Chromone-Derived Polyketides from the Deep-Sea Fungus FS431.

Five new chromone-derived polyketides phaseolorins A-F (⁻), together with nine known compounds, were isolated from the deep-sea derived fungus FS431. The structures of new compounds were determined by analysis of their NMR and high-resolution electrospray ionization mass spectroscopy (HRESIMS) spectroscopic data. The absolute configurations were confirmed by chemical transformations, extensively experimental electron capture detection (ECD) calculations, or X-ray crystallography. Among them, compound represented the first example for a new family of chromone derivative possessing an unprecedented recombined five-member -lactone ring. Moreover, the new compounds (⁻) were evaluated for in vitro cytotoxic activities against a panel of human cancer cell lines.