Isolation and characterization of diterpene glycosides from Siegesbeckia pubescens

Abstract Five new diterpenoid glycosides, siegesides A–E ( 1 – 5 ), along with the known compound darutoside ( 6 ) were isolated and characterized from the ethanol extract of Siegesbeckia pubescens . The structural elucidation of the isolates was accomplished by extensive HRESIMS and NMR analysis. Compounds 1 and 2 are epimers of 6 . All isolates were evaluated for their inhibition on the migration of MB-MDA-231 breast cancer cells induced by the chemokine epithelial growth factor, and compound 2 showed superior inhibitory activities in comparison with the positive control drug with IC 50 value of 0.27 μM.