RESUMEN
A simple and regioselectively controlled method for the preparation of both 1,4- and 1,6-regioisomers of 1-substituted 4(6)-trifluoromethyl-pyrimidin-2(1H)-ones is described. Both regioisomers were synthesized from the cyclocondensation reaction of 4-substituted 1,1,1-trifluoro-4-methoxybut-3-en-2-ones: with nonsymmetric ureas for the 1-substituted 4-(trifluoromethyl)pyrimidin-2(1H)-ones (1,4-isomer) and with nonsymmetric 1-substituted 2-methylisothiourea sulfates for the synthesis of 1-substituted 6-(trifluoromethyl)pyrimidin-2(1H)-ones (1,6-isomer). Each method furnished only the respective isomer in very good yields. The structure of the products was assigned based on the (1)H and (13)C NMR as well as 2D HMBC spectral analysis.
RESUMEN
A new series of 3,6-disubstituted 2-(methylthio)-4-(trifluoromethyl)-3,4-dihydropyrimidin-4-ols displaying methyl, phenyl, aryl, and heteroaryl groups at the 6-position; and methyl, ethyl, allyl, and phenyl groups at the 3-position of the dihydropyrimidine ring, were synthesized and evaluated in vitro for acetylcholinesterase inhibitory activity. Seven compounds showed activity with IC50 values in the lower micromolar range. The compound 4-trifluoromethyl-6-(4-fluorophenyl)-3-methyl-2-methylthio-3,4-dihydropyrimidin-4-ol (6e) had the best inhibitory activity (IC50 2.2 ± 0.9 µm) and this inhibition was characterized as competitive. The molecular docking study showed that the acetylcholinesterase enzyme accommodates compound 6e in its catalytic site. The enantiomers of compound 6e, present similar interactions: π-π stacking interactions between the aromatic ring of the ligand's 4-fluorophenyl moiety and the aromatic rings of the electron-rich Trp84; and H-bonds between the hydroxyl group of Tyr121 and the hydroxyl moiety from 6e. The antioxidant effect of the dihydropyrimidin-4-ols was also investigated.
Asunto(s)
Acetilcolinesterasa/química , Inhibidores de la Colinesterasa/síntesis química , Pirimidinas/química , Acetilcolinesterasa/metabolismo , Animales , Antioxidantes/química , Sitios de Unión , Butirilcolinesterasa/química , Butirilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/metabolismo , Dípteros/enzimología , Diseño de Fármacos , Humanos , Concentración 50 Inhibidora , Simulación del Acoplamiento Molecular , Estructura Terciaria de Proteína , Pirimidinas/metabolismo , EstereoisomerismoRESUMEN
The synthesis and characterization of a new series of furan-3-carboxamides, from the aromatization of 4-trichloroacetyl-2,3-dihydrofuran to 3-trichloroacetyl furan followed by nucleophilic displacement of the trichloromethyl group or the corresponding carboxylic acid chloride by nitrogen-containing compounds, is presented. Preliminary in vitro antimicrobial activity of the title compounds was assessed against a panel of microorganisms including yeast, filamentous fungi, bacteria, and alga. Some of the furan-3-carboxamides exhibited significant in vitro antimicrobial activity. QSAR investigation was applied to find a correlation between the different physicochemical parameters of the compounds studied and their biological activity.