• Title/Summary/Keyword: $IC_50$

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Physiological Effect of Korean Black Soybean Pigment (한국산 검정콩 색소의 생리활성효과)

  • Son, Jun-Ho;Choung, Myoung-Gun;Choi, Hee-Jin;Jang, Un-Bin;Son, Gyu-Mok;Byun, Myung-Woo;Choi, Cheong
    • Korean Journal of Food Science and Technology
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    • v.33 no.6
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    • pp.764-768
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    • 2001
  • Physiological effects of Korean black soybean pigment were investigated. Major anthocyanin pigments of Korean black soybean were extracted with 1% HCl for 24 hours at $4^{\circ}C$. Inhibitory effects of angiotensin converting enzyme ($IC_{50}$) were 0.22 mg/mL (Kumjungkong #1), 0.28 mg/mL (Ilpumkumjungkong) and 0.38 mg/mL (Milyang #95). Inhibitory effects xanthine oxidase ($IC_{50}$) were 0.118 mg/mL (Kumjungkong #1), 0.165 mg/mL (Ilpumkumjungkong) and 0.163 mg/mL (Milyang #95). The cPLA2 inhibitory effects ($IC_{50}$) were $19.7\;{\mu}g/mL$, $10.7\;{\mu}g/mL$ and $25.3\;{\mu}g/mL$. The cytotoxic effects of anthocyanins from Milyang #95 were 66.0% against human colon cell line (HT29), 58.2% against human liver cell line (HepG2) and 64.4% against mouse liver cell line (Hepa), respectively.

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Biological Activities of Magnolia denudata Desr. Flower Extracts (목련(Magnolia denudata Desr.) 꽃 추출물의 생리활성)

  • Nho, Jin-Woo;Hwang, In-Guk;Joung, Eun-Mi;Kim, Hyun-Young;Chang, Seong-Jun;Jeong, Heon-Sang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.11
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    • pp.1478-1484
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    • 2009
  • The antioxidant, antiproliferation, and nitrate synthesis inhibitory effects of Magnolia denudata extracts (ME) were evaluated. The ME was extracted with 70% (v/v) ethanol and fractionated with solvents of hexane, chloroform, ethyl acetate, n-buthanol and aqueous. The ethyl acetate fraction contained the highest phenolic and flavonoid contents of 427.10 mg garlic acid eq/g and 356.05 mg catechin eq/g, respectively. The ethyl acetate fraction showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity with a 50% inhibition concentration ($IC_{50}$) of 0.20 mg/mL and total antioxidant activity was 0.90 mg AA eq/100 mg. From the results of cytotoxic effects of HCT116, NCL-H460, and HepG2 human cancer cells by MTT assay on the ME and its solvent fraction, chloroform fraction showed the highest cytotoxic effect ($IC_{50}$ value: 0.14, 0.37, and 0.41 mg/mL, respectively). Nitrate synthesis inhibitory effect of ME and its solvent fractions on nitric oxide synthase activity in LPS stimulated RAW 264.7 cells were decreased in dose-dependent manners, and $IC_{50}$ value of hexane and chloroform fractions were 0.39 and 0.49 mg/mL, respectively.

The study on the DC Ic measurement and AC loss in the 22.9kV, 50MVA HTS power cable (22.9kV/50MVA급 고온초전도 전력케이블의 DC Ic 측정 및 교류손실에 관한 연구)

  • Choi, Suk-Jin;Lee, Sang-Jin;Sim, Ki-Deok;Cho, Jeon-Wook
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.808-809
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    • 2008
  • 22.9kV 50MVA HTS power cable has been developed and tested by Korea Electrotechnology Research Institute and LS Cable Company and it was supported by a grant from Center for Applied Superconductivity Technology of the 21st Century Frontier R&D Program. In this paper, DC Ic of 100m HTS cable which is installed at Kochang testing station was measured and analyzed. A measurement technique of DC Ic used by resistance and inductance removal method is established. The HTS power cable is composed of 2 layers for transmission and 1 layer for shield. For the analysis of AC losses in an HTS power cable, 2-dimensional numerical calculation was carried out to define the magnetic field distribution. We calculated the magnetization losses in the HTS core of that cable from these fields. These calculated results are in accordance with those of experiment.

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Synthesis of Nonclassical Quinazolinone Antifolates as Thymidylate Synthase Inhibitors and Their Antitumor Activity In Vitro

  • Baek, Du-Jong;Kang, Tae-Beom;Kim, Hyun-Ju
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1898-1906
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    • 2004
  • Nonclassical quinazolinone analogs I, II, and III, in which the glutamic acid moiety of the classical antifolates is substituted by phenylglycine, phenylalanine or aminobenzoic acid and their methyl esters, were synthesized and evaluated as lipophilic inhibitors of thymidylate synthase (TS). The target compounds were generally potent inhibitors of L. casei and human TS with $IC_{50}$ values within the narrow range of 0.2-10 ${\mu}$M and 0.003-0.03 ${\mu}$M, respectively. Further, most of the target compounds showed cytotoxicity against tumor cell lines of murine and human origin with $IC_{50}$ values of as low as 0.050 ${\mu}$M. Substitution of another hydroxyl or carboxylic acid/ester group at the phenyl ring further increased the potency of TS inhibition and cell growth inhibition. Most effective were compounds If and Ic in which extra carboxylic acid/ester was present at the phenyl ring with nanomolar $IC_{50}$ values of 0.0044 and 0.0093 ${\mu}$M against human TS and submicromolar cytotoxic growth inhibition against all four tumor cell lines.

