نتایج جستجو برای: prenyloxy coumarin

تعداد نتایج: 3805  

2009
Lassaad Mechi Samar Chtiba Naceur Hamdi Rached Ben Hassen

A new chalcone of the coumarin, C(21)H(18)O(7), containing an annulated α-pyrone ring, was obtained by condensation of the borate complex of ac-yl(hydr-oxy)coumarin with trimethoxy-benzaldehyde. The structure exhibits intra-molecular hydrogen bonding between the hydroxyl oxygen and the ketonic oxygen in the coumarin group. The bicyclic coumarin fragment and the benzene ring form a dihedral angl...

Mona Hosseini-Sarvari, Sepideh Najafvand-Derikvandi

Nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(Trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. Factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  This nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. The prepared sulfated titania s...

Journal: :Contact dermatitis 2007
Marc Vocanson Magalie Valeyrie Aurore Rozières Anca Hennino François Floc'h Arielle Gard Jean-François Nicolas

BACKGROUND There is controversy as to whether coumarin, an ingredient in cosmetics and fragrances, is a contact allergen involved in fragrance allergy. We recently showed that the purity of coumarin is a critical parameter for its allergenicity because coumarin preparations containing trace amounts of contaminants induced cell proliferation in the local lymph node (LN) assay whereas pure coumar...

2017
Ruey-Chorng Lin Mohamed Gamal Mohamed Tao Chen Shiao-Wei Kuo

In this study, we synthesized a novel multifunctional benzoxazine monomer (Coumarin-COOH BZ), possessing both coumarin and COOH groups, through the reaction of 4-methyl-7-hydroxycoumarin, 4-aminobenzoic acid, and paraformaldehyde in 1,4-dioxane, with the structure confirmed using 1H and 13C nuclear magnetic resonance and Fourier transform infrared (FTIR) spectroscopy. Differential scanning calo...

Journal: :Hematology. American Society of Hematology. Education Program 2006
Brian F Gage

To reduce the risk of hemorrhage, experts advocate prescribing the anticipated therapeutic dose to patients who are beginning coumarin therapy, but until now there was no accurate way to estimate that dose. Using pharmacogenetics-based coumarin therapy, clinicians can now estimate the therapeutic dose by genotyping their patients for single nucleotide polymorphisms (SNPs) that affect coumarin m...

Journal: :Molecules 2010
Pavol Hrdlovic Jana Donovalova Henrieta Stankovicova Anton Gaplovsky

Absorption and fluorescence spectra of bichromophoric coumarins were investigated in different solvents and in polymer matrices. These bichromophoric coumarins were composed of a coumarin dimethylamino-substituted at position 7 or unsubstituted coumarin and phthalimide or a 1,8-naphthylimide linked with an iminomethyl bridge to the position 3 or 8 of the coumarin ring. Absorption spectra of 7-d...

2017

Coumarin possesses a number of biological activities like antimicrobial, anti-inflammatory, analgesic, antioxidant, anticancer, antimalarial etc. Coumarin belongs to a group of benzpyranes, which consist of a benzene ring joined to a pyran nucleus. In the present study amino derivatives bearing coumarin nucleus are synthesized from 7-hydroxy -4methyl coumarin by using mild catalyst, CAN which i...

Journal: :Genetics 1983
D P Kasbekar S Madigan E R Katz

Nystatin-resistant mutations exhibit extreme sensitivity to 1.3 mm coumarin. The mutations fall into three complementation groups so it is possible to select for nonallelic mutations conferring sensitivity to coumarin by selection on nystatin-containing nutrient agar plates. Complementation between such coumarin-sensitive mutations allows the selection of diploids on coumarin-containing nutrien...

Journal: :Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete 1971
A Zheleva L Bubeva-Ivanova S L Spassov

Three new natural coumarin substances 1, 2 and 3 (derivatives of 2',2'-dimethyl-3',4'-dihydroxydihydropyrano-5',6':6,7-coumarin) were isolated from the roots and fruits of Peucedanum arenarium W.K. On the basis of the spectral data from UV, IR, and NMR spectra of coumarin 1, named peuarenarine, it was assumed, that, it is an ester of 2',2'-dimethyl-3',4'-dihydroxy-dihydropyrano5',6' :6,7-coumar...

Journal: :Dalton Transactions 2021

Pentacoordinated iridium( i )-cyclooctadiene complexes featuring a coumarin-functionalised imidazoline– or benzimidazoline–NHC ligand exhibit fluxional behavior as consequence of the hemilability pyrone ring in coumarin wingtip.

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