Acronyculatin S, a polyphenolic isoprenylated acetophenone benzofuran with antibacterial properties from the flowers of Acronychia pedunculata

Phytochemical investigation of the flowers of Acronychia pedunculata led to the isolation of eight compounds. They consist of one undescribed polyphenolic isoprenylated acetophenone benzofuran, acronyculatin S (1), and seven known compounds: demethylacrovestone (2), acrovestone (3), acroflavone A (4), 3,5,4'-trihydroxy-3',8-dimethoxy-7-(3-methylbut-2-enyloxy)flavone (5), xanthotoxin (6), isopimpinellin (7) and N-methylflindersine (8). The structures of the isolated compounds were elucidated by thorough analysis of spectroscopic (IR, NMR and ECD) and spectrometric (MS) data. Compounds 1 and 2 were tested against seven bacterial strains. They displayed significant activities against methicillin-resistant Staphylococcus aureus and Bacillus subtilis with MIC values in the range of 2-8 µg/mL.