Tumor cell growth inhibition and antioxydative activity of flavonoids from the stem bark of Cudrania tricuspidata (꾸지 뽕나무로부터 분리한 flavonoid계 화합물의 암세포성장 저해 및 항산화 활성)

  • Lee, In-Kyoung;Song, Kyung-Sik;Kim, Chang-Jin;Kim, Hwan-Muk;Oh, Goo-Taeg;Yoo, Ick-Dong
    • Applied Biological Chemistry
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    • v.37 no.2
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    • pp.105-109
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    • 1994
  • Five cytotoxic and antioxidative flavonoids were isolated from the stem bark of Cudrania tricuspidata by consecutive purification using HP-20, silicagel and prep-HPLC. They were identified as taxifolin, orobol, eriodictyol, dihydrokaempferol and steppogenin by means of spectral studies. The antioxidative activities $(IC_{50})$ assayed by TBA method of these compound $1{\sim}5$ to were 6, 3, 3, >50, and $10\;{\mu}g/ml$, respectively. The effect on the growth inhibition $(IC_{50})$ of these compounds against P388 cell line were found to be 0.18, 3.3, 15 and $6.2\;{\mu}g/ml$, respectively in the order of compound 2 to 5.

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Development of Antitoxic Agents from Sophora flavescens Ait. (고삼 추출물을 이용한 해독물질의 개발)

  • 양희태;정승일;이영철;윤경아;백승화
    • The Korean Journal of Food And Nutrition
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    • v.15 no.1
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    • pp.36-41
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    • 2002
  • The aim of this study was to assess the antitoxic compounds, flavanones(Leachianone A=LA and Sophoraflavanone G=SFG), from Sophora flavescens(S. flavescens). We investigated the possibility of antitoxicity of LA and SFG against NIH 3T3 fibroblasts cell lines using calorimetric MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl -2H-tetra-azolium bromide] assay. The results were as follows : After cadmium was treated against NIH 3T3 cell lines, we determined IC$\_$50/. Accordingly we have examined the detoxification effects of S. flavescens, LA and SFG under cadmium IC$\_$50/=12.5$\mu$M and was carried out to observe morphological changes by the light microscopic study In NIH 3T3 cells, Sophora flavescens, LA, SFG and LA + SFG showed inhibitory effects on the cytotoxicity of cadmium and these detoxication effects increased in proportion to the concentration of these drugs. These results suggest that LA and SFG from S. flavescens retain a potential antitoxic activity.

Quantifying the Interactive Inhibitory Effect of Heavy Metals on the Growth and Phosphorus Removal of Pseudomonas taeanensis

  • Yoo, Jin;Kim, Deok-Hyun;Oh, Eun-Ji;Chung, Keun-Yook
    • Korean Journal of Soil Science and Fertilizer
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    • v.51 no.1
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    • pp.35-49
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    • 2018
  • This study was initiated to quantitatively evaluate the effects of five heavy metals (Cd, Cu, Zn, Pb, and Ni) on growth and P removal efficiencies of Pseudomonastaeanensis, known as the phosphorus accumulating microorganism. The heavy metals were added individually and with the binary mixture to the batch culturing system of Pseudomonastaeanensis. $IC_{50}$ and $EC_{50}$ were used to quantitatively evaluate their effects on the growth and phosphorus removal efficiency of Pseudomonas taeanensis in those treatments. Additionally, additive index value method was used to evaluate the interactive effects of heavy metals for Pseudomonas taeanensis in this study. As those heavy metals were singly added to Pseudomonastaeanensis, the greatest inhibitory effect on its growth and P removal efficiency was observed in Cd, whereas, the smallest effect was found in Ni. As the concentrations of all heavy metals added were gradually increased, its growth and P removal efficiency was correspondingly decreased. Specifically, $IC_{50}$ of Pseudomonas taeanensis for Cd, Cu, Zn, Pb, and Ni were $0.44mg\;L^{-1}$, $5.12mg\;L^{-1}$, $7.46mg\;L^{-1}$, $8.37mg\;L^{-1}$ and $14.56mg\;L^{-1}$, respectively. The P removal efficiency of Pseudomonas taeanensis was 81.1%. $EC_{50}$ values of Pseudomonas taeanensis for Cd, Cu, Zn, Pb, and Ni were $0.44mg\;L^{-1}$, $4.08mg\;L^{-1}$, $7.17mg\;L^{-1}$, $8.90mg\;L^{-1}$ and $11.26mg\;L^{-1}$, respectively. In the binary treatments of heavy metals, the lowest $IC_{50}$ and $EC_{50}$ were found in the Cd + Cu treatment, whereas, the highest $IC_{50}$ and $EC_{50}$ were found in the Zn + Pb and Pb + Ni treatments, respectively. Most of the interactive effects for the binary mixture treatments of heavy metals were antagonistic. Based on the results obtained from this study, it appears that they could provide the basic information about the toxic effects of the respective individual and binary treatments of heavy metals on the growth and P removal efficiency of other phosphorus accumulating organisms.

