Discovery of β‐Dihydroagarofuran‐Type Sesquiterpenoids from the Leaves of <i>Tripterygium wilfordii</i> with Neuroprotective Activities

Abstract

Main observation and conclusion Nine undescribed dihydro‐β‐agarofuran sesquiterpenoid derivatives (1—9), along with a known analogue (10), were obtained from the leaves of Tripterygium wilfordii . Their gross structures were determined via extensive spectroscopic data, and the absolute configurations were elucidated by means of single‐crystal X‐ray diffraction analysis and electron circular dichroism (ECD) techniques, which include ECD exciton chirality, octant rule of saturated cyclohexanone and comparison between the experimental and calculated ECD spectra. All the isolated compounds were tested for their neuroprotective activities against H 2 O 2 ‐induced cell injury in human neuroblastoma SH‐SY5Y cells. Compounds 5 and 6 improved cell viability by 16.15% and 15.12% compared with the H 2 O 2 treated group at 25 μmol·L –1 , respectively.