[Structure-activity relationships of phenylethanoid glycosides in plants of Cistanche salsa on antioxidative activity].

Objective: To study the structure-activity relationships of phenylethanoid glycosides in plants of Cistanche salsa on antioxidative activity.

Methods: By the assay systems of DPPH*, the antioxidant activity of six phenylethanoid glycosides from plants of Cistanche salsa was determined to investigate the relationship between the antioxidant activities and phenylethanoid glycosides's structural characteristics.

Results: The antioxidative activity of phenylethanoid glycosides was variant with dose-dependent effect. The sequence of the strength of the antioxidative activity of the six components was shown to be 2'-Acetylacteoside > Acteoside > or = Tubuloside B > or = Isoacteoside > Echinacoside > Cistanoside A.

Conclusion: The antioxidative activity of phenylethanoid glycosides is related to the number of phenolic hydroxyl, steric hindrance, 2-acetyl on the middle glucopyranose, and the location of phenolic hydroxyl. Additionally, it may be related to the alpha, beta-unsaturated ketone of phenl-2-propenoyl.