Two New Pentadepsipeptides from the Mangrove Fungus <i>Aspergillus</i> sp. SCSIO 41443.

Abstract

<b>Background</b>: Mangrove fungi are a prolific source of structurally diverse natural products. Among these, natural peptides with varied biological activities hold high commercial value and have been successfully developed into drugs for treating numerous diseases. <b>Methods</b>: Following rice solid-state fermentation of the strain, extracellular metabolites were extracted from the culture filtrate to obtain a crude extract. Cyclic depsipeptides were isolated from the crude extract by silica gel vacuum liquid chromatography for preliminary fractionation and enrichment, followed by high-performance liquid chromatography (HPLC) purification. The structures of the compounds were determined based on extensive spectroscopic analysis (1D and 2D NMR, ESI-MS-MS analysis) and Marfey's method for amino acid configuration assignment. <b>Results</b>: Ultimately, two new compounds, aspertides F (<b>1</b>) and G (<b>2</b>), and three known compounds, aspertides C, D, and A (<b>3</b>-<b>5</b>), were identified. The bioassays indicated that these compounds exhibited weak activity against acetylcholinesterase and neuraminidase. <b>Conclusions:</b> The research findings on this strain have not only enriched the metabolic resource library of mangrove fungi but also highlighted their diverse biological activities and significant application potential.