Res. Chem. Intermed.
, Vol. 32, No. 1, pp. 43–57 (2006)
VSP 2006.
Also available online - www.vsppub.com
A novel 1,8-naphthalimide probe: synthesis and
interactions with nucleic acid and its precursor
HE-TING LI
1
, ZHI-QIN JIANG
1,∗
, JUAN ZHENG
1
, XIN WANG
1
,
YANG PAN
2
, FENG WANG
2
and SHU-QIN YU
2
1
Department of Chemistry, Tongji University, Shanghai 200092, P. R. China
2
Department of Chemical Physics, University of Science and Technology of China,
Hefei 230026, P. R. China
Received 21 April 2004; accepted 7 January 2005
Abstract—Three novel, water-soluble N-substituted 1,8-naphthalimides as the spectroscopic probes
of nucleic acid, N-(2-hydroxyethyl)-1,8-naphthalimide (NI1), 1,8-naphthalimide-N-acetic acid (NI2)
and 1,8-naphthalimide-N-caproic acid (NI3), were synthesized and photophysically characterized.
The steady-state fluorescence quenching of the NI probes with nucleic acids (NA) and their precursors
(nucleobases and nucleosides) were studied by Stern–Volmer correlation. The rate constants for
bimolecular quenching were obtained in Tris buffer solution. The transient absorption spectroscopy
by nanosecond laser flash photolysis were explored to identify the transient species and to determine
the kinetics. The dynamic interaction mechanism was attributed to electron transfer (ET) and energy
transfer via
3
NI.
Keywords: 1,8-Naphthalimides; electron transfer; interaction; kinetics.
INTRODUCTION
Fluorescent probes are efficient and powerful tools and are extensively used in
molecular biology, especially in the studies of nucleic acids (NA) and thier
precursors (nucleobases, nucleosides and nucleotides), such as hybridization, DNA
sequencing, nucleic acid–protein interaction, applications of DNA in medical
diagnosis and damage of DNA, etc. [1].
Naphthalenimides are useful molecule probes, not only because they have unique
luminescence and transient properties, but also because they have merits to demon-
strate a diversity of reactivity towards biological substrates including DNA and
proteins [2]. In addition, 1,8-naphthalimide derivatives acting as guanine-specific
∗
To whom correspondence should be addressed. Department of Chemistry, Tongji University,
Shanghai 200092, P. R. China. E-mail: zqjiang@mail.tongji.edu.cn