Nitric oxide inhibitory iridoids as potential anti-inflammatory agents from Valeriana jatamansi.

Five new iridoids, jatadomins A-E (1-5), together with six known analogues (6-11) and one known sesquiterpenoid (12), were isolated from the roots of Valeriana jatamansi Jones. Their structures were determined by analysis of their NMR, HRESIMS, and electronic circular dichroism calculations (ECD) data. The biological evaluation revealed that compounds 1-6 had anti-inflammatory activities by inhibiting nitric oxide (NO) release in LPS-induced murine microglial BV-2 cells, with IC values of 24.4, 9.2, 21.2, 25.9, 30.6, and 0.4 μM, respectively. Further molecular docking studies revealed a potential mechanism for NO inhibition by the bioactive compounds.