نتایج جستجو برای: bis coumarin
تعداد نتایج: 51675 فیلتر نتایج به سال:
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...
Cress (Lepidium sativum) seeds were germinated in darkness. Seedlings were investigated for soluble proteins by SDS-PAGE. Two proteins were identified by microsequencing: the small subunit of ribulosebisphosphate carboxylase (SSU) and the alpha subunit of the storage protein cruciferin. Net synthesis of small and large subunits of ribulosebisphosphate carboxylase (SSU and LSU) was investigated ...
P . R o d i g h i e r o , A . G u i o t t o * , P . M a n z i n i , a n d G . P a s t o r i n i Ist ituto di Chimica Farmaceutica dell 'Universita di Padova , Centro di Studio della Chimica del Farmaco e dei Prodott i Bio logicamente attivi del C N R , V ia Marzolo 5, 1-35100 Padova , I taly Z. Naturforsch. 34b , 1010-1014 (1979); received February 19, 1979 Isoponcimarin, Isomeranzin, Dihydroor...
A coumarin-based prodrug system plays a significant role in preparing esterase-sensitive prodrugs of amines and peptides. The electronic structures of 27 coumarin-based prodrugs developed in our lab were calculated at a B3LYP/6-31+G (d,p) level with a Gaussian 03 program. The calculated structural parameters were taken as theoretical descriptors to establish five novel QSPR models. The SMLR lin...
The Coumarine heterocyclic ring is common feature of various bioactive compounds such as calanolides, lipid-lowering agents. The Chemists all over the globe are motivated not only for the environmentally benign synthesis of new products but also to develop green synthesis for existing chemicals. Coumarins, the most important classes of fluorescent molecules constitute important structural featu...
Abstract Coumarin and its nitrogen analogue 1-aza coumarin are a class of lactones lactams, respectively, which indispensable heterocyclic units to both chemists biochemists. 1-Aza derivatives, ultimately metabolize as the corresponding 8-hydroxy coumarins in biological system therefore found be very good anti-inflammatory, anti-cancer, analgesic agents. A series hybrid substituted azacoumarin-...
Microbial biotransformation, one of the tools of green chemistry, is widely used in organic synthesis to cutshort number of organic intermediates in obtaining the final required compounds. In the present study, an approach was made for preparing substituted derivatives of coumarin as therapeutic agents. Nine biotransformation experiments were performed where random combination of four microorga...
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