Diterpenoids and Diacetylenes from the Roots of with Inhibitory Effects on Nitric Oxide Production.

Bioactivity-guided isolation of a MeOH extract of led to the isolation of four new -pimarane diterpenoids (-) and a diacetylene () together with 21 known compounds (-). Their structures were established based on the interpretation of one- and two-dimensional NMR and HRESIMS data. The absolute configurations of the new isolates were determined by electronic circular dichroism data analysis, single crystal X-ray diffraction, and Mosher's esterification method. All compounds exhibited inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages with IC values ranging from 1.1 to 69.4 μM.