4H-Pyran-4-one derivatives:

Abstract

A series of 3-hydroxy-6-methyl-2-((4-substitutedpiperazin-1-yl)methyl)-4H-pyran-4-on e structured compounds were synthesized by reacting 5-hydroxy-2-methyl-4H-pyran-4-one with suitable piperazine derivatives using Mannich reaction conditions. Antibacterial activities of the compounds for E. coli, S. paratyphi, S. flexneri, E. gergoviae, and M. smegmatis were assessed in vitro by using broth dilution for determination of the minimum inhibitory concentration (MIC). In addition, their inhibitory effects over DNA gyrase enzyme were evaluated using a DNA gyrase supercoiling assay. Among the synthesized compoundscompound 7 showed a 4 mu g/mL MIC value for M. smegmatis, whereas the other compounds demonstrated moderate to high activity. Those tested in the supercoiling assay had at best a very mild inhibition of the enzyme. This series deserves further attention for testing over Mycobacterium species and topoisomerase II inhibition to develop new lead drugs.