title: Antioxidant capacity and environmentally friendly synthesis of dihydropyrimidin-(2H)-ones promoted by naturally occurring organic acids.
abstract: The Biginelli reaction is a multicomponent reaction involving the condensation between an aldehyde, a β-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 µM. In summary, we report an environmentally friendly procedure for the preparation of DHPMs and demonstrate the antioxidant capacity of some of the compounds.
authors.affiliation: Universidade Federal de Pelotas, Centro de Ciências Químicas, Farmacêuticas e Alimentos, Campus Universitário s/n, 96010-900, Capão do Leão, RS, Brazil.
authors.forename: Alana
authors.initials: A
authors.lastname: de Vasconcelos
authors.forename: Pathise S
authors.initials: PS
authors.lastname: Oliveira
authors.forename: Marina
authors.initials: M
authors.lastname: Ritter
authors.forename: Rogério A
authors.initials: RA
authors.lastname: Freitag
authors.forename: Renato L
authors.initials: RL
authors.lastname: Romano
authors.forename: Frank H
authors.initials: FH
authors.lastname: Quina
authors.forename: Lucas
authors.initials: L
authors.lastname: Pizzuti
authors.forename: Claudio M P
authors.initials: CM
authors.lastname: Pereira
authors.forename: Francieli M
authors.initials: FM
authors.lastname: Stefanello
authors.forename: Alethéa G
authors.initials: AG
authors.lastname: Barschak
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D019343:Citric Acid / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D011744:Pyrimidinones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents / Q000737:chemistry; D013644:Tartrates / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D011744:Pyrimidinones; D012997:Solvents; D013644:Tartrates; D019343:Citric Acid; D000431:Ethanol; C029768:tartaric acid