Antioxidant Activities and Phytochemicals of Leaf Extracts from 10 Native Rhododendron Species in Taiwan
Table 1
Antioxidant activities of methanolic extracts from leaves of 10 native Rhododendron species.
Specimens
Yield (wt%)
IC50 (μg/mL)
Reducing power (mg CE/g)
Total phenolic content (mg GAE/g)
DPPH radical scavenging
Superoxide radical scavenging
Ferrous ion chelating
R. breviperulatum
18.4
8.8 ± 1.6CD
24.3 ± 2.4ABC
665.3 ± 9.8F
320 ± 18BC
265 ± 2B
R. ellipticum
33.4
14.2 ± 0.9AB
15.7 ± 1.2CD
1095.9 ± 31.3B
298 ± 15BCD
221 ± 16CD
R. formosanum
18.2
10.7 ± 1.0BCD
20.1 ± 1.3BCD
928.8 ± 38.1CD
282 ± 5CDE
222 ± 16CD
R. kanehirai
22.5
7.7 ± 0.4D
33.9 ± 2.7A
429.1 ± 14.8G
328 ± 8B
238 ± 5BC
R. mariesii
18.0
14.7 ± 0.4A
29.0 ± 2.8AB
515.3 ± 4.8G
225 ± 11F
165 ± 7E
R. oldhamii
29.1
7.5 ± 0.9D
19.6 ± 1.0BCD
714.1 ± 60.0EF
326 ± 19B
264 ± 9B
R. pseudochrysanthum
6.8
7.5 ± 0.7D
12.4 ± 0.8D
1344.4 ± 18.5A
387 ± 9A
319 ± 17A
R. rubropilosum var. rubropilosum
11.4
12.1 ± 1.5ABC
24.5 ± 1.2ABC
804.9 ± 22.0DE
263 ± 9DEF
193 ± 7DE
R. rubropilosum var. taiwanalpinum
16.7
10.4 ± 1.2BCD
34.0 ± 1.2A
774.1 ± 31.9EF
243 ± 6EF
198 ± 5DE
R. simsii
9.2
11.8 ± 1.0ABC
31.6 ± 2.9A
961.2 ± 63.3C
277 ± 15CDE
219 ± 4CD
(+)-Catechin
—
2.1 ± 0.3E
16.6 ± 0.9CD
>2000
—
—
The results are presented as means ± SD (n =3). Different letters within a column indicate significant difference at the P < 0.05 level according to Scheffe’s test. The reducing power was calculated as (+)-catechin equivalents (CE). The total phenolic content was calculated as gallic acid equivalents (GAE).