نتایج جستجو برای: coumarin

تعداد نتایج: 3800  

Journal: :Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2015
Liang Han Rui Kang Xiaoyan Zu Yanhong Cui Jianrong Gao

2-(Thiophen-2-yl)thiazole was introduced as a π-bridge into diethylamino coumarin and novel coumarin sensitizers were synthesized with cyanoacrylic acid or rhodanine acetic acid as electron acceptor. Their light-harvesting capabilities and photovoltaic performance were investigated and compared with those of a similar sensitizer bearing a phenylthiophene bridge. Replacement of benzene in the π-...

Journal: :Organic & biomolecular chemistry 2015
Ha H Pham Christopher Szent-Gyorgyi Wendy L Brotherton Brigitte F Schmidt Kimberly J Zanotti Alan S Waggoner Bruce A Armitage

Dye-protein fluoromodules consist of fluorogenic dyes and single chain antibody fragments that form brightly fluorescent noncovalent complexes. This report describes two new bichromophoric dyes that extend the range of wavelengths of excitation or emission of existing fluoromodules. In one case, a fluorogenic thiazole orange (TO) was attached to an energy acceptor dye, Cy5. Upon binding to a pr...

2009
Cui-Lian Xu Nan Yang Guo-Yu Yang Su-Fang Fan Cao-Yuan Niu

The title compound, C(19)H(14)O(4), was prepared by the reaction of 2-oxo-2H-chromene-3-acyl chloride with cinnamic alcohol. The whole mol-ecule is not planar, the dihedral angle between the planes of coumarin and benzene rings being 13.94 (4)°, but the plane of the coumarin ring and that of the ester group are almost coplanar, making a dihedral angle of 2.9 (1)°. In the crystal structure, weak...

2015
Audray Dugrand-Judek Alexandre Olry Alain Hehn Gilles Costantino Patrick Ollitrault Yann Froelicher Frédéric Bourgaud Chunxian Chen

Citrus plants are able to produce defense compounds such as coumarins and furanocoumarins to cope with herbivorous insects and pathogens. In humans, these chemical compounds are strong photosensitizers and can interact with medications, leading to the "grapefruit juice effect". Removing coumarins and furanocoumarins from food and cosmetics imply additional costs and might alter product quality....

2014
Adi Basukriadi Richard M. Wilkins

An extract of a rotenone-containing plant yam bean, Pachyrhizus erosus (L.) Urban, seeds was tested against the diamondback moth, Plutella xylostella (L.) in a greenhouse to determine its potential as an oviposition deterrent and compared with coumarin and rutin, known as diamondback moth oviposition deterrent compounds, rotenone, and an extract of Peruvian cube root, at a concentration of 0.5%...

2011
Stefanie Kellner Salifu Seidu-Larry Jürgen Burhenne Yuri Motorin Mark Helm

A multifunctional reagent based on a coumarin scaffold was developed for derivatization of naive RNA. The alkylating agent N3BC [7-azido-4-(bromomethyl)coumarin], obtained by Pechmann condensation, is selective for uridine. N3BC and its RNA conjugates are pre-fluorophores which permits controlled modular and stepwise RNA derivatization. The success of RNA alkylation by N3BC can be monitored by ...

Journal: :Molecules 2017
Letícia Paula Leonart João Cleverson Gasparetto Flávia Lada Degaut Pontes Letícia Bonancio Cerqueira Thais Martins Guimarães de Francisco Roberto Pontarolo

Coumarin (1,2-benzopyrone) is a natural compound whose metabolism in humans was established in the 1970s. However, a new metabolite was recently identified in human plasma, indicating that the metabolism of coumarin has not been completely elucidated. To complement the knowledge of its metabolism, a rapid and sensitive method using UPLC-QTOF-MS was developed. A total of 12 metabolites was ident...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1994
P Houston T Kodadek

A method is described for monitoring the enzyme-mediated unwinding of duplex DNA spectrophotometrically. The assay employs a partially duplex oligonucleotide substrate modified at the complementary end with coumarin and fluorescein moieties. When in close proximity the fluorescein quenches the fluorescence of coumarin. However, when the strands are separated by the action of a DNA helicase, the...

2015
Shashikanth Walki S. Naveen S. Kenchanna K. M. Mahadevan M. N. Kumara N. K. Lokanath

In the title compound, C17H13NO5, the coumarin ring system is essentially planar (r.m.s. deviation = 0.008 Å). The nitro-phenyl ring makes a dihedral angle of 25.27 (9)° with the coumarin ring plane. The nitro group is almost coplanar with the phenyl ring to which it is attached, making a dihedral angle of 4.3 (3)°. The eth-oxy group is inclined to the coumarin ring plane by 4.1 (2)°. Electron ...

Journal: :Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy 2012
Chiranjib Ghatak Vishal Govind Rao Sarthak Mandal Rajib Pramanik Souravi Sarkar Pramod K Verma Nilmoni Sarkar

In this article we have studied Förster Resonance Energy Transfer (FRET) using 2-aminopurine (2-AP), a structural isomer of adenine as donor and various Coumarins as acceptors inside AROSOL-OT (AOT)-water reverse micelles (RM) using steady-state and time-resolved fluorescence spectroscopies. We have used three sets of FRET and all the pairs except 2-AP-Coumarin-480 exhibited quite efficient FRE...

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