Euphanoids A and B, two new lathyrane diterpenoids with nitric oxide (NO) inhibitory activity from Euphorbia kansuensis

Two new lathyrane diterpenoids, euphanoids A and B (1 and 2), along with five known compounds (3-7) were isolated from the roots of Euphorbia kansuensis. Their structures were elucidated by spectroscopic analysis, and the absolute configuration of 1 was determined by single crystal X-ray diffraction. All of the isolates were screened for the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells, and compounds 1 and 2 showed pronounced inhibition on NO production with IC₅₀ values of 4.7 and 9.5 μM, respectively, being more active than the positive control, quercetin (IC₅₀ = 10.8 μM).