中国科学B辑(英文版)
中國科學B輯(英文版)
중국과학B집(영문판)
SCIENCE IN CHINA(SCIENTIA SINICA)
2002年
4期
398-406
,共9页
储高升%张淑娟%姚思德%韩镇辉%都志文%张志成
儲高升%張淑娟%姚思德%韓鎮輝%都誌文%張誌成
저고승%장숙연%요사덕%한진휘%도지문%장지성
Phe%pulse radiolysis%SO4-radical%oxidation%mechanism
By using time-resolved kinetic spectrophotometry and pulse radiolysis technique, the oxidation of Phe by radical has been investigated both in aqueous and water/acetonitrile mixed solutions. The results reveal that attack of the oxidizing SO4-radical on Phe leads directly to the formation of Phe cation radical 3 with a strong absorption peak at 310 nm, then it proceeds in three competitive reactions via either hydroxylation, deprotonation or decarboxylation, which were found to be strongly dependent upon the ionization state of the substitutes -COOH and -NH2 and the nature of the solvents. Decarboxylation takes place only when the carboxyl group is deprotonated. At high pH deprotonation of Phe cation radical 3 is much easier to occur than that in neutral or acid solutions. Moreover, with addition of acetonitrile, deprotonation is more predominant than hydroxylation, whereas in aqueous solutions hydroxylation is much easier to occur.
