• Title/Summary/Keyword: pH-dependent solubility

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Structural characterization of As-MIF and hJAB1 during the inhibition of cell-cycle regulation

  • Park, Young-Hoon;Jeong, Suk;Ha, Ki-Tae;Yu, Hak Sun;Jang, Se Bok
    • BMB Reports
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    • v.50 no.5
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    • pp.269-274
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    • 2017
  • The biological activities of macrophage migration inhibitory factor (MIF) might be mediated through a classical receptor-mediated or non-classical endocytic pathway. JAB1 (C-Jun activation domain-binding protein-1) promotes the degradation of the tumor suppressor, p53, and the cyclin-dependent kinase inhibitor, p27. When MIF and JAB1 are bound to each other in various intracellular sites, MIF inhibits the positive regulatory effects of JAB1 on the activity of AP-1. The intestinal parasite, Anisakis simplex, has an immunomodulatory effect. The molecular mechanism of action of As-MIF and human JAB1 are poorly understood. In this study, As-MIF and hJAB1 were expressed and purified with high solubility. The structure of As-MIF and hJAB1 interaction was modeled by homology modeling based on the structure of Ace-MIF. This study provides evidence indicating that the MIF domain of As-MIF interacts directly with the MPN domain of hJAB1, and four structure-based mutants of As-MIF and hJAB1 disrupt the As-MIF-hJAB1 interaction.

Characteristics of Aragonite From Underwater and The Cytotoxicity, Cell Division Disturbance and Induction of Morphological Transformation on BALB/3T3 Cells (일부 지하수에서 얻은 Aragonite의 특성과 BALB/3T3 세포에 대한 세포독성, 세포분열장애 및 형태학적 변이유발)

  • 홍윤철;이훈재
    • Environmental Mutagens and Carcinogens
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    • v.16 no.1
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    • pp.35-42
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    • 1996
  • Aragonite is one of polymorphs of calcium carbonate of which main form is calcite. We found that white precipitate is formed in much amount by boiling underwater of Inchon, Korea and confirmed that it is aragonite. This study is to evaluate the dimensional characteristics, solubility, acid resistance of aragonite and the cytotoxicity, cell division disturbance and cell transforming ability of it on BALB/3T3 cells. The results are as follows: Lengths of the aragonite were reduced to the 72.7% and 22.7% respectively after 5 months and 7 months of intrapleurai injection to the Sprague-Dawley rat. Strong acid such as 1M HCl dissolved the aragonite instantly but weaker acid pH 2.0 or more could not dissolved aragonite easily. The result of cell growth inhibition showed that cell numbers were decreased as log-doses of treatment of the aragonite were increased 24 hours, 48 hours, and 72 hours later. Cell plating efficiency after the aragonite treatment also showed dose-dependent decrease. Multinuclear giant cell formation was increased in the aragonite treated cells until ID$_{50}$ and after the dose the multinucleate cells were decreased, but remained much higher than negative control cells. Morphological transformation assay showed that the aragonite did not induce transformation in all treated doses.

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The Study of Donor-Acceptor Chromophores and Diketopyrrolopyrrole(DPP) Analogues (Donor-Acceptor 발색단과 디케토피롤로피롤(DPP) 유도체에 관한 연구)

  • Kim, HunSoo;Kim, SeungHoi;Park, SooYoul
    • Tribology and Lubricants
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    • v.32 no.5
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    • pp.141-146
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    • 2016
  • The diketopyrrolopyrrole (DPP) pigment is a bicyclic 8-π-electron system containing two lactam units. Typical DPP derivative pigments have melting points of over 350°C and very low solubility in most solvents, and show absorption in the visible region with a molar extinction coefficient of 33,000 dm2mol−1 and strong photoluminescence with maxima in the range 500–600 nm. X-ray structure analyses of DPP show that the whole molecule is almost in one plane. The phenyl rings are twisted out of the heterocyclic plane and the intermolecular hydrogen bonding between neighboring lactam NH and carbonyl units influences the structure of the DPP pigment in the solid state. In this study, mono-N-alkylation and mono-N-arylation were undertaken for Pigment Red 264 or Pigment Orange 73 with alkyl halide and aryl halide, respectively, in the presence of sodium tert-butoxide as a base catalyst to improve the solubility of DPP pigments and their application as CO2 indicators. The synthetic yield was in the range 11–88%. The indicator dyes are highly soluble in organic solvents and shows pH-dependent absorption (λmax 501 and 572 nm for the protonated and deprotonated forms, respectively) and emission (λmax 524 and 605 nm for the protonated and deprotonated forms, respectively) spectra. The mono-N-alkylated and mono-N-arylated DPP pigment was identified by 1H-NMR (1H-Nuclear Magnetic Resonance Spectrometer), FT-IR (Fourier Transform Infrared Spectroscopy), and MS (Mass Spectrometry). According to the results of color and hue properties obtained by a color matching analyzer, the synthesized DPP pigment material can be used as a CO2 indicator.

