Antibacterial efficacy of pyranopyrimidinone derivatives synthesized using a facile one-pot reaction

Discovering new and effective medications against resistant bacteria is an urgent need to save modern medicine, as well as prevent and treat life-threatening diseases. This study aimed to synthesize a series of pyrano[2,3-d]pyrimidinone derivatives using a Tandem Knoevenagel-Michael cyclocondensation reaction. All the synthetic compounds were screened for antibacterial activity against various bacterial strains and isolates. Compound 7‐amino‐6‐cyano‐5-(5-nitrofuran-2-yl)‐pyrano[2,3-d]pyrimidin‐(1H,3H)-2,4‐diones (4s) showed superb antibacterial activities against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli with a minimum inhibitory concentration (MIC) ranging from 3.91 to 7.81 μg/mL. This compound also exhibited more potent antibacterial activity than levofloxacin against methicillin-resistant S. aureus (MRSA) with a MIC value of 3.91 μg/mL and demonstrated relatively no cytotoxicity at the mentioned MIC concentration. Field-emission scanning electron microscopy (FE-SEM) confirmed the complete damage of S. aureus and E. coli following exposure to compound 4s. The compound 4s has the potential to be used as an alternative antibacterial drug after supplementary studies.