• Title/Summary/Keyword: fine chemicals

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Monosaccharide as a Central Scaffold Toward the Construction of Salicylate-Based Bidentate PTP1B Inhibitors via Click Chemistry

  • Tang, Yan-Hui;Hu, Min;He, Xiao-Peng;Fahnbulleh, Sando;Li, Cui;Gao, Li-Xin;Sheng, Li;Tang, Yun;Li, Jia;Chen, Guo-Rong
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.1000-1006
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    • 2011
  • The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold, whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged $IC_{50}$ value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

Chemoselective Alkylation of Aromatics with Benzyl Alcohol over Mesoporous ZSM-5

  • Jin, Hailian;Ansari, Mohd Bismillah;Jeong, Eun-Young;Park, Sang-Eon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.200-200
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    • 2011
  • Hierarchical mesoporous ZSM-5 with enhanced mesoporosity was synthesized by microwave through the rapid assembly via ionic interaction between sulfonic acid functionalized ZSM-5 nano particles and cationic surfactant. The catalytic performance of enhanced accessibility due to mesoporosity and acidity were investigated in the alkylation of mesitylene with benzyl alcohol as alkylating agent. The effect of mole ratio of aromatic with benzyl alcohol, reaction time and alkylation agent were also studied. The enhanced mesoporosity and acidity of sulfonic acid functionalized mesoporous ZSM-5 induced activity enhancement compared with non-functionalized mesoporous ZSM-5, sulfonic functionalized mesoporous ZSM-5 synthesized by hydrothermal method and conventional microporous ZSM-5. The sulfonic acid functionalized mesoporous ZSM-5 showed much higher chemoselectivity of benzylated mesitylene than others, whereas the others mainly show dibenzyl ether as product. This significant difference in catalytic selectivity was resulted from the existence of mesopores, which definitely allowed the benzylation in mesopores.

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Effects of Cu and Ni Additives for Hydrogen Storage and Release of Fe-based Oxide Mediums (Fe-계 산화물 매체의 수소 저장 및 방출을 위한 Cu 및 Ni 첨가제의 효과)

  • Kim, Hong-Soon;Cha, Kwang-Seo;Lee, Dong-Hee;Yoo, Byoung-Kwan;Kang, Kyoung-Soo;Park, Chu-Sik;Kim, Young-Ho
    • Journal of Hydrogen and New Energy
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    • v.19 no.5
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    • pp.394-402
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    • 2008
  • The Effects of Cu or Ni additives co-added with Ce/Zr mixed oxides to Fe-based oxide mediums were investigated for the purpose of the replacement of Rh, a precious metal additive, in terms of hydrogen storage(reduction by hydrogen) and release(water splitting). From the results of temperature programmed reduction(TPR), initial reduction rate of iron oxide in the mediums was greatly increased with the addition of Cu, similar to that of Rh. For isothermal redox reaction of 10 cycles, the total amounts of hydrogen evolved in water splitting steps for the mediums added with Cu or Ni were highly maintained at ca. 7 mmol/g-material, even though the oxidation rates were slightly lower than that for the medium added with Rh. This result suggests that the replacement of Rh to Cu or Ni is possible as a co-additive for Fe-based oxide mediums.

Organotemplate-free synthesis of ZSM-5 membrane for pervaporation dehydration of isopropanol

  • Li, Jiajia;Li, Liangqing;Yang, Jianhua;Lu, Jinming;Wang, Jinqu
    • Membrane and Water Treatment
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    • v.10 no.5
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    • pp.353-360
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    • 2019
  • ZSM-5 membrane was prepared on tubular macroporous ${\alpha}$-alumina support using a different synthesis route. The effects of organic template agent and Si/Al ratio of the synthesis gel on morphology, structure, and separation performance of the ZSM-5 membrane used for dehydration of isopropanol were investigated. High water perm-selectivity ZSM-5 membrane with a thickness of about $3.0{\mu}m$ and a low Si/Al ratio of 10.1 was successfully prepared from organotemplate-free synthesis gel with a molar composition of $SiO_2$ : $0.050Al_2O_3$ : $0.21Na_2O$ : NaF : $51.6H_2O$ at $175^{\circ}C$ for 24 h. The ZSM-5 membrane exhibited high pervaporation performance with a flux of $3.92kg/(m^2{\cdot}h)$ and corresponding separation factor of higher than 10,000 for dehydration of 90 wt.% isopropanol/water mixture at $75^{\circ}C$.

Fuctionalization of SBA-16 Mesoporous Materials with Cobalt(III) Cage Amine Complex

  • Han, Sang-Cheol;Sujandi, Sujandi;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.9
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    • pp.1381-1384
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    • 2005
  • Surface modification of tridimensional cubic mesoporous silica, SBA-16, was investigated with pendant arm functionalized cobalt diaminosarcophagine (diAMsar) cage complex which covalently grafted onto the silica surface through the silication with sylanol group. The spectroscopic results showed that the mesoporous structure was preserved under the $[Co(diAMsar)]^{3+}$ grafting reaction condition. Successful grafting prevented the cobalt diAMsar cage from leaching out from the SBA-16 support.

2-Aminothiazolinium Based Tripodal Receptors:Synthesis and Recognition of Oxoanions

  • Nguyen, Quynh Pham Bao;Le, Thanh Nguyen;Kim, Taek-Hyeon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.8
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    • pp.1743-1748
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    • 2009
  • Novel 2-aminothiazolinium based tripodal receptors were designed and synthesized. The binding property of these receptors toward various anions was investigated by the isothermal titration calorimetry (ITC) method. Receptor 4 recognized the acetate anion with 1:1 stoichiometry, whereas it bound the other oxoanions such as sulfate and phosphate in complex modes. By modifying the phenyl groups at the 4-position of the thiazoline rings of the tripodal receptor 4 to induce a mutual aromatic stacking interaction among the three ligands, receptor 10 showed totally different binding behavior, which gave rise to the 1:1 binding mode for the sulfate anion. This result was confirmed by ESI MS spectrometry.

Anion Recognition by a Simple Colorimetric Benzthiazole-Based Receptor

  • Kang, Sung-Ok;Nguyen, Quynh Pham Bao;Kim, Taek-Hyeon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2735-2738
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    • 2009
  • A simple colorimetric anion chemosensor based on 2-amino-6-nitrobenzothiazole was synthesized. The addition of tetrabutylammonium (TBA) salts of $F^-,\;{CH_3COO}^-,\;and\;{H_2PO_4}^-$ to the solution of receptor 3 caused dramatic and clearly observable color changes from light to dark yellow due to the deprotonation process which is totally different from previously reported receptors based on the same motif. According to the basicity of the anions, the sensitivity of receptor 3 towards various anions decreased in the following order: ${CH_3COO}^-\;>\;F^-\;>\;{H_2PO_4}^-$.