Diterpenoids and triterpenoids from Triadica rotundifolia and their effects on microglial nitric oxide production.

Four new diterpenoids (1-4), three new triterpenoids (12-14), and seven known diterpenoids (5-11) were obtained from an aqueous EtOH extract of the aerial parts of Triadica rotundifolia. The structures of new compounds were determined by spectroscopic techniques. Their absolute configurations were verified via single-crystal X-ray diffraction data, Mo2(OAc)4 induced electronic circular dichroism (ECD), and ECD calculations. The antineuroinflammatory effects of the isolates were assessed by inhibiting NO production in LPS-induced BV-2 microglial cells. Compared with the positive control minocycline (IC50 = 16.1 µM), compounds 3, 8, 11 showed moderate inhibitory activities with IC50 values of 35.9, 17.0, 31.5 µM, respectively.