飞蓬属11种黄酮类化合物抗氧化活性的理论评价

Theoretical evaluation on anti-oxygenic activity of eleven flavonoids from Erigeron breviscapus

采用Wright等提出的组合的密度泛函理论方法,计算了短葶飞蓬中11种黄酮类化合物的O-H解离焓(O-H BDE)和电离势(IP),以此为理论指标评价了这些化合物的抗氧化活性。计算得11种黄酮类化合物的最低O-H BDE值,均低于或相近于单酚的O-H BDE值(361.12 kJ/mol)。发现8,9,7,1,3,4号化合物在非极性溶剂中清除自由基活性较强;11,9,1,3,6号化合物在极性溶剂中清除自由基活性较强;得出9,1,3号化合物无论在极性和非极性溶剂中,均具有较强的清除自由基活性,特别是9号化合物(灯盏花乙素)。

A kind of combined quantum chemistry method （ DFT/AM 1 ） which brought up by Wright and his partner was employed to calculate O-H bond dissociation enthalpies（BDEs） and ionization potentials （IPs） of eleven flavonoids that extracted from Erigeron breviscapus, by which their anfioxidant activities were evaluated. It was found that in non-polar solvents, the lowest O-H BDE value （361.12 kJ/mol）of the eleven compounds all lower than or equal to the O-H BDE value of monophenol, and compounds 8, 9, 7, 1, 3, g had the highest activity to scavenge free radicals. And in polar solvents, compounds 11, 9, 1, 3, 6 had the highest activity to scavenge free radicals. It could be concluded that in polar and non-polar solvents, compounds 9, 1, 3 had the better activity to scavenge free radicals, especially, compound 9 （Scutellarin） had the highest activity.