Isolation and antiproliferative activities of secondary metabolites from Sideritis germanicopolitana Bornm., Sideritis perfoliata L. and Sideritis libanotica Labill.

In this study, S. germanicopolitana Bornm., S. perfoliata L. and S. libanotica Labill., plants were examined phytochemically. Verbascoside (M1), apigenin-7-O-(6′′-O-p-coumaroyl)-β-D-glycopyranoside (M2) chlorogenic acid (M3), 3′-O-methylhypolaetin-7-O-(allosyl-(1→2)-glycoside) (M4), isoscutellerain-7-O-[6′′′-O-acetyl-allosyl-(1→2)-glycoside] (M5), 3′-O-methylhypolaetin-7-O-[6′′′-O-acetyl-allosyl-(1→2)-glycoside] (M6), Isoscutellerain-7-O-[6′′′-O-acetyl-allosyl-(1→2)-6′′-O-acetyl-glycoside] (M7), 3′-O-methylhypolaetin-7-O-[6′′′-O-acetyl-allosyl-(1→2)-6′′′-O-acetyl-glycoside] (M8) and sideridoside (M9) were isolated from methanol extract of Sideritis germanicopolitana. 4′-O-methylisoscutellerain-7-O-[6′′′-O-acetyl-allosyl-(1→2)-glycoside] (M10), ajugol (M11) and ajugoside (M12) were also isolated from methanol extract of Sideritis perfoliata L. From ethyl acetate extract of Sideritis perfoliata L., 13-epi-manoyl oxide (SP1), 2-oxo-13-epi-manoyl oxide (SP2), 2-β-hydroxy-13-epi-manoyl oxide (SP3), 7-acetyl-isofoliol (SP4), 2-β-format-13-epi-manoyl oxide (SP5), isolinearol (SP6), from ethyl acetate extract of Sideritis libanotica Labill. siderol (SL1) and sideridiol (SL2) were isolated. The structures of the isolated molecules were determined by spectroscopic methods such as NMR, MS and IR. Sideridoside (M9) and 2-β-format-13-epi-manoyl oxide (SP5) have been reported for the first time. The antiproliferative effect of the methanol extracts of the three different organs of the plants (stem, leaf and flower) and the isolated molecules against the A549, HeLa, Hep3B and FL cell lines was investigated by MTT and BrDU-Elisa methods. The kauren type terpenes (SP4, SP6, SL1 and SL2) were found to have high antiproliferative activity.