Two new phenolic glycosides from the roots of Iris domestica (L.) Goldblatt & Mabb and their cytotoxic activity

Two new phenolic glycosides, Diplostephioside D (1) and Diplostephioside E (2) together with ten known phenols (3-12) were isolated from the dried roots of Iris domestica (L.) Goldblatt & Mabb. Among them, compounds 4-9 have not been reported previously from the family Iridaceae. The chemical structures were elucidated based on extensive spectroscopic experiments, including 1D and 2D NMR as well as HR-ESI-MS, and comparison with those reported in the literature. All of the isolated compounds were evaluated for their cytotoxic activity against HeLa cells. Compounds 1, 2, 4, 8 and 12 showed cytotoxic activities with IC₅₀ values ranging from 13.52 ± 1.52 to 53.33 ± 1.40 μM.