Antioxidant capacity and environmentally friendly synthesis of dihydropyrimidin-(2H)-ones promoted by naturally occurring organic acids

The Biginelli reaction is a multicomponent reaction involving the condensation between an aldehyde, a beta-ketoester, and urea or thiourea, in the presence of an acid catalyst, producing dihydropyrimidinones (DHPMs). Owing to their important pharmacological properties, the DHPMs have been studied by many authors. However, most of the methodologies used for the synthesis of these compounds require drastic reaction conditions. In the current study, we report an efficient and clean procedure for preparing DHPMs by the use of citric acid or tartaric acid as a promoter of the Biginelli synthesis in ethanol as solvent. In addition, we have evaluated the antioxidant capacity of the compounds synthesized by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay and the thiobarbituric acid-reactive species test. Two compounds presented antioxidant activity and also reduced lipid peroxidation at concentrations of 200 and 300 mu M. In summary, we report an environmentally friendly procedure for the preparation of DHPMs and demonstrate the antioxidant capacity of some of the compounds. (C) 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:155161, 2012; View this article online at . DOI 10.1002/jbt.20424

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)

Centro de Capacitacao e Pesquisa em Meio Ambiente-Universidade de Sao Paulo (CEPEMA-USP)

Centro de Capacitacao e Pesquisa em Meio AmbienteUniversidade de Sao Paulo (CEPEMAUSP)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS)

Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS)

Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)