Scopularides Revisited: Molecular Networking Guided Exploration of Lipodepsipeptides in Australian Marine Fish Gastrointestinal Tract-Derived Fungi

Abstract

Chemical analysis of a cultivation of an Australian Mugil mullet gastrointestinal tract (GIT) derived fungus, Scopulariopsis sp. CMB-F458, yielded the known lipodepsipeptides scopularides A (1) and B (2). A comparative global natural product social (GNPS) molecular networking analysis of ×63 co-isolated fungi, detected two additional fungi producing new scopularides, with Beauveria sp. CMB-F585 yielding scopularides C−G (3−7) and Scopulariopsis sp. CMB-F115 yielding scopularide H (8). Structures inclusive of absolute configurations were assigned by detailed spectroscopic and C3 Marfey’s analysis, together with X-ray analyses of 3 and 8, and biosynthetic considerations. Scopularides A−H (1−8) did not exhibit significant growth inhibitory activity against a selection of Gram positive (+ve) and negative (−ve) bacteria, a fungus, or a panel of three human carcinoma cell lines.

Keywords

• <i>Scopulariopsis</i> sp.
• <i>Beauveria</i> sp.
• lipodepsipeptides
• scopularides
• GNPS
• marine fungal biodiscovery