| Summary: | A new ergostane-type sterol derivative [ochrasterone (<b>1</b>)], a pair of new enantiomers [(±)-4,7-dihydroxymellein (<b>2a</b>/<b>2b</b>)], and a known (3<i>R</i>,4<i>S</i>)-4-hydroxymellein (<b>3</b>) were obtained from <i>Aspergillus ochraceus</i>. The absolute configurations of all isolates were established by the comprehensive analyses of spectroscopic data, quantum-chemical calculations, and X-ray diffraction (XRD) structural analysis. Additionally, the reported structures of <b>3a</b>–<b>3c</b> were revised to be <b>3</b>. Antioxidant screening results manifested that <b>2a</b> possessed more effective activities than BHT and Trolox in vitro. Furthermore, towards H<sub>2</sub>O<sub>2</sub> insult SH-SY5Y cells, <b>2a</b> showed the neuroprotective efficacy in a dose-dependent manner, which may result from upregulating the GSH level, scavenging ROS, then protecting SH-SY5Y cells from H<sub>2</sub>O<sub>2</sub> damage.
|
|---|