NO inhibitory diterpenoids as potential anti-inflammatory agents from Euphorbia antiquorum

Abstract Two new ent-atisane-type diterpenoids (1 and 2), three new lathyrane-type diterpenoids (3–5), and seven known analogues (6–12) were isolated from Euphorbia antiquorum. The structures of these diterpenoids were established by analysis of their NMR, MS, and electronic circular dichroism data. The anti-inflammatory activities were evaluated biologically and compounds 1, 4, 7, 8, and 10 displayed strong NO inhibitory effects with IC50 values less than 40 μM. The potential anti-inflammatory mechanism was also investigated using molecular docking and Western blotting.