• Title/Summary/Keyword: carbazole

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Conditioning of the Extraction of Acidic Polysaccharide from Red Ginseng Marc (홍삼박으로부터 산성다당체의 최적 추출 조건 분석)

  • Chang, Eun-Ju;Park, Tae-Kyu;Han, Yong-Nam;Hwang, Keum-Hee
    • Korean Journal of Pharmacognosy
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    • v.38 no.1
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    • pp.56-61
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    • 2007
  • This study was carried out to investigate the optimum conditions for extraction of acidic polysaccharides from red ginseng marc produced by manufacturing alcoholic extract from red ginseng. Method of carbazole-sulfuric acid was applied to determine the amount of acidic polysaccharides in red ginseng marc. The amounts of acidic polysaccharides in water extract of red ginseng marc were increased with increasing extraction temperature. The contents of acidic polysaccharides were not significantly different despite of the extraction time increasing from 6 hours to 48 hours. The contents of starch in water-extract of red ginseng marc were increased with increasing extraction temperature. The starch amounts in water extract of red ginseng marc extracted for 48 hours were increased. The yields of polysaccharide precipitated from water-extract of red ginseng marc were increased with increasing extraction temperature. The hydration rate of acidic polysaccharides and starch from water-extract of red ginseng marc were decreased with increasing extraction temperature. The contents of starch were not significantly different despite of the extraction time increasing from 6 hours to 48 hours at $8^{\circ}C$. However, the rehydration rate of acidic polysaccharide for 48 hours were decreased at $8^{\circ}C$. The rehydration rate of acidic polysaccharide and starch extracted from 6 hours to 24 hours at $25^{\circ}C$ were not significantly different, but those extracted for 48 hours were increased. From the above results, we suggest that by altering the extraction conditions in red ginseng marc it is possible to develop optimum conditions for extraction that modulate the proportions of acidic polysaccharide and starch.

Thickness Effect of ZnO Electron Transport Layers in Inverted Organic Solar Cells

  • Jang, Woong-Joo;Cho, Hyung-Koun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.377-377
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    • 2011
  • Organic solar cells (OSCs) with low cost have been studied to apply on flexible substrate by solution process in low temperature [1]. In previous researches, conventional organic solar cell was composed of metal oxide anode, buffer layer such as PEDOT:PSS, photoactive layer, and metal cathode with low work function. In this structure, indium tin oxide (ITO) and Al was generally used as metal oxide anode and metal cathode, respectively. However, they showed poor reliability, because PEDOT:PSS was sensitive to moisture and air, and the low work function metal cathode was easily oxidized to air, resulting in decreased efficiency in half per day [2]. Inverted organic solar cells (IOSCs) using high work function metal and buffer layer replacing the PEDOT:PSS have focused as a solution in conventional organic solar cell. On the contrary to conventional OSCs, ZnO and TiO2 are required to be used as a buffer layer, since the ITO in IOSC is used as cathode to collect electrons and block holes. The ZnO is expected to be excellent electron transport layer (ETL), because the ZnO has the advantages of high electron mobility, stability in air, easy fabrication at room temperature, and UV absorption. In this study, the IOSCs based on poly [N-900-hepta-decanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)] (PCDTBT) : [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) were fabricated with the ZnO electron-transport layer and MoO3 hole-transport layer. Thickness of the ZnO for electron-transport layer was controlled by rotation speed in spin-coating. The PCDTBT and PC70BM were mixed with a ratio of 1:2 as an active layer. As a result, the highest efficiency of 2.53% was achieved.

