules is thought to involve the transfer of electrons between the molecules surrounding the fullerene cage. One class of electron transfer molecules is the methanofullerene derivatives ([6,6]-phenyl $C_{61}$-butyric acid methyl ester (PCBM), 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid methyl ester (p-EHO-PCBM), and 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid (p-EHO-PCBA), 10-12). It has been determined that $C_{60}$ does not obey IPR. Supramolecular complexes 1-9 and 10-12 are shown to possess a previously unreported host.guest interaction for electron transfer processes. The unsaturated, cis-geometry, thiocrown ethers, (1-9) (described as [X-UT-Y], where X and Y indicate the numbers of carbon and sulfur atoms, respectively), are a group of crown ethers that display interesting physiochemical properties in the light of their conformational restriction compared with a corresponding saturated system, as well as the sizes of their cavities. Topological indices have been successfully used to construct mathematical methods that relate structural data to various chemical and physical properties. To establish a good relationship between the structures of 1-9 with 10-12, a new index is introduced, ${\mu}_{cs}$. This index is the ratio of the sum of the number of carbon atoms ($n_c$) and the number of sulfur atoms ($n_s$) to the product of these two numbers for 1-9. In this study, the relationships between this index and oxidation potential ($^{ox}E_1$) of 1-9, as well as the first to third free energies of electron transfer (${\Delta}G_{et(n)}$, for n = 1-3, which is given by the Rehm-Weller equation) between 1-9 and PCBM, p-EHO-PCBM, and p-EHO-PCBA (10-12) as [X-UT-Y]@R(where R is the adduct PCBM, p-EHO-PCBM, and p-EHO-PCBA group) (13-15) supramolecular complexes are presented and investigated.