• Title/Summary/Keyword: selective synthesis

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Total Synthesis of Hepatoprotective Isowogonin and a Synthetic Approach to Wogonin (간보호 효과를 나타내는 Isowogonin의 전합성 및 Wogonin 합성을 위한 반응조건 탐색)

  • Kim, Kwang-Sik;Kim, Hak-Sung
    • YAKHAK HOEJI
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    • v.53 no.6
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    • pp.377-381
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    • 2009
  • Isowogonin, 5,8-dihydroxy-7-methoxyflavone, is a flavonoid isolated from the root of Scutellaria baicalensis Georgi, a medicinal plant traditionally used since the ancient time. It was thought to possess a variety of biological activities, such as antioxidation, anti-inflammation and hepatoprotective effect. But a quantity of isowogonin obtained from Scutellaria baicalensis Georgi is not that enough for in vivo test. There have been no appropriate approaches available for a facile synthesis of isowogonin. So we describe a concise and efficient scheme for synthesis of isowogonin from a commercial available 2,4,6-trimethoxyphenol, which includes the Fries rearrangement and selective demethylation as key steps.

Synthesis and Antiinflammatory Activity of 1.5- and 4.5-Disubstituted Imidazoles

  • Tuyen, Truong-Ngoc;Sin, Kwan-Seog;Kim, Hyun-Pyo;Park, Hae-Il
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.347.4-348
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    • 2002
  • Recently it has been demonstrated that selective cyclooxygenase-2 (COX-2) inhibitors retain the antiinflammatory effect but with markedly reduced GI toxicity compared to non selective inhibitors such as traditional NSAIDs. As a consequence, intense efforts have been made to develop selective COX-2 inhibtors during the last decade. Two compounds in this class. celecoxib and rofecoxib. are already in the market and are proved as potent and selective COX-2 inhibitors with much better gastric tolerance. However. there are still strong domands for a COX-2 inhibitor with improved efficacy and safety profiles. Here we report the synthesis and biological profiles of 1.5- and 4.5-disubstituted imidazole analogues as structural equivalents of cefecoxib and refecoxib. The imidazole analogues are overlapped well whth the 3D srructures of celecoxib and rofecoxib.

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Synthesis of Allyl Functionalized Silacrown Ethers and Their Application - A Review

  • Haque, Md Hasanul;Sohn, Honglae
    • Journal of Integrative Natural Science
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    • v.13 no.2
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    • pp.41-46
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    • 2020
  • A study is reported about the synthesis processes of various silacrown ether by the reaction of alkoxysilanes with polyethylene glycols (PEG) through transesterification. Crown ether-functionalized carbosilane dendrimers and hybrid crown ethers are also discussed. We will also address the solubility enhancement, phase-transfer catalysis of different silacrown as well as their application as Ion-selective electrodes (ISEs) and as active phase of PVC electrodes for the development of potentiometric sensors for detection of alkali-Ions.

A New Chemosensing Ensemble for Colorimetric Detection of Oxalate in Water

  • Tang, Li-Jun;Liu, Ming-Hui
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3159-3162
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    • 2010
  • To realize highly selective recognition of oxalate in water, a new chemosensing ensemble that behaves highly selective colorimetric recognition of oxalate in water at pH 7.4 has been developed. The ensemble was constructed by a pyrrole containing mononuclear copper complex and chromeazurol S. The ensemble shows a highly selective recognition of oxalate through an obvious color change from blue to yellow upon the addition of oxalate, whereas, other dicarboxylates such as malonate, succinate, fumarate, maleate, glutarate, adipate, phthalate, isophthalate and terephthalate do not induce any noticeable color changes. The oxalate recognition process is not significantly affected by other coexisting dicarboxylate.