Antioxidant phenylpropanoid glycosides from Buddleja davidii.

Phytochemical investigations on the n-BuOH-soluble fraction of the whole plant of Buddleja davidii led to the isolation of the phenylpropanoid glycosides 1-10. Their structures were determined by 1D and 2D NMR spectroscopic techniques. All the compounds showed potent antioxidative activity in three different tests, with IC 50 values in the range 4.15-9.47 μM in the hydroxyl radical ( ˙OH) inhibitory activity test, 40.32-81.15 μM in the total ROS (reactive oxygen species) inhibitory activity test, and 2.26-7.79 μM in the peroxynitrite (ONOO−) scavenging activity test. Calceolarioside A ( 1) displayed the strongest scavenging potential with IC 50 values of (4.15 ± 0.07, 40.32 ± 0.09, 2.26 ± 0.03 μM) for ˙OH, total ROS and scavenging of ONOO−, respectively. [ABSTRACT FROM AUTHOR]