Isolation and Structure Elucidation of New Metabolites from the Mariana-Trench-Associated Fungus <i>Aspergillus</i> sp. SY2601

Abstract

Fungi are important resource for the discovery of novel bioactive natural products. This study investigated the metabolites produced by Mariana-Trench-associated fungus Aspergillus sp. SY2601 in EY liquid and rice solid media, resulting in the isolation and structure determination of 28 metabolites, including five new compounds, asperindopiperazines A–C (1–3), 5-methoxy-8,9-dihydroxy-8,9-deoxyaspyrone (21), and 12S-aspertetranone D (26). Structures of the new compounds were elucidated based on extensive NMR spectral analyses, HRESIMS data, optical rotation, ECD, and 13C NMR calculations. The new compound 12S-aspertetranone D (26) exhibited antibacterial activity against both methicillin-resistant Staphylococcus aureus and Escherichia coli with MIC values of 3.75 and 5 μg/mL, respectively.

Keywords

• marine fungus
• <i>Aspergillus</i> sp. SY2601
• indolyl diketopiperazine
• aspyrone analogue
• putative meroterpenoid
• antimicrobial activity