| Summary: | Seven alkaloidal compounds (<b>2</b>–<b>8</b>) and one polyketide (<b>1</b>) were isolated from a semisolid rice culture of the marine-derived fungus <i>Aspergillus</i> sp. F452. Structures of the isolated compounds were elucidated based on spectroscopic data and comparisons with previously reported data. The alkaloidal compounds (<b>2</b>–<b>8</b>) displayed weak to moderate inhibitory activities against <i>Staphylococcus aureus</i>-derived sortase A (SrtA) without affecting cell viability. Aspermytin A (<b>1</b>) strongly inhibited SrtA activity, with an IC<sub>50</sub> value of 146.0 μM, and significantly reduced bacterial adherence to fibronectin-coated surfaces. The present results indicate that the underlying mechanism of action of compound <b>1</b> is associated with the inhibition of SrtA-mediated <i>S</i>. <i>aureus</i> adhesion to fibronectin, thus potentially serving as an SrtA inhibitor.
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