Antioxidant Activities and Phytochemicals of Leaf Extracts from 10 Native Rhododendron Species in Taiwan

Table 4

Antioxidant activities and contents of major phytochemicals of the BuOH fraction from leaves of R. pseudochrysanthum.

Phytochemicals	Contents; (mg/g of BuOH fraction)	IC50 (μM)		Reducing power (μM CE/mM )
		DPPH radical scavenging	Superoxide radical scavenging
1	13.2 ± 1.4	6.8 ± 0.5^CD	45.4 ± 0.3^B	1000 ± 34^AB
2	52.0 ± 2.8	11.6 ± 0.3^A	8.6 ± 0.3^E	727 ± 76^D
3	67.3 ± 6.4	11.2 ± 0.3^A	45.6 ± 1.7^B	1074 ± 35^A
4	13.4 ± 0.8	6.1 ± 0.3^D	107.5 ± 2.4^A	917 ± 68^ABC
5	23.8 ± 1.6	7.8 ± 0.7^C	36.9 ± 0.1^C	834 ± 14^BCD
6	11.1 ± 0.9	9.6 ± 0.4^B	24.9 ± 1.3^D	753 ± 59^CD

The results are presented as means ± SD (n = 3). Different letters within a column indicate a significant difference at the P < 0.05 level according to Scheffe’s test. The reducing power was calculated as (+)-catechin (1) equivalents (CE).