New coumarin glycosides from endemic Prangos heyniae H. Duman & M.F. Watson

Two new coumarin glycosides, named 7-methoxy isoarnottinin 4'-O-β-ᴅ-glucopyranoside and 7-methoxy isoarnottinin 4'-O-rutinoside (1 and 2) along with six known compounds (3-8) were isolated from the roots of Prangos heyniae, an endemic plant of Turkey. 1-methylethyl 6-O-D-apio-β-ᴅ-furanosyl-β-ᴅ-glucopyranoside (7) and cnidioside A (8) have been obtained from the genus Prangos for the first time. Structures of isolated compounds were established using spectroscopic methods (1 D and 2 D NMR, HR-MS, UV and IR). Moreover, all extracts and isolated compounds were evaluated for their cytotoxic activity against NIH/3T3, HK-2, A-549, MCF-7, PC-3 and SH-SY5Y cell lines by WST-1 method. One of the new coumarin glycosides, 7-methoxy isoarnottinin 4'-O-β-ᴅ-glucopyranoside (1) exhibited selective cytotoxic activity against SH-SY5Y cells with IC₅₀ value of 31.41 ± 1.04 μM.