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A Study on Pectic Substances of Korean Apple Varieties (한국산 사과의 품종별 펙틴물질들에 관한 연구)

  • 임화재;이혜수
    • Korean journal of food and cookery science
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    • v.2 no.1
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    • pp.65-70
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    • 1986
  • Total pectin content of Korean apple varieties at optimum harvest time was deter-mined by carbazole reaction method and pectin fraction content in each variety was also determined. Properties of pectin extracted ty 2a Sodium hexa metaphesphate were compared with commercial pectin. Among apple varieties, pectin contents varied in the range of 0.26-0.48% on fresh basis and 1.76-4. 0% on dry basis. Ball's was the highest and then high in order of Spur early blaze, Golden delicious, Fuji. , Jonathan. In each pectin fraction, soluble pectin fractions in Rall's was the lowest and in both Spur early blaze and Golden Delicious were highest but insoluble fractions in the latter were lowest. Thub the changes in poetic substances in Spur early blaze and Golden delicious seem to he occurred: during early ripening. In the analysis of properties of isolated pectin, ash, anhydrogalacturonic arid7(AUA) content and methoxyl content were different among apple varieties. Ash and methoxyl content in all isolated pectin were higher and AUA content lower than in commercial pectin. Degree of esterification (DE) in all apple varieties were above 70%.

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Pyrrolo[3,2-b]pyrrole-Based Copolymers as Donor Materials for Organic Photovoltaics

  • Song, Suhee;Ko, Seo-Jin;Shin, Hyunmin;Jin, Youngeup;Kim, Il;Kim, Jin Young;Suh, Hongsuk
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3399-3404
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    • 2013
  • A new accepter unit, pyrrolo[3,2-b]pyrrole-2,5-dione, was prepared and utilized for the synthesis of the conjugated polymers containing electron donor-acceptor pair for OPVs. Pyrrolo[3,2-b]pyrrole-2,5-dione unit, regioisomer of the known pyrrolo[3,4-c]pyrrole-1,4-dione, is originated from the structure of stable synthetic pigment. The new conjugated polymers with 1,4-diphenylpyrrolo[3,2-b]pyrrole-2,5-dione, thiophene and carbazole were synthesized using Suzuki polymerization to generate P1 and P2. The solid films of P1 and P2 show absorption bands with maximum peaks at about 377, 554 and 374, 542 nm and the absorption onsets at 670 and 674 nm, corresponding to band gaps of 1.85 and 1.84 eV, respectively. To improve the hole mobility of the polymer with 1,4-bis(4-butylphenyl)-pyrrolo[3,2-b]-pyrrole-2,5-dione unit, which was previously reported by us, the butyl group at the 4-positions of the N-substituted phenyl group was substituted with hydrogen and methyl group. The field-effect hole mobility of P2 is $9.6{\times}10^{-5}cm^2/Vs$. The device with $P2:PC_{71}BM$ (1:2) showed $V_{OC}$ value of 0.84 V, $J_{SC}$ value of 5.10 $mA/cm^2$, and FF of 0.33, giving PCE of 1.42%.

Murrayafoline A Induces a G0/G1-Phase Arrest in Platelet-Derived Growth Factor-Stimulated Vascular Smooth Muscle Cells

  • Han, Joo-Hui;Kim, Yohan;Jung, Sang-Hyuk;Lee, Jung-Jin;Park, Hyun-Soo;Song, Gyu-Yong;Nguyen, Manh Cuong;Kim, Young Ho;Myung, Chang-Seon
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.5
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    • pp.421-426
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    • 2015
  • The increased potential for vascular smooth muscle cell (VSMC) growth is a key abnormality in the development of atherosclerosis and post-angioplasty restenosis. Abnormally high activity of platelet-derived growth factor (PDGF) is believed to play a central role in the etiology of these pathophysiological situations. Here, we investigated the anti-proliferative effects and possible mechanism(s) of murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa Guillamin (Rutaceae), on PDGF-BB-stimulated VSMCs. Murrayafoline A inhibited the PDGF-BB-stimulated proliferation of VSMCs in a concentration-dependent manner, as measured using a non-radioactive colorimetric WST-1 assay and direct cell counting. Furthermore, murrayafoline A suppressed the PDGF-BB-stimulated progression through $G_0/G_1$ to S phase of the cell cycle, as measured by [$^3H$]-thymidine incorporation assay and cell cycle progression analysis. This anti-proliferative action of murrayafoline A, arresting cell cycle progression at $G_0/G_1$ phase in PDGF-BB-stimulated VSMCs, was mediated via down-regulation of the expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, and proliferating cell nuclear antigen (PCNA), and the phosphorylation of retinoblastoma protein (pRb). These results indicate that murrayafoline A may be useful in preventing the progression of vascular complications such as restenosis after percutaneous transluminal coronary angioplasty and atherosclerosis.

