New diterpenoids from Euphorbia wallichii with antioxidant activity

Thirteen novel diterpenoids, including seven tiglianes (walliglianes G-M, 1-7), four rhamnofolanes (wallinofolanes A-D, 8-11), and two daphnanes (wallaphnanes A and B, 12 and 13), along with two known rhamnofolane diterpenoids (euphorwallside H and euphorwallside I, 14 and 15), were isolated and characterized from Euphorbia wallichii. Through the analysis of NMR, MS, and quantum chemical calculations, the chemical structures of these compounds were determined. Compounds 9 and 11 displayed protective effects on H₂O₂-induced BV-2 microglial cell damage. The molecular docking studies revealed that compound 9 could bind to the antioxidant-related targets HMGCR, GSTP1, and SHBG.