Bioactive 3,8-Epoxy Iridoids from Valeriana jatamansi.

Twelve 3,8-epoxy iridoids, including four new compounds, jatamanins R-U (1-4), and eight known compounds (5-12), were obtained from the roots and rhizomes of Valeriana jatamansi. The structures were elucidated from analysis of spectroscopic data. The absolute configurations of 1-4 were determined by comparison of experimental and literature ECD spectra. Moreover, the compounds were evaluated for cytotoxic effects against glioma stem cells, inhibition of NO production, activity against influenza A virus and reversal of multidrug resistance of HepG2/ADR cells. Compounds 9 and 12 showed significant cytotoxic potency against GSC-18# (IC =1.351 and 4.439 μg ml , respectively) and GSC-3# (IC =10.88 and 6.348 μg ml , respectively) glioma stem cells, while compound 12 was also slightly less potent against GSC-12# (IC =13.45 μg ml ) glioma stem cell growth. In addition, compounds 9 and 12 displayed obvious inhibition of NO production (IC =4.6 and 15.8 μm, respectively).