A Study on the Synthesis of Dipyrrolylbenzenes (Dipyrrolylbenzene들의 합성에 관한 연구)

  • 정대일;변석인;송현애;이도훈;김윤영;이용균;박유미;최순규;한정태
    • Journal of Life Science
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    • v.13 no.6
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    • pp.836-842
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    • 2003
  • 1-(2-Aminophenyl)pyrrole 5 was synthesized by using 1,2-phenylenediamine with 2,5-dimethoxy-tetrahydrofuran in glacial acetic acid. 1-(3-Aminophenyl)pyrrole 7 and 1,3-dipyrrolylbenzene 8 were obtained by using 1,3-phenylene-diamine with 2,5-dimethoxytetrahydrofuran in glacial acetic acid. 1,4-Dipyrrolylbenzene 10 was synthesized by using 1,4-phenylenediamine with 2,5-dimethoxy-tetrahydrofuran in glacial acetic acid. Aminophenylpyrroles 5, 7 and dipyrrolylbenzenes 8, 10 were respectively synthesized by treatment of 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylene-diamine and 2,5-dimethoxytetrahydrofuran in (1) no solvent or (2) acrylic acid or (3) silica gel or (4) acrylic acid and silica gel or (5) silica gel and glacial acetic acid instead of glacial acetic acid. The best yield for dipyrrolylbenzene 10 was obtained when silica gel and glacial acetic acid was used. 9-Phenyl-carbazole 11 was synthesized by treatment of 1-phenylpyrrole with 2,5-dimethoxy-tetrahydrofuran in glacial acetic acid.

An Aminopropyl Carbazole Derivative Induces Neurogenesis by Increasing Final Cell Division in Neural Stem Cells

  • Shin, Jae-Yeon;Kong, Sun-Young;Yoon, Hye Jin;Ann, Jihyae;Lee, Jeewoo;Kim, Hyun-Jung
    • Biomolecules & Therapeutics
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    • v.23 no.4
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    • pp.313-319
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    • 2015
  • P7C3 and its derivatives, 1-(3,6-dibromo-9H-carbazol-9-yl)-3-(p-tolylamino)propan-2-ol (1) and N-(3-(3,6-dibromo-9H-carbazol-9-yl)-2-hydroxypropyl)-N-(3-methoxyphenyl)-4-methylbenzenesulfonamide (2), were previously reported to increase neurogenesis in rat neural stem cells (NSCs). Although P7C3 is known to increase neurogenesis by protecting newborn neurons, it is not known whether its derivatives also have protective effects to increase neurogenesis. In the current study, we examined how 1 induces neurogenesis. The treatment of 1 in NSCs increased numbers of cells in the absence of epidermal growth factor (EGF) and fibroblast growth factor 2 (FGF2), while not affecting those in the presence of growth factors. Compound 1 did not induce astrocytogenesis during NSC differentiation. 5-Bromo-2'-deoxyuridine (BrdU) pulsing experiments showed that 1 significantly enhanced BrdU-positive neurons. Taken together, our data suggest that 1 promotes neurogenesis by the induction of final cell division during NSC differentiation.

