Coenzyme A esters of all-trans- and 13-cis-retinoic acid were synthesized for use in studying vitamin A metabolism. The esters were obtained by two different synthetic methods starting from retinoic acids, which were converted to activated succinimidyl esters or anhydrides. These in turn were coupled with coenzyme A to form their respective thioesters. The retinoyl coenzyme A esters were purifi...

Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS) in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides) producing a product with intense fluorescence, which was measured at 496 nm after ex...

“Maghnite” a montmorillonite sheet silicate clay, exchanged with protons to produce “H-Maghnite” is an efficient catalyst for polymerization of many vinylic and heterocyclic monomers (Belbachir, M. U.S. Patent. 066969.0101 –2001). The structure compositions of both “Maghnite” and “H-Maghnite” have been developed. This catalyst was used for the polycondensation of the tetrahydrofuran with phthal...

Acylation of anisole with 2-phenylbutanoic acid derivatives, over zeolite catalysts, gives the corresponding 4-acyl derivatives with high regioselectivity. In an analogous way, 2,3-dihydrobenzofuran reacts with acid anhydrides or chlorides in the presence of catalytic quantities of zeolites to give the corresponding 5-acyl-2,3-dihydrobenzofurans. The zeolite can be recovered, regenerated and us...

2-Aminoethylarsonic acid was tested for its ability to act as a substrate for ethanolamine-phosphate cytidylytransferase as a cytidylyl acceptor in place of ethanolamine phosphate. The expected product, like all mixed anhydrides of arsonic acids, should hydrolyse spontaneously with regeneration of the substrate analogue and CMP formation; such CMP production was observed. The limiting velocity ...

C-13-alkylated methoxy-8tf-dibenzo[a,g]quinolizin-8-ones 2a-e were synthesized by photocyclization of 1 -alkylidene-N-benzoyl-1,2,3,4-tetrahydroisoquinolines 1. Moreover, condensation of l,2,3,4-tetrahydro-6,7-dimethoxy-l-oxo-isoquinoline with homophthalic acid anhydrides 7a and b leads to the C-13-alkylated 8-oxoberbines 2b and c and improves the yields compared with those of the photocyclizat...

Carboxylic acid derivatives are the most widely occurring of all molecules, both in laboratory chemistry and in biological pathways. Specifically, acid derivatives are compounds in which the hydroxyl group of the carboxylic acid has been replaced by another acyl substituent that can act as a leaving group in nucleophilic acyl substitutions. These compounds can be acid halides, acid anhydrides, ...