Free radical scavenging reactions of silybin and its analogues

シリビンとその類似体のラジカル捕捉反応

Fu, H.*; 勝村 庸介; Lin, M.; 室屋 裕佐*; 端 邦樹 

Fu, H.*; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Hata, Kuniki

Flavonoid silybin has attracted much attention due to its potential application in medicine. In this work, the reactions of silybin and analogues with oxidizing free radicals, hydroxyl and azide radicals, were measured by pulse radiolysis techniques. The structure-activity relationships of these analogues were also investigated by theoretical calculations. The rate constants and absorption spectra for the reactions of silybin and its analogues with various oxidizing radicals have been measured. The difference of heat of formation between parent molecule and its free radical (HOF) was employed as a theoretical index to characterize the O-H bond dissociation energy (BDE) of the flavanones. A comparison of HOF could suggest that position 4' is the most easily attacked site.