New diterpenoids from Euphorbia wallichii with antioxidant activity

Thirteen novel diterpenoids, comprising seven tiglianes (walliglianes G−M, 1−7), four rhamnofolanes (wallinofolanes A−D, 8−11), and two daphnanes (wallaphnanes A and B, 12 and 13), together with two known rhamnofolane diterpenoids (euphorwallside H and euphorwallside I, 14 and 15), were isolated and characterized from Euphorbia wallichii (E. wallichii). The chemical structures of these compounds were elucidated through nuclear magnetic resonance (NMR), mass spectrometry (MS), and quantum chemical calculations. Compounds 9 and 11 demonstrated protective effects against H₂O₂-induced BV-2 microglial cell damage. Molecular docking analyses indicated that compound 9 exhibited binding affinity to the anti-oxidant-related targets HMGCR, GSTP1, and SHBG.