Encontrados 24 documentos, a visualizar página 1 de 3

Microwave synthesis of novel water-soluble 2-, 5- and 9-substituted benzo[a]phe...

Microwave irradiation was used for the first time in an efficient synthesis of benzo[a]phenoxazinium chlorides. The main advantage of this protocol is the notable reduction in reaction times and good to excellent yields of the products were achieved in comparison with classical heating conditions as described. These new series of compounds possess 5-amine and/or 2-hydroxyl substituents in the polycyclic system ...

Acridinyl methyl esters as photoactive precursors in the release of neurotransm...

An investigation of the use of an azaheterocycle, acridine, as an alternative photochemically removable protecting group for the carboxylic function of neurotransmitter amino acids was carried out. 9-Bromomethylacridine was used in the reaction with glycine, alanine, glutamic acid, β-alanine and γ-aminobutyric acid, to obtain model ester derivatives, which were irradiated at different wavelengths in a photochem...

Antifungal photodynamic efficacy of Benzo[a]phenoxazinium chlorides against Can...

Photorelease of amino acids from novel thioxobenzo[f]benzopyran ester conjugates

Aiming at the enhancement of the performance of (9-methoxy-3-oxo-3H-benzo[f]benzopyran-1-yl) methyl ester as photocleavable protecting group for the carboxylic acid function at long-wavelengths, 9-methoxy-3-thioxo-3H-benzo[f]benzopyran-L-valine and L-phenylalanine model conjugates were prepared through a thionation reaction of the corresponding oxo-benzobenzopyrans. These thioxobenzobenzopyran derivatives were ...

Synthesis of 4-amino-3,5-dicyano-arylpyrazoles : part 2 : isolation and charact...

Reaction of (dicyanomethylidene-hydrazino)benzoic acids with chloroacetonitrile, under basic conditions, gave cyanomethyl-3-(7-amino-3,5-dicyano-1H-pyrazolo[4,3-d]pyrimidin-1-yl-benzoates and para substituted cyanomethyl benzoates, in addition to the expected cyanomethyl 3-(4-amino-3,5-dicyano-1H-pyrazol-1-yl)-benzoates.

Bifunctionalised long-wavelength fluorescent probes for biological applications

The synthesis of benzo[a]phenoxazinium chlorides which are bifunctionalised in position 2 with 4-ethoxy-4-oxobutoxyl, 3-hydroxypropoxyl or 3-chloropropoxyl groups, and in position 9 with the (aminopropyl)amino group, was efficiently performed. The covalent labeling of valine was carried out by using one of the new fluorophores obtained. Photophysical studies in the homogeneous media of ethanol, distilled water...

DNA fluorescence probes based on side-chain chlorinated benzo[a]phenoxazinium c...

Several side chain chlorinated benzo[a]phenoxazinium chlorides functionalized with various types of terminals at the 5- and 9-amino positions of the heteroaromatic ring were used in photophysical studies with DNA. It was found that the functionalised terminal has a dramatic influence on the type of interaction with the amino group at the 9-amino position greatly promoting intercalation.

Novel DNA fluorescence probes based on N-[5-(11-functionalised-undecylamino)-9H...

Fluorescent benzo[a]phenoxazinium chlorides possessing undecylamino chains with functionalised ending-groups (hydroxyl, carboxylic acid and the ester group) as substituents at the 5-position of the heterocycles were successfully synthesised and characterised. These compounds were used in photophysical studies with DNA, and compared to the corresponding analogue with a non-functionalised terminal (methyl group)....

N-(Di)icosyl-substituted benzo[a]phenoxazinium chlorides : synthesis and evalua...

Five benzo[a]phenoxazinium chlorides containing alkyl chains with twenty carbon atoms on 5- or 9-positions of the tetracyclic ring were efficiently synthesised and characterised by UV/Vis/NIR spectroscopy. The absorption and emission maxima in ethanol lie in the range 627-641 nm and 645-676 nm, respectively, with quantum yields varying from 0.14 to 0.38. Preliminary photophysical studies with these fluorochromo...

Phototriggering of neuroactive amino acids from 5,6-benzocoumarinyl conjugates

Uncaging of several neuroactive amino acids, namely β-alanine, tyrosine, 3,4-dihydroxyphenylalanine (DOPA) and glutamic acid from the corresponding 5,6-benzocoumarinyl conjugates was carried out by irradiation at different wavelengths and in different solvent systems. The release of the various amino acids was faster in ACN/HEPES buffer mixtures and for the tyrosine conjugate, an increase in the photolysis reac...