Characteristics of the reaction between semiquinone radical anion of hypocrellin A and oxygen in aprotic media

被引：17

作者：

Hu, YZ ^{[1
]}

Jiang, LJ ^{[1
]}

Chiang, LC ^{[1
]}

机构：

[1] ACAD SINICA,INST PHOTOG CHEM,BEIJING 100101,PEOPLES R CHINA

来源：

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY | 1996年 / 94卷 / 01期

关键词：

hypocrellin A; semiquinone radical anion; oxygen; conjugated base; electron transfer; proton transfer;

D O I：

10.1016/1010-6030(95)04206-7

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Hypocrellin A (HA), a hydroxylperylenequinone derivative, is an efficient phototherapeutic agent. The reactivity of the semiquinone radical anion of HA (HA(.-)) with O-2 in aprotic medium has been studied. Although the standard redox potential of the HA(.-)-HA couple (-360 mV vs. a normal hydrogen electrode (NHE)) is less negative than that of the O-2(.-)-O-2 couple (-500 mV vs. NHE), it appears that HA(.-) can still be oxidized with oxygen. The electron transfer is accompanied by a proton transfer between one of the phenolic hydroxyl groups of HA and O-2(.-) yielding the conjugated base of HA (HA(b)(-)) and hydrogen peroxide. On the basis of the results obtained from spectrophotometric, electron spin resonance spin-trapping and CCl4-inhibiting experiments, a reasonable reaction pathway was proposed for the oxidation of HA(.-) with O-2 in aprotic media.

引用

页码：37 / 41

页数：5