The ortho hydroxy-amino group: Another choice for synthesizing novel antioxidants

Four ortho hydroxy-amino derivatives have been designed based on the structures of flavonoids to explore the effect of the ortho hydroxy-amino group on the antioxidant properties of molecules, and their bond dissociation enthalpies (BDE), ionization potentials (IP), the highest occupied molecular orbitals (HOMO), and spin densities have been calculated. The results reveal that the ortho hydroxy-amino group plays an important role in promoting the antioxidant properties of molecules because of its lowering effect on BDE, IP, and spin density. The derivatives with ortho hydroxy-amino group show stronger antioxidant activity than the derivatives with mono hydroxy or ortho dihydroxy group. Thus, the ortho hydroxy-amino group can be used as another potential functional group to synthesize novel antioxidants as guessed. (c) 2006 Elsevier Ltd. All rights reserved.