Umar Farooq , 1 , Sara Khan 1 , Sadia Naz 1 , Ajmal Khan , 1 , Afsar Khan , 1 , Ayaz Ahmed 2 , Abdur Rauf 3 , Syed Majid Bukhari 1 , Shujaat Ali Khan 4 , Arfa Kamil 5 , Nadia Riaz 6 , Abdur Rahman Khan 1
20 December 2017
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.