Abstract:
Three new alkyl substituted anthraquinone derivatives, trivially named as symploquinones
A-C (Compounds 1-3) were isolated from
Symplocos racemosa. The structures of these compounds were determined on the basis of extensive spectroscopic analyses (UV, IR, Mass,
1H-and
13C-NMR, and two-dimensional (2D) NMR techniques). The resulting data were also compared with the reported literature. These compounds were then subjected to antibacterial or antibiofilm testing. Compounds
1 and
3 exhibited good antibacterial activity in the concentration range of 160-83 μg·mL
-1 against
Streptococcus mutans, methicillin resistant
Staphylococcus aureus and
Proteus mirabilis. Both compounds were further screened for anti-biofilm activity, which revealed promising activities at sub-MIC concentrations. None of the compounds were found to be active against
Klebsiella pneumoniae.