DFT study on the radical scavenging activity of β,β-dimethylacrylalkannin derivatives

Abstract

The radical scavenging activity of β,β-dimethylacrylalkannin derivatives has been studied by using density functional theory. The hydrogen bond property of the studied structures was investigated using the atoms in molecules theory. It turned out that the hydrogen bond is important for good radical scavenging activity. The hydrogen atom transfer for β,β-dimethylacrylalkannin derivatives is difficult to occur compared with the zero compound phenol. However, β,β-dimethylacrylalkannin derivatives appear to be good candidates for the one-electron transfer, particularly for β,β-dimethylacrylalkannin derivatives with electron-donating groups. Their naphthoquinone planar conformation and the extended electronic delocalisation between adjacent substituent groups determine low adiabatic ionisation potential (IP_a) values. The IP_a values of β,β-dimethylacrylalkannin derivatives with –NHPh, –N(CH₃)Ph, –N(CH₂CH₂)O and –N(CH₃)₂ groups are lower than that of the parent compound β,β-dimethylacrylalkannin, suggesting that these derivatives are expected to be the promising candidates for radical scavenging activity compounds. Taking this system as an example, we present an efficient method for the investigation of radical scavenging activity from theoretical point of view.

Keywords:

• β,β-dimethylacrylalkannin derivatives
• density functional theory
• radical scavenging activity
• hydrogen atom transfer mechanism
• one-electron transfer mechanism

Acknowledgements

Financial support from the Research Program of Sciences at Universities of Inner Mongolia Autonomous Region (NJzy08148) is gratefully acknowledged.