Table 1.

Antioxidant activity of the isolated compounds and standards.

Tested compounds	% radical scavenging activity (RSA)	Reducing power assay (RPA)	Total antioxidant capacity∗
Bergenin (1)	6.858 ± 0.329	0.055 ± 0.002	49.159 ± 3.136
11-O-Galloylbergenin (2)	87.26 ± 1.671	1.315 ± 0.027	951.50 ± 109.64
Ascorbic acid	97.85 ± 0.623	3.351 ± 0.034	2478.36 ± 173.81
Gallic acid	98.12 ± 0.931	1.435 ± 0.031	2201.05 ± 152.33
Quercetin	98.35 ± 0.871	1.772 ± 0.041	2030.29 ± 134.51
α-Tocopherol	92.26 ± 0.547	22.026 ± 0.074	565.17 ± 25.32

Each reading is mean (n = 3) ± SD (standard deviation). For RSA and RPA, 100 and 25 μg/mL, respectively, were used. ^∗As ascorbic acid equivalent (μmol/mg).