Sesqui- and Diterpenoids from the Radix of Curcuma aromatica

Eight new sesquiterpenoids (1-8), two new diterpenoids (9 and 10), and 17 known sesqui- and diterpenoids (11-27) were isolated from the radix of Curcuma aromatica. Among these compounds, 1 is an unprecedented guaiane with unique cyclopropane and furan functionalities, and 9 is the first atisane diterpenoid isolated from a Curcuma species. Their 2D and 3D structures were established using HRESIMS and spectroscopic methods, including ECD and IECD data. The antioxidant activities of compounds 1-27 were evaluated based on their ability to protect PC12 cells against H₂O₂-induced damage, with 1, 2, 5-8, 11, 12, 14, 16, 18, and 19 exhibiting notable antioxidant effects on oxidative injury induced by H₂O₂.