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

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