نتایج جستجو برای: sesquiterpene coumarin
تعداد نتایج: 6204 فیلتر نتایج به سال:
Objective During the last three decades sesquiterpenoid lactones have emerged as one of the largest groups of plant products with over 3000 naturally occurring substances known. The genus Artemisia characteristically contains this biologically active type of secondary metabolites. With respect to increasing interest in the cytotoxic, antibiotic, phototoxic and antineoplastic activities of sesq...
A series of lanthanide complexes [Ln(dpxCy)3](3-) have been synthesised. The ligands are composed of a coordinating dipicolinic acid backbone decorated with a polyoxyethylene arm fitted with a coumarin moiety at its extremity. The nature of the coumarin as well as the length of the linker have been varied. Upon excitation at 320 nm, the coumarin exclusively acts as an antenna while the dipicoli...
Wide individual variations in response to drugs is a common clinical problem, and is especially evident with coumarin anticoagulant therapy (1-3). A possible contributing factor to such variations could be the influence of another presumably unrelated drug upon the response to the coumarin anticoagulant. Reports from several laboratories (4-7) indicate that barbiturates can reduce the prothromb...
A series of new conjugated compounds with a -SCH₂- linkage were synthesized by chemical methods from imidazole and coumarin derivatives. The experimental results indicate that of the twenty newly synthesized imidazole-coumarin conjugates, three of them exhibited appealing EC50 values (5.1-8.4 μM) and selective indices >20 against hepatitis C virus. Their potency and selectivity were increased s...
Absract: Rotational dynamics of two structurally similar coumarins; coumarin 7 and coumarin 30 has been studied using a steady state fluorescence depolarization technique and time correlated single photon counting method as a function of temperature in ethanol and n-decane solvents. Experimentally measured reorientation times of these coumarins are identical in a given solvents at a particular ...
Microwave-assisted synthesis and antioxidant properties of hydrazinyl thiazolyl coumarin derivatives
UNLABELLED BACKGROUND Coumarin derivatives exhibit a wide range of biological properties including promising antioxidant activity. Furthermore, microwave-assisted organic synthesis has delivered rapid routes to N- and O-containing heterocycles, including coumarins and thiazoles. Combining these features, the use of microwave-assisted processes will provide rapid access to a targeted coumarin...
Coumarin meets fluorescein: a Förster resonance energy transfer enhanced optical ammonia gas sensor.
This study focuses on the development of an optical ammonia gas sensor, the sensing mechanism of which is based on Förster resonance energy transfer (FRET) between coumarin and fluorescein. The dyes were immobilized into an organically modified silicate matrix during polymerizing methyltriethoxysilane with trifluoropropyltrimethoxysilane on a poly(methyl methacrylate) substrate. The resulting d...
an efficient synthesis of some novel coumarin derivatives via 1, 4- michael addition of indole to coumarin chalcones catalyzed by cellulose sulphonic acid (csa) under solvent free conditions is described. the corresponding michael addition products were obtained in good to excellent yield. the synthesized compounds were screened for their antibacterial activity against e. coli, s. aureus and an...
Sesquiterpene lactones display a wide variety of biological effects such as antiviral, anti-inflammatory and cytotoxic activity. In previous studies some derivatives of sesquiterpene lactones were prepared to be tested as antiviral and/or cytoxic agents. In the present report we describe the effects of seven modified sesquiterpene lactones on the proliferation of several cancer cell lines. We d...
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