Table 1.

The antioxidant activities of procyanidin B2, epicatechin, epigallocatechin, taxifolin, quercetin, and rutin.

Flavonoid	The Antioxidant Activities
Procyanidin B2	Procyanidin B2, a widely distributed dimer in natural procyanidins, protects colonic cells against oxidative stress-induced injury [18].
Epicatechin	Epicatechin can exert anti-inflammatory and antioxidant effects, and it can pass through the blood brain barrier to provide neuroprotection [19].
Epigallocatechin	Two most important antioxidants in tea are epigallocatechin gallate and epigallocatechin, and the A ring of epigallocatechin has been demonstrated to be an antioxidant site [20].
Taxifolin	Taxifolin is a free radical scavenger, and its antioxidant capacity is superior to ordinary flavonoids [21].
Quercetin	Quercetin, a ubiquitously distributed flavonoid in plants, has a potent free radical scavenging capacity [22].
Rutin	The antioxidant activity is considered as one of the important pharmacological effects of rutin [23].