Table 1.

IC₅₀ values for DPPH radical scavenging activity from different parts of QG plants and from isolated compounds.

Extract	IC50 (μg/mL)	Compound	IC50 (μM)
Leave	19.15 ± 0.22	1	>100 h
Branch	33.07 ± 0.34	2	>100 g
Bark	10.58 ± 0.85	3	74.23 ± 0.39 f
Wood	16.14 ± 0.80	4	43.37 ± 0.57 e
l-ascorbic acid	6.04 ± 0.27	5	28.80 ± 1.02 d
		6	15.10 ± 0.34 b
		7	12.15 ± 0.18 a
		l-ascorbic acid	27.41 ± 1.28 c

Values are expressed as mean ± S.D. of three determinations. Values bearing different superscripts (a–g) in same columns are significantly different (p < 0.05).