Antioxidative and Antiaging Effects of Sorbus commixta Twig Extracts (마가목 가지 추출물의 항산화 및 항노화에 관한 연구)

  • Lim, Gyu-Nam;Park, Min-A;Park, Soo-Nam
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.4
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    • pp.482-490
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    • 2011
  • In this study, the antioxidative effects and inhibitory effects on tyrosinase and elastase of Sorbus commixta (S. commixta) twig extracts were investigated. The aglycone fraction of S. commixta twig extract showed the prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity($FSC_{50}$, $13{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities of S. commixta twig extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated by the luminol-dependent chemiluminescence assay. The 50 % ethanol extract among extracts showed the most prominent ROS scavenging activity ($OSC_{50}$, $0.189{\mu}g/mL$). The cellular protective effects of extract/fractions of S. commixta twig on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The 50 % ethanol extract and ethyl acetate fraction showed the cellular protective effects against ROS in a concentration dependent manner ($5{\sim}50{\mu}g/mL$). The inhibitory effect of S. commixta twig extract on tyrosinase was investigated to assess the whitening efficacy. The ethyl acetate ($IC_{50}$, $113.2{\mu}g/mL$) and aglycone fraction($IC_{50}$, $105.3{\mu}g/mL$) on tyrosinase showed more remarkable inhibitory effect than arbutin($IC_{50}$, $226.88{\mu}g/mL$), known as the whitening agent. The inhibitory effect of aglycone fraction ($IC_{50}$, $6.9{\mu}g/mL$) on elastase was simillar to quercetin($IC_{50}$, $6.1{\mu}g/mL$), flavonoid known as reference compound. These results indicate that extract/fractions of S. commixta twig can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. S. commixta twig extracts can be applicable to new functional cosmetics for anti-aging products.

Evaluation of the cosmeceutical activity of ethanol extracts from Perilla frutescens var. acuta (자소엽 에탄올 추출물의 향장학적 활성 평가)

  • Park, Do-Young;Lee, Ki-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.513-517
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    • 2017
  • The purpose of this study was to investigate the antioxidative and anti-inflammatory activities of ethanol extracts from Perilla frutescens var. acuta by varying the concentration of ethanol at 30, 50, 70, and 90% to utilize the effective extract of Perilla frutescens as a cosmetic and pharmaceutical material. In the DPPH antioxidant activity test, the 70% ethanol extract showed the highest activity with an IC50 of 680.98ppm. ABTS showed a high activity in the 50% ethanol extract and the 70% ethanol extract with an IC50 of 646.94 and 661.94 ppm, respectively. Each ethanol extract showed antioxidant activity at a certain concentration (100-10000 ppm), but did not show any significant relationship with the ethanol extract concentration. In RAW 264.7 macrophages induced by LPS, each of the ethanol extracts showed reduced NO production in all extracts, and more than 50% ethanol extract (10000ppm) inhibited nitric oxide formation by 85% or more. In particular, the 70% ethanol extract showed 90% or more nitric oxide production inhibition. In addition, the MTT assay showed no cytotoxicity at all concentrations (1250-10000 ppm) of each extract. In this study, the ethanol extract of Perilla frutescens var. acuta has antioxidant activity and anti-inflammatory activity that is dependent on the concentration at each extraction concentration.

Design of VCO(Voltage Controlled Oscillator) for mobile communication with a built-in voltage regulator (전압 레귤레이터를 내장한 이동통신용 VCO(Voltage Controlled Oscillator) 설계)

  • Cho, Hyon-mook
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.4
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    • pp.76-84
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    • 1997
  • In this paper, one of the core components of a mobile communication system, VCO(Voltage Controlled Oscillator) IC is designed. The VCO IC was designed, have realized as LC turned oscillator using varicap. LC sinusoidal tuned oscillator generally requires external inductors and thus remainding circuit is implemneted in monolithic IC. The circuit is fabricated using an 15 mask IC process and has a die size of 1150um${\times}$780um. The tests showed that VCO was operated at frequencies in the regions between 880MHz-915MHz in the control voltage range of 1V to 3V at 5V supply voltage and as the power supply was varied from 4.5V to 5.5V, the frequency varied 425KHz/V. The VCO IC has frequency shift of 1.97MHz/T, carrier level of -7dBm and power consumption of 16.7mA. Also it has phase noise of -80dBc/Hz, offset at 50KHz and harmonic response of center frequency is -41dBm. For the future development of the transceiver 1 chip, the previously mentioned external devices need to be incorporated into Si MMIC.

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