红树来源真菌Daldinia eschscholtzii HJ004发酵产物中三个新的次级代谢产物

Three new compounds, together with eight known compounds, were isolated from the mangrove-derived fungus Daldinia eschscholtzii HJ004. The structure of 8-ethyl-7-hydroxy-5-carboxyl-2,3-dimethylchromone (1) was extensively elucidated and characterized by HRESIMS, 1D and 2D NMR, and single-crystal X-ray crystallography. The absolute configurations of felinone C (2) and helicascolide G (3) were determined by using electronic circular dichroism (ECD) method or comparing circular dichroism (CD) data with the literature. The radical scavenging capabilities of the 11 compounds obtained were tested by total antioxidant capacity assay kit with a rapid ABTS method. Among them 4 compounds exhibited stronger antioxidant activity with IC50 values range from 5.57 mu mol/L to 195.03 mu mol/L, than the positive control trolox (IC50=292.12 mu mol/L). These results indicate that chromones have the potential values of developing antioxidants.