• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1825-1826
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• 2012

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1203-1205
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• 2007

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1623-1624
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• 2013

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2063-2069
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• 2011

We studied the interaction of 3,3',3'',3'''-ethylenetetrakis-4-hydroxycoumarin (EHC) with bovine serum albumin (BSA) in acetate buffer and phosphate buffer with different pH values by UV-vis absorption spectrometry and fluorescence spectrometry respectively. It was found that the pH values of the buffer solutions had an effect on the interaction process. In acetate buffer of pH 4.70, the carbonyl groups in EHC bound to the amino groups in BSA by means of hydrogen bond and van der Waals force, which made the extent of peptide chain in BSA changed. By contrast, in phosphate buffer of pH 7.40, hydrophobic force played a major role in the interaction between EHC and BSA, while the hydrogen bond and van der Waals force were also involved in the interaction. The results of spectrometry indicated that BSA could enhance the fluorescence intensity of EHC by forming a 1:1 EHC-BSA fluorescent complex through static mechanism at pH 4.70 and 7.40 respectively. Furthermore, EHC bound on site 1 in BSA.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3611-3616
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• 2010

Five new 4- or 8-substituted-7-hydroxycoumarin derivatives (1-5) were synthesized as fluorescent sensors for metal ions. Fluorescent changes and selectivity for metal ions were compared based on the introduction of different ligands and/or testing with different substitution positions of 7-hydroxycoumarin in aqueous solution. Especially, probes 2, 3 and 5 displayed large fluorescence enhancements with $Zn^{2+}$ and $Cd^{2+}$. Probes 2 and 3 showed moderate selectivity for $Zn^{2+}$ over $Cd^{2+}$. On the other hand, probe 4 showed large fluorescence quenching effects upon the addition of $Ag^+$ and $Hg^{2+}$.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.686-696
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• 2003

Ethyl (coumarin-4-oxy)acetate 1 was prepared through the reaction of 4-hydroxycoumarin with ethyl bromoacetate. Compound 1 was allowed to react with hydrazine hydrate to produce coumarin-4-oxyacetic hydrazide 2. The synthesis of N-(arylidene and alkylidene)-coumarin-4-oxyacetic hydrazones 3-20 was performed. The preparation of 2-substituted-3-[(coumarin-4-oxy) acetamido]thiazolidinones 21-26 and 2-[(coumarin-4-oxy )methyl]-4-acetyl-5-substituted-$\Delta^2$-1,3,4-oxadiazolines 27-33 was performed by the reaction of the hydrazones 3, 4, 7, 9, 12, 14 with mercaptoacetic acid and the hydrazones 3, 4, 5, 7, 12, 15, 16 with acetic anhydride, respectively. The antiviral activities, cytotoxicities and structure-activity relationship (SAR) towards different microorganisms of the prepared compounds were studied.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.662-665
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• 2011

Highly efficient, three-component condensation of aromatic aldehyde, malononitrile and 4-hydroxycoumarin promoted by neat silica gel at room temperature is described. The method offers an excellent alternative to the synthesis of 3,4-dihydropyrano[c]chromenes. The reactions are fast and clean, and the products are obtained with good yield and purity.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4286-4290
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• 2011

A novel catalytic synthesis of biscoumarins from 4-hydroxycoumarin and aromatic aldehydes has been developed. The reaction occurs in ethanol in the presence of tetrabutylammonium hexatungstate $[TBA]_2[W_6O_{19}]$ as catalyst to give the corresponding products in high yields. This new approach has short reaction times, clean reaction profiles, and simple experimental and workup procedures. Moreover, the catalyst can be easily recovered by filtration and used at least three times with only slight reduction in its catalytic activity.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4239-4242
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• 2012

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1625-1632
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• 2014

A concise and efficient one-pot synthesis of chroman-2,4-dione-based HKA derivatives by three component reaction of HKAs, triethoxymethane and 4-hydroxycoumarin derivatives under solvent-free and catalyst-free conditions is described. This protocol has many advantages, in that the GAP (Group-Assistant-Purification) chemistry process is involved in this method. As a result, the experimenter can avoid cumbersome process steps such as traditional chromatography and recrystallization purifications. The desired products can be easily obtained by washing the crude products with 95% EtOH.