• Archives of Pharmacal Research
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• v.24 no.4
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• pp.292-296
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• 2001

Three prolyl endopeptidase (PEP) inhibitors were isolated from the methanolic extract of green tea leaves. They were identified as (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (+)-gallucatechin gallate with the $IC_{50}$ values of 1.42${\times}$$10^{-4}$mM, $1.02{\times}10^{-2}$mM, and $1.09{\times}10^{-4}$mM, respectively. They were non-competitive with a substrate in Dixon plots and did not show any significant effects against other serine proteases such as elastase, trypsin, and chymotrypsin, suggesting that they were relatively specific inhibitors against PER The isolated compounds are expected to be useful for preventing and curing of Alzheimer's disease.

• Natural Product Sciences
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• v.25 no.2
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• pp.150-156
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• 2019

Conventional extraction of oil and azadirachtin, a botanical insecticide, from Azadirachta indica involves defatting the seeds and leaves using hexane followed by azadirachtin extraction with a polar solvent. In order to simplify the process while maintaining the yield we explored a binary extraction approach using Soxhlet extraction device and hexane and ethanol as non-polar and polar solvents at various ratios and extraction times. The highest oil and azadirachtin yields were obtained at 6 h extraction time using a 50:50 solvent mixture for both neem leaves (44.7 wt%, $720mg_{Aza}/kg_{leaves}$) and seeds (53.5 wt%, $1045mg_{Aza}/kg_{leaves}$), respectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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• pp.475-491
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• 2012

Green Chemistry emerged at the end of 20th century, which aims the development of the technologies for the sustainable society at the molecular level. Most products we consume in everyday life are produced through chemical processes, and we often oversee the fact that huge amount of solvents are used and disposed. At the present time most solvents used in laboratories as well as industries are volatile organic compounds(VOC), which gives health and environmental problems. Therefore scientists are seeking new materials which have equivalent properties of VOCs as solvent, and at the same time gives no health and environmental problems. In this brief review, the author describes the present status of research and development activities of green solvent materials throughout research societies worldwide. At present the most attractive green solvent candidates are water, glycerol, supercritical carbon dioxide and ionic liquids. In order to give the pictures of these materials, the author tried to introduce the overall aspects of green solvents in various chemical reaction as well as catalytic roles.

• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.143-148
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• 2005

This review aims to show that industrial sustainable chemistry, minimizing or reducing the ecological impacts by the chemicals, is not an emerging trend, but is already a reality through the application of 'White Biotechnology' such as 'green' chemistry and engineering expertise. A large number of current industrial case studies are presented, as well as new developments from the chemical industry. The case studies cover new chemistry, new process design and new equipment. By articulating the requirements for industrial application of sustainable chemistry, this review also seeks to bridge any existing gap between academia and industry regarding the R & D and engineering challenges needed to ensure green chemistry research enables a more sustainable future chemical industry considering eco-toxicological impacts.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.255-260
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• 2012

A new series of silaanthracenophanes 2-5 composed of 1,8-diethynylanthracene unit has been synthesized from silylation reactions of 1,8-di(lithioethynyl)anthracene with 1,3-dichloro-1,1,3,3-tetraalkyldisiloxanes and 1,2-dichlorotetramethyldisilane. The silaanthracenophane products 2-4 were characterized by spectroscopic methods and X-ray crystallographic analysis.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2523-2528
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• 2012

Green phosphors $(Zn_{1-a-b}M_aM^{\prime}_b)_xGa_yS_{x+3y/2}:Eu^{2+}$ (M, M' = alkali earth ions) with x = 2 and y = 2-5 were prepared, starting from ZnO, MgO, $SrCO_3$, $Ga_2O_3$, $Eu_2O_3$, and S with a flux $NH_4F$ using a conventional solidstate reaction. A phosphor with the composition of $(Zn_{0.6}Sr_{0.3}Mg_{0.1})_2Ga_2S_5:Eu^{2+}$ produced the strongest luminescence at a 460-nm excitation. The observed XRD patterns indicated that the optimized phosphor consisted of two components: zinc thiogallate and zinc sulfide. The characteristic green luminescence of the $ZnS:Eu^{2+}$ component on excitation at 460 nm was attributed to the donor-acceptor ($D_{ZnGa_2S_4}-A_{ZnS}$) recombination in the hybrid boundary. The optimized green phosphor converted 17.9% of the absorbed blue light into luminescence. For the fabrication of light-emitting diode (LED), the optimized phosphor was coated with MgO using magnesium nitrate to overcome their weakness against moisture. The MgO-coated green phosphor was fabricated with a blue GaN LED, and the chromaticity index of the phosphor-cast LED (pc-LED) was investigated as a function of the wt % of the optimized phosphor. White LEDs were fabricated by pasting the optimized green (G) and the red (R) phosphors, and the commercial yellow (Y) phosphor on the blue chips. The three-band pc-WLED resulted in improved color rendering index (CRI) and corrected color temperature (CCT), compared with those of the two-band pc-WLED.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.255-257
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• 2014

This study was conducted to determine the attractive effects of Plutella xylostella adults to light emitting diode (LED) trap in greenhouse and compared with those of no light trap and black-light which is typically used in commercial luring lamp. The green LED trap captured more P. xylostella when compared with black-light trap, whereas the no light trap was a little attractive to P. xylostella adults. These results indicated that the green LED traps could be used for environmental insect pest control.

• Journal of Applied Biological Chemistry
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• v.59 no.3
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• pp.203-206
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• 2016

This study was conducted to evaluate the attraction effects of Sitotroga cerealella and Plodia interpunctella adults to light emitting diode (LED) trap in granary and compared with the results of the black light bulb (BLB) trap, which is typically used as a commercial trap. The blue LED was more attractive to S. cerealella than the BLB. The green LED was significantly more attractive to P. interpunctella than the BLB. Furthermore, the external installation of blue LED and green LED was about 1.7 times more attractive to S. cerealella and P. interpunctella, respectively, than the internal installation. These results indicated that blue LED and green LED traps can be used for eco-friendly insect pest control in granary.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.2051-2053
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• 2005

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2029-2035
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• 2013

The impact of phosphorous (P)-doping on the electrochemical performance and surface chemistry of soft carbon is investigated by means of galvanostatic cycling and ex situ X-ray photoelectron spectroscopy (XPS). P-doping plays an important role in storing more Li ions and discernibly improves reversible capacity. However, the discharge capacity retention of P-doped soft carbon electrodes deteriorated at $60^{\circ}C$ compared to non-doped soft carbon. This poor capacity retention could be improved by vinylene carbonate (VC) participating in forming a protective interfacial chemistry on soft carbon. In addition, the effect of P-doping on exothermic thermal reactions of lithiated soft carbon with electrolyte solution is discussed on the basis of differential scanning calorimetry (DSC) results.