Ajmal Bhat - Department of Natural Science, S.B.B.S.University, Jalandhar Punjab-۱۴۴۰۳۰ (India)

Annulated pyrano[2,3-d]pyrimidine/pyrano[2,3-d]uracil derivatives were synthesized using aromatic aldehydes, active methylene compounds and barbituric acid in presence of dibutylamine (DBA) catalyst in ethanol as solvent. The different substituents on phenyl ring in the fused pyrano uracil skeleton showed productive influence on its antimicrobial activity against some gram positive and gram negative bacteria like Pseudomonas aureus, E. coli, Staphylococcus aureus, Klebsiella pneumonia and Bacillus cereus. Antibacterial screening revealed that the presence of heteroaryl, cyano and amino groups on uracil skeleton increases its penetrating power on bacterial cell wall and product becomes more biologically energetic. The antimicrobial activity results showed some definite and interesting facts about the structure activity relationship (SAR) of synthesized molecules.

Annulated uracils, structural dependent biological activity, gram positive, gram negative bacteria, pharmacophore sites