Structure and Absolute Configuration of Fumiquinazoline L, an Alkaloid from a Gorgonian-Derived <i>Scopulariopsis</i> sp. Fungus

Fumiquinazoline L (<b>1</b>), an alkaloid with a heptacyclic skeleton formed via a bridging hemiaminal linkage, was isolated from a gorgonian-derived <i>Scopulariopsis</i> sp. fungus. The structure and absolute configuration of the new compound were identified by comprehensive spectroscopic data and X-ray diffraction analysis. During acid hydrolysis of <b>1</b>, the isomerization of the valine residue was observed and also studied in different conditions. Fumiquinazoline L (<b>1</b>) showed no cytotoxic or antibacterial activities.