A multivariate study on flavonoid compounds scavenging the peroxynitrite free radical

The goal of this study is to select electronic properties (variables or descriptors) responsible for peroxynitrite scavenging ability of a set of 24 flavonoids. To do so, electronic parameters were calculated by using DFT and chemometric methods (Principal Component Analysis, Hierarchical Cluster Analysis and K-Nearest Neighbor) in order to build models able to establish relationships between electronic features and the antioxidant activity presented by the compound studied. According to these models, three electronic variables can be considered important to discriminate active and inactive flavonoid compounds: HOMO energy and net charge upon C3' and C4'. The features found as responsible for the antioxidant activity of the studied flavonoid compounds are consistent with previous experimental results obtained from structure-activity relationship (SAR) found in the literature and aims to propose a general theoretical mechanism to explain the peroxynitrite scavenging ability of the flavonoid compounds. The results obtained can also bring improvements in the search for confirming the antioxidant activity of flavonoid compounds. (c) 2006 Elsevier B.V. All rights reserved.