Antioxidant and Antidiabetic Effects of Flavonoids: A Structure-Activity Relationship Based Study

Table 1

IC₅₀ values of flavonoids for DPPH, ABTS⁺, and xanthine oxidase inhibition assays.

Samples (µg/ml)	DPPH	ABTS^+	Xanthine oxidase
Ascorbic acid		—	—
Trolox	—		—
Allopurinol	—	—
Wogonin	>100		NA
Methyl ether (wogonin)	>200	>200	NA
Acetate (wogonin)	>200	>200	NA
Techtochrysin	>100		>100
8-Hydroxy-7-methoxyflavone			NA
Chrysin	>100	>100	>100
Norwogonin			NA
Acetate (norwogonin)	>100		NA
Isoscutellarein			>100
Hypolaetin			>100
Kaempferol
Quercetin
(+)-Catechin			NA
(−)-Epicatechin			NA

Values represent mean ± SEM (), NA: not active; capital letters represent Tukey’s test, small letters represent Dunnett’s test, and means not sharing a letter are significantly different ().