A new polyprenylated benzophenone, named epunctanone (1), was isolated from the stem bark of Garcinia epunctata Stapf, together with eight known compounds, 7-epiisogarcinol (2), 2,6-dimethoxy-p-benzoquinone (3), friedelin (4), lupeol (5), 16β-hydroxylupeol (6), betulin (7), stigmasterol (8), and rheediaxanthone A (9). The structure of epunctanone (1) was established by detailed analysis of its spectroscopic data, especially 1D- and 2D-NMR, and HR-MS data. All these compounds were evaluated for their antimicrobial and anti-protozoan activities. They were also assayed to determine if any of the compounds were nonpeptide agonist ligands for nematodal G-protein-coupled receptors, which would be an indication of potential antinematodal activity. Among the isolated compounds, 7-epiisogarcinol (2) was the most active against Candida albicans.