Dentifragilones A–B and Other Benzoic Acid Derivatives from the European Basidiomycete Dentipellis fragilis

Abstract

A chemical and biological exploration of the European polypore <i>Dentipellis fragilis</i> afforded two previously undescribed natural products (<b>1</b> and <b>2</b>), together with three known derivatives (<b>3</b>-<b>5</b>). Chemical structures of the isolated compounds were confirmed through 1D/2D NMR spectroscopic analyses, mass spectrometry, and by comparison with the reported literature. The relative and absolute configurations of <b>1</b> were determined according to the ROESY spectrum and time-dependent density functional theory electronic circular dichroism (TDDFT-ECD), respectively. Furthermore, the absolute configuration of dentipellinol (<b>3</b>) was revisited and revealed to be of (<i>R</i>) configuration. All the isolated compounds were assessed for their cytotoxic and antimicrobial activities, with some being revealed to have weak to moderate antimicrobial activity, particularly against Gram-positive bacteria.