Near-infrared fluorescent probe and application thereof in detection of glutathione thiotransferase

Abstract

The invention relates to a near-infrared fluorescent probe with obviously enhanced fluorescence intensity in the presence of glutathione thiotransferase. The structure of the fluorescent probe is shown in the specification, wherein R1, R2, R5, R6 and R7 are H, alkyl, aryl or substituent groups containing heteroatoms, and R3 and R4 are O or N atoms. The fluorescent probe can be used for near-infrared excitation and can emit near-infrared fluorescence to detect glutathione thiotransferase. The fluorescent probe is advantaged in that an optimized nitrobenzene structure is introduced into a fluorescent parent with near-infrared absorption and luminescence properties as an active center for recognition and reaction with glutathione thiotransferase, near-infrared fluorescence detection of the glutathione thiotransferase is realized by utilizing fluorescence intensity difference between reactant and a product, and penetrability and a signal-to-noise ratio are enhanced and practicability is improved as the emitted fluorescence further belongs to a near-infrared band.

Description

Technical field: [0001] The invention relates to the field of fluorescent probes, in particular to a class of near-infrared fluorescent probes and their application in detecting glutathione sulfur transferase. Background technique: [0002] Glutathione sulfur transferase (GST) is a multifunctional protein, one of the most important functions of which is to act as a phase II detoxification enzyme and widely exists in prokaryotes and eukaryotes. It is mainly divided into three types, namely cytoplasmic type, mitochondrial type and microsome type, among which cytoplasmic GST includes a variety of isozymes. There are seven types of cytoplasmic GST in the human body—α, μ, π, σ, θ, ζ, ω—among which α, μ, and π are the most important three, namely GSTA, GSTM, and GSTP. GST can catalyze the nucleophilic addition reaction of glutathione (GSH) to exogenous substances and endogenous electrophiles, and the resulting adducts are then excreted through the glutathione complex transporter,...

AI Technical Summary

Problems solved by technology

Thereby Ralf Morgenstern etc. disclose a kind of near-infrared fluorescent probe DNs-CV that is used to detect various GST isozymes (structure see figure 1 , Ralf Morgenstern et al., J.Am.Chem.Soc., 2011,133,14109), however, the probe can still undergo a certain degree of non-enzymatic reaction with GSH without the catalysis of GST to produce a large background noise

[0004] We have recently developed a class of two-photon fluorescent probes using naphthalimide as the fluorescent matrix. However, although this fluorescent probe has high sensitivity and signal-to-noise ratio, the fluorescence produced during the detection process is not sufficient. It belongs to the near-infrared band, which leads to its unsatisfactory biological penetration and is difficult to be used for in vivo imaging. Therefore, it is necessary to develop a high-sensitivity and signal-to-noise ratio, which has both near-infrared excitation and near-infrared fluorescence, and can be used in in vitro water environments and biological Fluorescent probes for the detection of various GST isoenzymes in samples such as living tumors are of great significance

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