نتایج جستجو برای: bis coumarin
تعداد نتایج: 51675 فیلتر نتایج به سال:
Coumarin, the parent compound of warfarin, has been observed to stimulate macrophages, increase phagocytosis, and induce changes in lymphocyte-mitogen responsiveness in cancer patients. Coumarin has been reported to have antitumor activity in human melanomas and renal cancer when used in conjunction with the H-2 antagonist, cimetidine. We have observed that coumarin has antiprostatic activity i...
The main structural unit of the title compoud, C(21)H(18)O(6), is a fused three-ring group consisting of coumarin and tetra-hydro-pyrane ring systems. Two C atoms of the tetra-hydro-pyran ring are displaced by 0.295 (3) and -0.360 (2) Å from the mean plane of coumarin ring. The dihedral angle between the phenyl and coumarin rings is 73.94 (3)°. Inter-molecular O-H⋯O hydrogen bonds are present i...
the synthesis of functionalized 2-oxo-2h-coumarin derivatives has been studied by a one-pot reaction of o-hydroxybenzaldehyde, ethyl 2-bromoacetate and triphenylphosphine in the presence of catalytic amount of triethyl amine in etoac, water or under solvent free conditions. we have found the best results obtained under solvent free condition.
Previous investigations have shown that CY4-labeled transcinnamic acid is rapidly converted to o-coumaric acid P-glucoside by shoots of Melilotus alba (white sweet clover) (1) and Hierochlod odorata (sweet grass) (2). This glucoside is then converted to coumarin (l-3), possibly by way of trans-cis isomerization of the glucoside to coumarinic acid P-glucoside. The small amount of radioactivity f...
ABSTRACT. Among oxygen-containing heterocyclic compounds such as coumarin and azacoumarin derivatives, the scaffold has become an important construction motif for developing new drugs. Coumarin its derivatives possess many types of biological activities have been reported to show significant cytotoxic activity. N-(6,8-disubstituted coumarin-3-yl)benzamides (8a-c) namely (3-N-(benzoyl) aminocoum...
N sweetclover (Melilotus alba Desr.) the allelic pair designated B/b was I originally thought to be concerned with coumarin biosynthesis. Extracts of BB plants were reported to contain substantial amounts of both free and bound coumarin, while extracts of bb plants contained only bound coumarin (GOPLEN. GREENSHIELDS and BAENZIGER 1957; HASKINS and GORZ 1957), more recently identified as coumari...
A novel coumarin-centered amphiphilic star-block polymer of C-(PDMAEMA(80)-b-PS(8))(3) has been designed to investigate the pH-induced accompanying outward movement of hydrophobic coumarin centers within the polymer micelles upon protonation.
Coumarin analogues were synthezised and evaluated as acceptors for the intrinsic fluorescence resonance energy transfer (iFRET) of tryptophan residues in target proteins. The fluorescence properties such as quantum yields, iFRET efficiencies, and Förster distances of the prepared coumarin analogs were determined in a model system, by their conjugation to biotin, utilizing streptavidin (SAV) as ...
In the title coumarin derivative, C28H26N2O2, the coumarin unit is approximately planar, with a maximum deviation of 0.048 (3) Å. The central benzene ring is oriented at dihedral angles of 30.15 (14) and 10.51 (11)°, respectively, to the pyridine ring and coumarin ring system. In the crystal, weak C-H⋯O and C-H⋯N hydrogen bonds and weak C-H⋯π inter-actions link the mol-ecules into a three-dimen...
The synthesis of some fluorescent coumarin dyes derived from coumarin-3-carboxylic acid were described.The new dyes are obtained by condensation of coumarin – 3 carboxylic acid derivatives with para substituted ortho phenylenediamines and cyclisation of the mono condensed ortho phenylenediamines in an acid medium. The obtained dyes were characterized from their physico-chemical point of view by...
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