Lipophilic esters of hydroxytyrosol have been synthesized in a one-pot procedure from tyrosol and long side-chain carboxylic acids by lignin nanoparticles supported enzymatic cascade lipase M tyrosinase. The reaction involved the initial esterification aliphatic group with hydroxyl followed ortho-hydroxylation aromatic moiety. Lipase tyrosinase were immobilized on layer-by-layer using chitosan ...

Background: Padina sp. is an algae that has potential as a functional food. This study aimed to explore the chemical and photochemical constituent in the methanolic exract of Padina sp. Methods: Brown algae of Padina sp. from Puntondo coast, Takalar, Indonesia was prepared. The algae characterization was carried out based on the standard procedure of Association of Official Agricultural Chemis...

the imine intermediate generated by the addition of primary amine to the cinnamaldehyde is trapped by the n-isocyaniminotriphenylphosphorane (ph3pnnc) and a carboxylic acid, and leads to the formation of the corresponding iminophosphorane intermediate. the 1,3,4-oxadiazole derivatives are formed via intramolecular aza-wittig reaction of the iminophosphorane intermediate. the reactions were comp...

Infrared spectra of some deuterio analogues of carboxylic acids in heavy water have been investigated and their spectral behavior in carbonyl stretching frequency region have been interpreted in terms of their structural behavior in aqueous solutions. It has been shown that a linear relationship exists between carbonyl stretching frequency of solvated acids at infinite dilution and their...

This review examines the methods used to study carboxylic acids and the results of such studies on certain acids in freshwater snails. The three areas of carboxylic acid interest considered in this review involve their roles as metabolites, phagostimulants, and biomarkers. The chromatographic and non-chromatographic methods used to study the carboxylic acids in the snails are considered herein....

25 aromatic carboxylic acids which are analogs of benzoic acid were tested in the rat diaphragm preparation for effects on chloride conductance (G(Cl)). Of the 25, 19 were shown to reduce membrane G(Cl) with little effect on other membrane parameters, although their apparent K(i) varied widely. This inhibition was reversible if exposure times were not prolonged. The most effective analog studie...

The nitro group in aromatic nitro compounds containing reducible substituents such as methyl, carboxylic acids and phenols, and halogens are selectively and rapidly reduced at room temperature to the corresponding amines in good yield by employing hydrazine glyoxylate in the presence of zinc powder or magnesium powder. It has been observed that hydrazine glyoxylate is more effective than hydraz...