Synthesis of 2-aminopyridine lactones and study of their antioxidant, antibacterial and antifungal properties.

In the present work, the synthesis and biological activity of substituted 2-aminopyridine δ-lactones derivatives were achieved. 4,6,6-trimethyl-2-oxo-5,6-dihydro-2H-pyran-3-carbonitrile was synthetised from 4-hydroxy-4-methylpentan-2-one and then its enaminonitrile was obtained with DMFDMA. This enaminonitrile with amines gave substituted 2-aminopyridine δ-lactones identified by various spectroscopic methods (IR, ¹H NMR, ¹³C NMR and MS). The antioxidant effects of substituted 2-aminopyridine δ-lactones derivatives were evaluted through DPPH assay and revealed a great antioxydant capacity.The antifungal and antibacterial activities were tested by disc diffusion method against clinical Gram-negative bacteria and against clinical fungi. The study shows moderate to very good antibacterial and antifungal activities for the new substituted 2-aminopyridine δ-lactones derivatives.