Investigation of Cadmium and Zinc Interactions in Soils using Desorption Isotherms

  • Lee, Jin-Ho;Doolittle, James J.
    • Korean Journal of Environmental Agriculture
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    • v.25 no.2
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    • pp.157-163
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    • 2006
  • Investigation of Cd and Zn availability in four different soils as affected by the interactions of these two heavy metals was conducted using the metal desorption quantity-intensity (Q/I) isotherms. The soils were artificially contaminated with proper concentrations of Cd and Zn as $CdSO_4\;and\;ZnSO_4$ solutions. DTPA (diethylene triamine pentaacetic acid) - extractable and water-extiactable Cd or Zn from the soils were used as $Q_{Cd}\;or\;Q_{Zn}\;and\;I_{Cd}\;or\;I_{Zn}$ factors, respectively. The coefficient of determination for Cd and Zn desorption Q/I linear regression in the soils ranged from 0.947 to 0.999, which indicated that Q and I factors were closely correlated. The buffering capacity of Cd, $BC_{Cd}$, in the soils decreased with increasing Zn treatments, and the $BC_{Cd}$ values were ranged between 205.8 and 2255.6. The decreases of $BC_{Cd}$ values were mainly dependent upon the increases of $I_{Cd}$ factors. However, Zn buffering capacity. $BC_{Zn}$ decreased with increasing Cd treatments in acidic soils, and increased in neutral and calcareous alkaline soils. The $BC_{Cd}$ values were ranged from 143.2 to 6158.0. The values of $BC_{Zn}$ as influenced by the treatments of Cd were also controlled by the solubility of water-extractable Zn, $I_{Zn}$ factor. The solubility of water-extractable Cd and Zn was significantly dependent upon the changes of soil pH that were impacted by the treatment of Zn and Cd, respectively. Also, the availability of Cd was higher than Zn availability in the acidic and neutral soils, but Zn was higher than Cd in the calcareous alkaline soil.

Effect of Maleylation on Physicochemical Properties of Soybean Glycinin

  • Shin, Weon-Sun;Park, Soo-Jin;Park, Chun-Wuk;Kim, Kang-Sung
    • Macromolecular Research
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    • v.15 no.7
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    • pp.671-675
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    • 2007
  • Soybean proteins appear to harbor a great deal of potential as functional ingredients due to the fact that they are composed of highly bioavailable peptides and amino acids. To develop drink- or gel-type foods formulated with soybean protein, the physicochemical properties of intact and chemically modified soy glycinin were assessed. Maleylation to soy glycinin altered the surface charges of glycinin via the modification of lysine residues, and subsequently generated the dissociation of glycinin subunits owing to the increase in charge repulsion. This modification thus improved the solubility of glycinin, particularly under acidic pH conditions. It is worthy of note that maleylation increased the susceptibility of the basic subunits of mTGase and the formation of a substantial quantity of molecules at a low protein solution concentration. The results of dynamic rheological studies indicated that the 5% intact glycinin progressively formed the gel with mTGase treatment in a concentration-dependent manner, but maleylated-glycinin did not.

A Basic Study on the Effective Management for MSWI Fly Ash (II) - Effect of Leaching Parameter - (소각 비산재의 적정처리를 위한 기초연구(II) - 용출인자의 영향 -)

  • Kim, Jin-Beom;Lee, Woo-Keun;Shim, Yeong-Ju
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.7
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    • pp.1357-1364
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    • 2000
  • Our study was performed to evaluate the effect of leaching parameters including the physicochemical characteristics and the fractionated composition of heavy metals on the release of heavy metals in fly ash discharged from MSWI. Leaching parameters such as pH, CEC, particle size, and exchangeable fraction among the fractional composition classified by sequential extraction procedure are considered. The leaching rate of heavy metal released by KSLT method is largely dependent on the pH of fly ash. The effect of pH on the release of heavy metals is different from elements. It appears that the leaching rate of cadmium and copper decreases with increasing pH, while lead and zinc increases at the condition of neutral or strong alkali condition, which suggests that the leaching of heavy metals are limited by the solubility. It is found that the effect of CEC is similarly to that of pH, $D_{10}$ among the particle size of fly ash is negative correlated with the concentration of heavy metals leached by KSLT method. In the case of exchangeable fraction, the leaching rate of heavy metals is linearly correlated with the exchangeable fraction for the fly ash below 40 meq/l00g of CEC, but not related out of the range.

