A series of bisoumarin (1-4) and dihydropyran (5-8) derivatives were successfully synthesized as new antibacterial agents. The molecular structures of three representative compounds 1, 5 and 7 were confirmed by single crystal X-ray diffraction study. Among these compounds tested toward Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), and USA 300 (Los Angeles County clone, LAC), compounds 1 and 2 displayed the most potent antibacterial activity. Additionally, the HB energy in biscoumarins 1-4 was calculated by density functional theory (DFT) [B3LYP/6-31G*] method.
Keywords: Antibacterial; Bisoumarin; DFT; Dihydropyran.