نتایج جستجو برای: coumarin

تعداد نتایج: 3800  

2012
J. Thipperudrappa

The effect of three aromatic amines namely aniline (AN), dimethyl aniline (DMAN) and diethyl aniline (DEAN) on emission properties of a coumarin derivative 6-methyl-3azidoacetyl coumarin (6M3AAC) in acetonitrile was studied by means of steady state fluorescence spectroscopy. The quenching of fluorescence intensity was observed in the presence of amines. The quenching process was characterized b...

Journal: :Molecules 2009
Graziella Tocco Carlo Maria Carbonaro Gabriele Meli Gianni Podda

The immobilization of some coumarin derivatives on modified poly(ethylene glycol)s is reported and the influence of the polymeric support on the photoluminescence activity of the compounds is discussed. Upon ultraviolet excitation, the derivatives showed coumarin-related emission properties whose peak position and efficiency depended on the loading of the polymer and on the mesomeric effects of...

Journal: :Chemical communications 2014
Chih-Hsuan Tai Chun-Ping Lu Shih-Hsiung Wu Lee-Chiang Lo

We have synthesized and evaluated two self-immobilizing, turn-on fluorescent probes carrying a coumarin molecular framework for imaging intracellular human steroid sulfatase (STS) activity. The 8-fluoromethyl coumarin derivative, which gives stronger fluorescence response in the incubation study with STS preparations, was successfully applied to visualize STS activity in cells.

Journal: :Chemical & pharmaceutical bulletin 2001
Y Shikishima Y Takaishi G Honda M Ito Y Takfda O K Kodzhimatov O Ashurmetov K H Lee

The methanol extract of the dried aerial parts of Prangos tschimganica gave three new coumarin derivatives and 30 known coumarin derivatives. Their structures were established on the basis of chemical and spectroscopic evidence. Absolute configuration of the isolated compounds were determined by using a modified Mosher's method. Some of the isolated compounds showed anti-HIV activity.

2015
V. t. Angelova V. Valcheva G. stavrakov

The present article describes the evaluation of the in vitro activity against M. tuberculosis H37Rv of eight coumarin-derived aminoalcohols and amidoamines. Seven of the compounds display activity between 10 and 20 times higher than the classicall anti-TB drug ethambutol. The combination of coumarin scaffold with aminoalcohol fragments gave the most promising activities with MICs up to 0.32 μM.

2012
Suvarna G. Kini Shivani Choudhary Muhammad Mubeen

During the last 2 decades, the study of the biological activities of Coumarin derivatives has been the aim of many researchers. Based on these findings, a series of Coumarin substituted benzothiazoles were synthesized by refluxing Coumarin-4-carboxaldehyde and oaminothiophenol in acetic acid. Compounds were characterized by IR, 1H NMR and mass spectroscopy. All the compounds were tested for the...

2016
GABRIELA TATARINGA CATALINA STAN CORNELIA MIRCEA ALEXANDRA JITAREANU ANA-MARIA ZBANCIOC

The present study evaluated the antioxidant potential of 28 coumarin derivatives, using three antioxidant assays: DPPH inhibition, total reducing power and NO inhibition. Out of the tested compounds, the most active DPPH free radicals scavengers were the coumarin hydrazide derivatives. These substances were also the only ones among the investigated derivatives that exhibited a moderate reducing...

2014
J. Thipperudrappa

The effect of three aromatic amines namely aniline (AN), dimethyl aniline (DMAN) and diethyl aniline (DEAN) on emission properties of a coumarin derivative 6-methyl-3azidoacetyl coumarin (6M3AAC) in acetonitrile was studied by means of steady state fluorescence spectroscopy. The quenching of fluorescence intensity was observed in the presence of amines. The quenching process was characterized b...

Journal: :Molecules 2005
Irina O Zhuravel Sergiy M Kovalenko Sergiy V Vlasov Valentin P Chernykh

The parallel solution-phase synthesis of a new combinatorial library of 3-[4-(R1-coumarin-3-yl)-1,3-thiazol-2-ylcarbamoyl]propanoic acid amides 9 has been developed. The synthesis involves two steps: 1) the synthesis of core building blocks - 3- [4-(coumarin-3-yl)-1,3-thiazol-2-ylcarbamoyl]propanoic acids, 6 - by the reaction of 3-(omega-bromacetyl)coumarins 1 with 3-amino(thioxo)methylcarbamoy...

Journal: :Organic letters 2006
Thoi D Nguyen Ken C-F Leung Monty Liong Cari D Pentecost J Fraser Stoddart Jeffrey I Zink

[Structure: see text] The versatility of supramolecular chemistry has been exploited in constructing nanovalves based on mesoporous silica MCM-41 and the mutual recognition between secondary dialkylammonium ions and dibenzo[24]crown-8 (DB24C8). Naphthalene-containing dialkylammonium threads were tethered to the MCM-41, followed by loading with coumarin 460 and capping with DB24C8. Controlled re...

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