Investigation on the fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by certain estrogens and catechols

被引:14
作者
Anbazhagan, V. [1 ]
Kandavelu, V. [1 ]
Kathiravan, A. [1 ]
Renganathan, R. [1 ]
机构
[1] Bharathidasan Univ, Sch Chem, Tiruchirappalli 620024, India
关键词
2.3-diazabicyclo[2.2.2]oct-2-ene; fluorescence quenching; estrogens; catechols;
D O I
10.1016/j.jphotochem.2007.06.026
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 fluorescence quenching of singlet excited 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO), a fluorescent probe for antioxidants, by various estrogens and certain catechols has been investigated. The time resolved and steady state fluorescence quenching experiments were conducted in acetonitrile and dichloromethane. The bimolecular quenching rate constant (Q values are in the range of 10(7)-10(9) M-1 s(-1) for estrogens and 10(9)-10(10) M-1 s(-1) for catechols. In the case of estrogens, a direct hydrogen atom abstraction is proposed, while exciplex. induced quenching becomes competitive for catechols with electron donating (ED) substituents. The quenching mechanism was analysed on the basis of exciplex formation, deuterium isotopic effects and cyclicvoltammetric studies. Further, the invitro-antioxidant activity of estrogens and catechols were evaluated with rat liver catalase by gel electrophoresis. The data suggest the involvement of hydrogen atom transfer in the fluorescence quenching of DBO by estrogens and catechols. (C) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:204 / 212
页数:9
相关论文
共 56 条
[1]   Solvent effect on product distribution in photochemical pathways of alpha C-N versus beta C-C cleavage of n,pi* triplet-excited azoalkanes [J].
Adam, W ;
Moorthy, JN ;
Nau, WM ;
Scaiano, JC .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1997, 119 (24) :5550-5555
[2]   Photoreduction of azoalkane triplet states by hydrogen atom and charge transfer [J].
Adam, W ;
Moorthy, JN ;
Nau, WM ;
Scaiano, JC .
JOURNAL OF ORGANIC CHEMISTRY, 1996, 61 (25) :8722-8723
[3]  
[Anonymous], 1995, Angew. Chem
[4]   AUTOXIDATION OF BIOLOGICAL MOLECULES .1. THE ANTIOXIDANT ACTIVITY OF VITAMIN-E AND RELATED CHAIN-BREAKING PHENOLIC ANTIOXIDANTS INVITRO [J].
BURTON, GW ;
INGOLD, KU .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1981, 103 (21) :6472-6477
[5]   Reaction pathways involved in the quenching of the photoactivated aromatic ketones xanthone and 1-azaxanthone by polyalkylbenzenes [J].
Coenjarts, C ;
Scaiano, JC .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (15) :3635-3641
[6]   PROTEIN FLUORESCENCE, DYNAMICS AND FUNCTION - EXPLORATION OF ANALOGY BETWEEN ELECTRONICALLY EXCITED AND BIOCATALYTIC TRANSITION-STATES [J].
DEMCHENKO, AP .
BIOCHIMICA ET BIOPHYSICA ACTA-PROTEIN STRUCTURE AND MOLECULAR ENZYMOLOGY, 1994, 1209 (02) :149-164
[7]   QUENCHING OF TRIPLET BENZOPHENONE BY VITAMIN-E AND VITAMIN-C AND BY SULFUR-CONTAINING AMINO-ACIDS AND PEPTIDES [J].
ENCINAS, MV ;
LISSI, EA ;
OLEA, AF .
PHOTOCHEMISTRY AND PHOTOBIOLOGY, 1985, 42 (04) :347-352
[8]   ABSOLUTE KINETICS OF HYDROGEN ABSTRACTION FROM ALPHA-TOCOPHEROL BY SEVERAL REACTIVE SPECIES INCLUDING AN ALKYL RADICAL [J].
EVANS, C ;
SCAIANO, JC ;
INGOLD, KU .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1992, 114 (12) :4589-4593
[9]   Increased antioxidant reactivity of vitamin C at low pH in model membranes [J].
Gramlich, G ;
Zhang, JY ;
Nau, WM .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2002, 124 (38) :11252-11253
[10]   Diffusion of α-tocopherol in membrane models:: Probing the kinetics of vitamin E antioxidant action by fluorescence in real time [J].
Gramlich, G ;
Zhang, JY ;
Nau, WM .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2004, 126 (17) :5482-5492