Microporenic Acids A–G, Biofilm Inhibitors, and Antimicrobial Agents from the Basidiomycete <i>Microporus</i> Species

The need for effective compounds to combat antimicrobial resistance and biofilms which play important roles in human infections continues to pose a major health challenge. Seven previously undescribed acyclic diterpenes linked to isocitric acid by an ether linkage, microporenic acids A–G (<b>1</b>–<b>7</b>), were isolated from the cultures of a hitherto undescribed species of the genus <i>Microporus</i> (Polyporales, Basidiomycota) originating from Kenya’s Kakamega forest. Microporenic acids D and E (<b>4</b> and <b>5</b>) showed antimicrobial activity against a panel of Gram positive bacteria and a yeast, <i>Candida tenuis</i>. Moreover, microporenic acids A and B (<b>1</b> and <b>2</b>) demonstrated dose-dependent inhibition of biofilm formation by <i>Staphylococcus aureus</i>. Compound <b>1</b> further showed significant activity against <i>Candida albicans</i> and <i>Staphylococcus aureus</i> preformed biofilms