Two New Chromone Glycosides from the Roots of Saposhnikovia divaricata

Five chromone glycosides were isolated from the water-soluble portions of 70% EtOH extract of the roots of Saposhnikovia divaricata, including two new chromone glycosides 1 and 2. The structures of the chromone glycosides were identified as (3'S)-3'-O-β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranosylhamaudol (1), (2'S)-4'-O-β-d-apiofuranosyl-(1 → 6)-β-d-glucopyranosylvisamminol (2), 3'-O-glucopyranosylhamaudol (3), 4'-O-β-d-glucopyranosylvisamminol (4), and 4'-O-β-d-glucopyranosyl-5-O-methylvisamminol (5) on the basis of extensive spectroscopic methods, and the absolute configurations of the new compounds were elucidated by the electronic circular dichroism (ECD) calculation and acid hydrolysis. The cytotoxic activities of the glycosides 1 - 5 against three human cancer cell lines (PC-3, SK-OV-3, and H460) were evaluated. The result showed that compounds 1 - 5 had weak cytotoxic activities against the human cancer cell lines with IC₅₀ values in the range of 48.54 ± 0.80 - 94.25 ± 1.45 μm.