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Immediate Drug Release Enhancement of Nateglinide Using Fumaric Acid (푸마르산을 이용한 나테글리니드 함유 속방출형 제형의 약물방출 개선에 관한 연구)

  • Lee, Sung-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.506-512
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    • 2017
  • The purpose of this study was to improve release rate and bioavailability of nateglinide formulation. Polymorphism selection and particle size control were performed to enhance formulation dissolution rate, and a pH modifier was included in the formulation to overcome pH-dependent solubility of nateglinide. The enhanced dissolution rate was characterized by using a dissolution test. The results showed that H-type raw material had a higher dissolution rate than that of B-type raw material. There was 6.2% difference in dissolution between the two materials at 60 min. With regard to particle size, raw material with a $1.13{\mu}m$ particle size showed a 20% faster release rate than that of raw material with a $2.28{\mu}m$ particle size. Furthermore, fumaric acid was included in formulation as a pH modifier. That addition produced a greater than 50% improvement in dissolution rate. In conclusion, dissolution rate of nateglinide can be enhanced by optimizing its polymorphism and particle size; moreover, a synergistic effect on the enhancement of dissolution rate is obtained by including fumaric acid, a pH modifier, in the formulation.

Characteristics of the Purple Pigment Compound in Halophytic Plant, Suaeda japonica (내염성 식물 칠면초 (Suaeda japonica )가 갖는 자색 색소의 특징)

  • Chung, Sang-Ho
    • Proceedings of the Korea Contents Association Conference
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    • 2013.05a
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    • pp.361-362
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    • 2013
  • As one of the steps toward understanding how the plant is well adapted to strongly saline habitats, the purple pigment compound that is accumulated in Suaeda japonica was extracted and characterized. The extracted pigment compound exhibited typical characteristics of betacyanin that were represented by water solubility, pH- and temperature-dependent color changes, sensitivity to light, UV-Vis spectra, and gel electrophoretic migration pattern. LC-MS of the extracted pigment compound showed the presence of two major protonated molecular ions ($[M+H]^+$) at m/z 651.1 and m/z 827.1. According to the DPPH assay, it was found to have an antioxidant activity that is linearly increased in proportion to the reaction time for up to 30 min, and the activity was comparable to that of control BHA at 9.0 mg/ml. The cytotoxic activity against several tumor cell lines was also examined following the MTT assay. The significant growth inhibitory effect was observed on two tumor cell lines, SW-156 (human kidney carcinoma) and HEC-1B (human endometrial adenocarcinoma). Probably, the pigment compound may function as an osmolyte to uphold halotolerant physiological processes in saline environment.

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Features and Functions of Purple Pigment Compound in Halophytic Plant Suaeda japonica : Antioxidant/Anticancer Activities and Osmolyte Function in Halotolerance

  • Chung, Sang Ho
    • Korean Journal of Plant Resources
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    • v.31 no.4
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    • pp.342-354
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    • 2018
  • Suaeda japonica is a halophytic plant that lives in mudflat at intertidal zone of western and southern coastal areas of Korea. The seawater-living plants showed a purple color during their whole life. In contrast, freshwater-living plants displayed a green color in leaves. When seawater-living plants were transferred to potting soil, the purple color was gradually changed to green in the leaves. The extracted purple pigment compound exhibited typical characteristics of betacyanin that were represented by water solubility, pH- and temperature-dependent color changes, sensitivity to light, UV-Vis spectra, and gel electrophoretic migration pattern. The LC-MS analysis of the extracted pigment compound showed the presence of two major protonated molecular ions ($[M+H]^+$) at m/z 651.1 and m/z 827.1. Antioxidant activity of the pigment compound was determined using stable free radical DPPH assay. It was found to have an antioxidant activity that is linearly increased in proportion to the reaction time for up to 30 min, and the activity was comparable to that of control BHA at 9.0 mg/ml. The anticancer activity against several tumor cell lines was also examined following the MTT assay. The significant growth inhibitory effect was observed on two tumor cell lines, SW-156 (human kidney carcinoma) and HEC-1B (human endometrial adenocarcinoma). Probably, the pigment compound may function as an osmolyte to uphold halotolerant physiological processes in saline environment.

Extraction of Cd and Pb from Soil by Anionic Surfactant and Ligand NaI (NaI 리간드화 계면활성제에 의한 토양내 Cd과 Pb 추출 연구)

  • Heo, Jung-Hyun;Jeong, Seung-Woo
    • Journal of Soil and Groundwater Environment
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    • v.13 no.5
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    • pp.74-80
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    • 2008
  • Heavy metals, Cd and Pb, in soil were extracted by using anionic surfactants such as AOS (alpha olefin sulfonate), SDS (sodium dodecyl sulfate), and LAS (linear alkyl benzene sulfonic acid). Metal extractability from soil was affected by the carbon number and solution pH of surfactants. LAS showed higher metal extractability due to the acidic solution condition. Although SDS has a fewer carbon number than AOS, it would produce smaller micelles and resulted in more efficient extraction of metals by increased soil contact. Cd extractability of surfactant was twice enhanced by adding NaI as a ligand. However, Pb extractability of surfactant was sometimes reduced by adding NaI. Those ligand effects were dependent on solubility of metal-ligand. The column experiment also showed that SDS having smaller micelles resulted in higher metal extractability than AOS.