Antibacterial Secondary Metabolites from Marine-Derived Fungus sp. IMCASMF180035.

Four new secondary metabolites, including one [anthracenone-xanthene] derivative aspergiloxathene A (), one penicillide analogue, Δ-1'-dehydropenicillide (), and two new phthalide derivatives, 5-methyl-3-methoxyepicoccone () and 7-carboxy-4-hydroxy-6-methoxy-5-methylphthalide (), together with four known compounds, yicathin C (), dehydropenicillide (), 3-methoxyepicoccone (), 4-hydroxy-6-methoxy-5-methylphthalide (), were identified from the marine-derived fungus sp. IMCASMF180035. Their structures were determined by spectroscopic data, including high-resolution electrospray ionization mass spectrometry (HRESIMS), 1D and 2D nuclear magnetic resonance (NMR) techniques. Compound was identified as the first jointed molecule by xanthene and anthracenone moieties possessing an unprecedented carbon skeleton with spiro-ring system. All compounds were evaluated activities against , methicillin resistant (MRSA), , , , and Compound showed significant inhibitory effects against and MRSA, with minimum inhibitory concentration (MIC) values of 5.60 and 22.40 µM. Compounds and exhibited potent antibacterial activities against , with MIC values of 21.73 and 21.61 µM, respectively.