New iridoids from the roots of Valeriana dioscoridis Sm.

Four new iridoids (1-4), together with three known iridoids (5-7), one known flavonoid glycoside, three phenolic acids and one phytosterol were isolated from the roots of Valeriana dioscoridis. Their structures were elucidated by means of NMR spectroscopy and mass spectrometry. This is the first report on the phytochemical composition of the non-volatile constituents of V. dioscoridis and the occurrence of a bis-iridoid glycoside in the genus Valeriana. The antiproliferative effects of the iridoids (1-7) were evaluated against three human cancer cell lines of gynacological origin (HeLa, A2780 and T47D) at 10, 30 and 60 μM concentrations, using the MTT assay and they elicited modest antiproliferative activity when compared to the reference agent, cisplatin.