Comparison of Phytochemical Constituents According to the Cultivation Method (Paddy Field Cultivation, Upland Field Cultivation) of Korean Fresh Ginseng (한국산 수삼의 재배환경(논, 밭)에 따른 식물화학성분 비교)

  • Her, Jae Young;Kim, Do Hyeong;Hwang, Yu Jin;Ko, Sung Kwon;Yang, Byung Wook
    • Journal of Korean Medicine for Obesity Research
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    • v.22 no.1
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    • pp.21-29
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    • 2022
  • Objectives: This study aimed to examine the changes in ingredients according to its cultivation method by examining the content of saponin and non-saponin components of ginseng. Methods: Ginseng saponin component analysis was compared and reviewed using the high-performance liquid chromatography method, and acidic polysaccharide component was measured using the carbazole sulfuric acid method. Results: The comparative analysis of ginseng saponin content of 4 and 6 years old fresh ginseng showed the following results. According to the cultivation method, upland field cultivation fresh ginseng showed higher average content of crude saponin than paddy field cultivation fresh ginseng. Whereas, paddy field cultivation fresh ginseng showed higher average content of total saponin than upland field cultivation fresh ginseng. Ginsenoside Rb1 showed higher content of paddy field cultivation fresh ginseng than upland field cultivation fresh ginseng in 6 years old ginseng. However, it showed higher content of upland field cultivation fresh ginseng than paddy field cultivation fresh ginseng in 4 years old ginseng. Additionally, ginsenoside Rg1 showed higher content of paddy field cultivation fresh ginseng than upland field cultivation fresh ginseng in 6 years old ginseng, whereas upland field cultivation fresh ginseng showed higher content of paddy field cultivation fresh ginseng in 4 years old ginseng. The effect on the content of ginseng saponins and acidic polysaccharides according to paddy field and upland field cultivation methods is considered to be small. Conclusions: The paddy field cultivation method, which is more efficient in production cost due to depletion of farmland and long-distance cultivation, is considered to be an economical cultivation method.

Studies on Degradation of Nucleic acid and Related Compounds by Microbial Enzymes (미생물 효소에 의한 핵산 및 그의 관련물질의 분해에 관한 연구)

  • Kim, Sang-Soon
    • Applied Biological Chemistry
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    • v.13 no.2
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    • pp.111-129
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    • 1970
  • As a series of studies on the nucleic acids and their related substances 210 samples were collected from 76 places such as farm soil, compost of heap, nuruk and meju to obtain microbial strains which produce 5'-phosphodiesterase. From these samples total of 758 strains were isolated by the use of dilution pour plate method. For all isolated strains primary screening of the productivity of RNA depolymerase was performed and useful strains with regard to 5'-phosphodiesterase productivities were identified. For these useful strains optimum condition, the effect of various compounds on the activity of 5'-phosphodiesterase, and the optimum condition for enzyme reaction were discussed. The quantitative of 5'-mononucleotides produced by the action of 5'-phosphodiesterase was performed using anion-exchange column chromatography and their identified was done by paper chromatography, thinlayer chromatography, ultra violet spectrophotometry, and characteristic color reaction using carbazole and schiff's reagent. (1) Penicillium citreo-viride PO 2-11 and Streptomyces aureus SOA 4-21 from soil were identified as a potent 5'-phosphodiesterase producing strains. (2) Optimum culture conditions for Penicillium citreo-viride PO 2-11 strain isolated were found to be pH 5.0 and $30^{\circ}C$, and the optimum conditions for enzyme action of 5'-phosphodiesterase were pH 4.2 and $60^{\circ}C$. Best carbon source for the production of 5'-phosphodiesterase was found to be sucrose and ammonium nitrate for nitrogen source. Addition of 0.01% corn steep liquor or yeast extract exhibited 20% increase in the amount of 5'-phosphodiesterase production compared to the control. 5'-phosphodiesterase produced by this strain was activated by $Mg^{++},\;Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by EDTA, citrate, $Cu^{++},\;CO^{++}$. 5'-phosphodiesterase produced 5'-mononucleotide from RNA at a rate of 65.81%, and among the 5'-mononucleotides accumulated 5'-GMP only was found to have flavorous and the strain was also found lack of 5'-AMP deaminase. Productivity of flavorous 5'-GMP was found to be 186.7mg per gram of RNA. (3) Optimum culture canditions for the isolated Streptomyces aureus SOA 4-21 strain were pH 7.0 and $28^{\circ}C$, and the optimum conditions for the action of 5'-phosphodiesterase were pH 7.3 and $50^{\circ}C$. The best carbon source for 5'-phosphodiesterase production was found to be glucose and that of nitrogen was asparagine. Addition of 0.01% yeast extract exhibited increased productivity of 5'-phosphodiesterase by 40% compared to the non-added control. 5'-phosphodiesterase produced by this strain was activated by $Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by citrate, EDTA, $Cu^{++}$. It was also found that the strain produce 5'-AMP deaminase in addition to 5'-phosphodiesterase. For this reason although decomposition rate was 63.58% the accumulation of 5'-AMP, 5'-CMP, 5'-GMP and 5'-UMP occurred by the breakdown of RNA. In the course of these reaction 5'-AMP deaminase converted 60% of 5'-AMP thus produced into 5'-IMP and flavorous 5'-mono nucleotide production was significantly increased by this strain over the above mentioned one. Production rates were found to be 171.8mg per grain of RNA for 5'-IMP and 148.2mg per gram of RNA for 5'-GMP, respectively.

