Phytother Res. 2003 Apr; 17(4): 417-9.

Secoiridoid glucosides with free radical scavenging activity from the leaves of Syringa dilatata.

Oh H, Ko EK, Kim DH, Jang KK, Park SE, Lee HS, Kim YC.

Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Korea.

Activity-guided fractionation of the EtOAc and MeOH extract of the leaves of Syringa dilatata NAKAI furnished one free radical scavenger, the secoiridoid glucoside oleuropein together with ligstroside and an iridoid glucoside, syringopicroside. Oleuropein interacted with the stable free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and showed an IC(50) value of 40.4 microM. L-Ascorbic acid as a positive control showed an IC(50) value of 50.3 microM.Copyright 2003 John Wiley & Sons, Ltd.