Cytotoxic Polyketide Metabolites from a Marine Mesophotic Zone Chalinidae Sponge-Associated Fungus sp. NBUF144.

Two new polyketide natural products, globosuxanthone F (), and 2'-hydroxy bisdechlorogeodin (), were isolated from the fungus sp. NBUF144, which was derived from a 62 m deep Chalinidae family sponge together with four known metabolites, 3,4-dihydroglobosuxanthone A (), 8-hydroxy-3-methylxanthone-1-carboxylate (), crosphaeropsone C (), and 4-megastigmen-3,9-dione (). The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR and high-resolution electrospray ionization mass spectra (HRESIMS) data. The absolute configuration of was further established by single-crystal X-ray diffraction studies. Compounds - were evaluated for cytotoxicity towards CCRF-CEM human acute lymphatic leukemia cells, and it was found that had an IC value of 0.46 µM.