Ultrafast Excited-State Dynamics of Kynurenine, a UV Filter of the Human Eye

被引：68

作者：

Sherin, Peter S. ^{[1
]}

Grilj, Jakob ^{[2
]}

Tsentalovich, Yuri P. ^{[1
]}

Vauthey, Eric ^{[2
]}

机构：

[1] RAS, SB, Int Tomog Ctr, Novosibirsk 630090, Russia

[2] Univ Geneva, Dept Phys Chem, CH-1211 Geneva 4, Switzerland

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2009年 / 113卷 / 14期

基金：

俄罗斯基础研究基金会; 瑞士国家科学基金会;

关键词：

SOLVATION DYNAMICS; PHOTOPHYSICAL PROPERTIES; HUMAN LENS; RADIATIONLESS DEACTIVATION; INTERNAL-CONVERSION; CHARGE SEPARATION; PROTON-TRANSFER; FLUORESCENCE; MOLECULES; SOLVENT;

D O I：

10.1021/jp900541b

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：

The excited-state dynamics of kynurenine (KN) has been examined in various solvents by femtosecond-resolved optical spectroscopy. The lifetime of the S, state of KN amounts to 30 ps in aqueous solutions, increases by more than 1 order of magnitude in alcohols, and exceeds 1 ns in aprotic solvents such as DMSO and DMF, internal conversion (IC) being shown to be the main deactivation channel. The IC rate constant is pH independent but increases with temperature with an activation energy of about 7 kJ/mol in all solvents studied. The dependence on the solvent proticity together with the observation of a substantial isotope effect indicates that hydrogen bonds are involved in the rapid nonradiative deactivation of KN in water. These results give new insight into the efficiency of KN as a UV filter and its role in cataractogenesis.

引用

页码：4953 / 4962

页数：10

共 70 条

[1] Cysteine is the initial site of modification of α-crystallin by kynurenine [J].