نتایج جستجو برای: coumarin content

تعداد نتایج: 418276  

Journal: :Molecules 2017
Marek Cigáň Miroslav Horváth Juraj Filo Klaudia Jakusová Jana Donovalová Vladimír Garaj Anton Gáplovský

The water sensing properties of two efficient two-component fluorescent "turn-on" chemo-sensors based on the 7-dialkylaminocoumarin oxime acid-base equilibrium were investigated. Interestingly, although simple frontier orbital analysis predicts an intramolecular photoinduced electron transfer quenching pathway in conjugated oximates, TD-DFT (Time-dependent density functional theory) quantum che...

Journal: :Polish Journal of Chemical Technology 2021

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-...

2013
Sukriti Nigam

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...

2013
Saleta Vazquez-Rodriguez Eugenio Uriarte Lourdes Santana

In the title coumarin derivative (also known as 2H-chromen-2-one or 2H-1-benzopyran-2-one), C17H11NO6, the coumarin ring system is nearly planar, with a dihedral angle of 3.35 (9)° between the pyrone and the benzene rings. The dihedral angle between the planes formed by the coumarin ring system and the benzene substituent is 54.60 (7)°, clearly showing the non-coplanarity of the whole aromatic ...

2012
Monika Johansson Jana Tomankova Shengjie Li Galia Zamaratskaia

The aim of this study was to develop a robust method for the simultaneous determination of the activities of three porcine CYP450 enzymes in hepatic microsomes. A cocktail consisting of three selective CYP450 probe substrates, 7-ethoxyresorufin (CYP1A), coumarin (CYP2A) and 7-benzyloxy-4-trifluoromethylcoumarin (BFC; CYP3A), was incubated with porcine liver microsomes. The presence of 7-ethoxyr...

2009
Hoong-Kun Fun Samuel Robinson Jebas Mehtab Parveen Zakia Khanam Raza Murad Ghalib

In the crystal structure, the title compound, C(24)H(22)O(8), lies on a twofold rotation axis and the asymmetric unit comprises one half-mol-ecule. The dihedral angle formed by the coumarin unit with the symmetry-related part is 74.78 (14)°. One of the meth-oxy groups attached to the coumarin unit is considerably twisted, making an angle of 87.17 (17)° with respect to the coumarin unit; the oth...

Journal: :Molecules 2007
Shih-Lun Lin Pei-Yu Kuo Ding-Yah Yang

This paper describes the fine-tuning of the acidichromic properties of a coumarin-containing colorant 1 by incorporation of electron-donating and electron-withdrawing substituents on the coumarin moiety. Colorant 1 can undergo two distinct and reversible color changes under both strongly acidic and basic conditions, but not in the presence of gaseous ammonia. The results indicated that the brom...

2004
Wei Fu Dinesh Shenoy Jane Li Curtis Crasto Graham Jones Charles Dimarzio Srinivas Sridhar Mansoor Amiji

To increase the targeting potential, circulation time, and the flexibility of surface-attached biomedically-relevant ligands on gold nanoparticles, hetero-bifunctional poly(ethylene glycol) (PEG, MW 1,500) was synthesized having a thiol group on one terminus and a reactive functional group on the other. Coumarin, a model fluorescent dye, was conjugated to the PEG spacer and gold nanoparticles w...

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...

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