Oblongolides from endophytic fungus Phoma bellidis Neerg. harbored in Tricyrtis maculata (D. Don) J.F.Macbr

Five previously undescribed oblongolides, namely phomaones A-E, along with four known compounds, were isolated from the endophytic fungus Phoma bellidis Neerg.. Their structures and absolute configurations were determined by extensive experimental spectroscopic methods as well as single crystal X-ray diffractions, ECD calculations and GIAO 13C NMR calculations. Phomaone A represent the first example of oblongolides with glycol directly linked by two C–C bonds, and its biosynthetic pathway were proposed. The cytotoxicity of obtained compounds was evaluated against human cancer cell lines MCF-7, DU145, and SW480. All compounds except phomaone A showed the cytotoxicity against MCF-7 with IC50 value ranging from 12.45 to 49.84 μM. Nine oblongolides were isolated from endophytic fungus Phoma bellidis Neerg. and some of them showed cytotoxicity activity. [Display omitted] •Five undescribed oblongolides were obtained from endophytic fungus Phoma bellidis Neerg..•Their configurations were determined through X-ray, ECD and 13C NMR calculation.•In vitro bioassay, the cytotoxicity for the isolated compounds were evaluated.