Structure and antioxidant ability of flavonoids from leaves of Paederia lanuginosa from Quangnam, Vietnam

Abstract

Three flavonoids (FLVs) were isolated from the EtOAC extract of leaves of Paederia Lanuginose, including kaempferol (KF), quercetin (QCT), and quercitrin (QCTR). Their structures were analyzed and confirmed by the combination of the NMR spectroscopies and literature data. Their antioxidant activities were also examined in-silico in the aqueous solution at pH 7.4 by using the density functional theory. All three of FLVs were predicted to be good antioxidants in the polar environment, with koverall are 6.2×106, 8.0×106, and 1.4×106, respectively. The main distribution into their capacity of antioxidant in the aqueous solution at pH 7.4 belongs to the dianion state, whereas the anion state does not make any distribution. The hydroxyl substitution at the O‒3ʹ site as well as the glycosidic linkage at the O‒3 site of KF is almost not impacted its antioxidant ability.

Keywords

• flavonoids
• paederia lanuginose
• antioxidant
• rate constant
• single electron transfer