In vitro neuroprotective activities of phenylethanoid glycosides from Callicarpa dichotoma

Ten phenylethanoid glycosides, forsythoside B, acteoside, 2'-acetylacteoside, poliumoside, brandioside, echinacoside, isoacteoside, cistanoside H and E-tubuloside E as well as a new compound, Z-tubuloside E, were isolated from the n-BuOH fraction of Callicarpa dichotoma Raeuschel (Verbenaceae) by bioactivity-guided fractionation using glutamate-injured primary cultures of rat cortical cells as a screening system. These phenylethanoid glycosides significantly attenuated glutamate-induced neurotoxicity at concentrations ranging from 0.1 to 10 microM.