Secondary metabolites from a mangrove-derived fungus Aspergillus sp. WHUF0343

Abstract:

[Objective] To investigate secondary metabolites of the mangrove-derived fungus Aspergillus sp. WHUF0343 from the root soil of an unidentified mangrove plant sample collected in Yalong Bay, Sanya, China, and their activity. [Methods] The column chromatography on silica gel and Sephadex LH-20, and semi-preparative high-performance liquid chromatography (HPLC) were used to isolate and purify the secondary metabolites from the fermented extract of Aspergillus sp. WHUF0343. Their structures were elucidated by modern spectroscopy methods such as nuclear magnetic resonance (NMR) and mass spectrometry (MS) combined with relevant literature data. Their antibacterial and cytotoxic activities were evaluated by broth microdilution assay and MTS assay, respectively. [Results] Ten compounds were isolated, which were respectively identified as isoechinulin A (1), neoechinulin A (2), neoechinulin E (3), preechinulin (4), neoechinulin D (5), variecolorin J (6), dehydroechinulin (7), questinol (8), emodin (9) and catenarin (10). Compounds 2, 9 and 10 exhibited moderate inhibitory activities against Helicobacter pylori, Staphylococcus aureus and their drug-resistant strains. Compound 1 demonstrated cytotoxic activities against malignant melanoma cell line B16, human hepatocellular carcinoma cell line HepG2 and human breast cancer cell MCF-7. [Conclusion] Aspergillus sp. WHUF0343 has potential research value in microbial drugs.