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Eco-Friendly Light Emitting Diodes Based on Graphene Quantum Dots and III-V Colloidal Quantum Dots

  • Lee, Chang-Lyoul
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.65-65
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    • 2015
  • In this talk, I will introduce two topics. The first topic is the polymer light emitting diodes (PLEDs) using graphene oxide quantum dots as emissive center. More specifically, the energy transfer mechanism as well as the origin of white electroluminescence in the PLED were investigated. The second topic is the facile synthesis of eco-friendly III-V colloidal quantum dots and their application to light emitting diodes. Polymer (organic) light emitting diodes (PLEDs) using quantum dots (QDs) as emissive materials have received much attention as promising components for next-generation displays. Despite their outstanding properties, toxic and hazardous nature of QDs is a serious impediment to their use in future eco-friendly opto-electronic device applications. Owing to the desires to develop new types of nanomaterial without health and environmental effects but with strong opto-electrical properties similar to QDs, graphene quantum dots (GQDs) have attracted great interest as promising luminophores. However, the origin of electroluminescence (EL) from GQDs incorporated PLEDs is unclear. Herein, we synthesized graphene oxide quantum dots (GOQDs) using a modified hydrothermal deoxidization method and characterized the PLED performance using GOQDs blended poly(N-vinyl carbazole) (PVK) as emissive layer. Simple device structure was used to reveal the origin of EL by excluding the contribution of and contamination from other layers. The energy transfer and interaction between the PVK host and GOQDs guest were investigated using steady-state PL, time-correlated single photon counting (TCSPC) and density functional theory (DFT) calculations. Experiments revealed that white EL emission from the PLED originated from the hybridized GOQD-PVK complex emission with the contributions from the individual GOQDs and PVK emissions. (Sci Rep., 5, 11032, 2015). New III-V colloidal quantum dots (CQDs) were synthesized using the hot-injection method and the QD-light emitting diodes (QLEDs) using these CQDs as emissive layer were demonstrated for the first time. The band gaps of the III-V CQDs were varied by varying the metal fraction and by particle size control. The X-ray absorption fine structure (XAFS) results show that the crystal states of the III-V CQDs consist of multi-phase states; multi-peak photoluminescence (PL) resulted from these multi-phase states. Inverted structured QLED shows green EL emission and a maximum luminance of ~45 cd/m2. This result shows that III-V CQDs can be a good substitute for conventional cadmium-containing CQDs in various opto-electronic applications, e.g., eco-friendly displays. (Un-published results).

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