基于香豆素的比率荧光传感器对同型半胱氨酸/半胱氨酸的检测及生物成像（英文）

利用生物硫醇独特的亲核性,报道了基于香豆素的荧光传感器C1和C2,可实现对半胱氨酸和同型半胱氨酸的检测.化合物C1对Hcy/Cys表现出明显的荧光增强响应.通过结构的微调,设计并合成了比率荧光传感器C2.在化合物C2的溶液中加入Hcy/Cys之后,溶液的最大发射峰蓝移了近100 nm,最大吸收光谱蓝移了近95 nm.传感器C2具有较高的选择性,对Hcy的响应远远大于对Cys、GSH及其他氨基酸的响应.传感器C2对Hcy有较高的灵敏度,检出限低达2.8×10~(-7)mol/L.并且,化合物C2可以穿透细胞膜,用于HeLa细胞中Hcy的比率荧光成像.     

特异性识别半胱氨酸荧光探针的合成及细胞成像研究

基于光诱导电子转移(PET)机制,利用Cys亲核性较强,能够与探针分子发生亲核取代反应,使丙烯酰基离去,使探针分子体系内PET过程失效,合成了一种特异性识别半胱氨酸的荧光探针。当向探针溶液分别加入多种测试物时,除与Cys结构类似的Hcy和GSH会引起探针溶液微弱的荧光变化外,其他氨基酸均不会引起探针溶液荧光强度的变化,该探针对Cys具有良好的选择性和灵敏度,可在生理条件下检测Cys,并且区分Hcy和GSH。同时,该探针成功实现了细胞内Cys的荧光成像,为在生物学及医学中的实际应用建立了一种特异性识别Cys的分析方法。     

一种基于硝基烯烃的硫醇荧光探针的合成及生物成像研究

生命体内小分子硫醇,如半胱氨酸(Cys)、同型半胱氨酸(Hcy)和谷胱甘肽(GSH),在多种生理和病理过程中发挥重要作用.以氟硼二吡咯(BODIPY)为荧光团,硝基烯烃为识别基团,经三步简单有机合成,构建了一个打开型硫醇荧光探针.密度泛函理论计算结果表明,硝基通过光诱导电子转移(PET)机制淬灭BODIPY荧光.光谱测试结果表明,探针与硫醇发生迈克尔加成反应,响应迅速,选择性好,灵敏度高,对GSH的检测极限低至11×10~(-9) mol/L.荧光共聚焦成像结果表明,探针可用于HeLa细胞和斑马鱼内源生物硫醇荧光成像研究.     

一种“硫醇-色烯点击反应”的荧光探针的合成及应用

本文设计合成了一种基于硫醇-色烯点击反应的荧光探针CHMPC-Ac,用于半胱氨酸(Cys)、同型半胱氨酸(Hcy)和谷胱甘肽(GSH)的识别检测.这些生物硫醇因巯基的强亲核性而与探针的不饱和酮发生迈克尔加成反应,导致色烯分子开环等分子内级联反应,生成具有强荧光的香豆素衍生物,分别使荧光强度增强107、69和66倍. CHMPC-Ac具有灵敏度高(Cys:15 nM; Hcy:26 nM; GSH:22 nM)和响应快(Cys:20 s; Hcy:50 s; GSH:30 s)等优点,并已应用于HepG 2细胞和斑马鱼体内生物硫醇的识别检测.     

5-马来酰亚胺-2-(间马来酰亚胺基苯基)苯并噁唑用于荧光光度法直接测定还原型谷胱甘肽的研究

以5-马来酰亚胺-2-(间马来酰亚胺基苯基)苯并噁唑(DMPB)为荧光试剂,建立了在一定量半胱氨酸(Cys)存在下荧光光度法直接测定还原型谷胱甘肽(GSH)的新方法。研究表明,DMPB荧光很弱,其结构中的两个马来酰亚胺基团都能与GSH或Cys发生反应,生成具有强荧光的产物。并且DMPB与GSH或Cys的生成物(分别称为DMPB-GSH和DMPB-Cys)的最大荧光波长会以不同的速率从eλx/eλm=302/372nm红移至eλx/eλm=310/430 nm,最终均在eλx/eλm=310/430 nm处稳定。在pH 7.0的Na2HPO4-KH2PO4缓冲溶液中和35℃下,DMPB与GSH或Cys反应15 min后,生成的DMPB-GSH的最大荧光波长为eλx/eλm=302/372 nm,且最大荧光强度可以稳定1h,而DMPB-Cys的最大荧光波长为eλx/eλm=310/430 nm,且荧光较弱。利用这一差别,我们选择在eλx/eλm=302/372 nm的荧光波长下测定GSH,完成了0.3倍(Cys∶GSH,摩尔比)Cys存在下对GSH的直接测定,方法线性范围为4.0×10-8~9.6×10-7mol.L-1,检出限(S/N=3)为1.5×10-9mol.L-1。用该法测定了人全血中的GSH,结果令人满意。     

基于“芳香亲核取代-重排”机理检测生物活性分子的荧光探针

生物硫醇包括谷胱甘肽(GSH)、半胱氨酸(Cys)和同型半胱氨酸(Hcy),在生理过程中扮演着不同的重要角色,其分布和浓度的异常变化常与多种疾病的病理过程息息相关.由于生物硫醇结构和反应活性的相似性,对它们的选择性检测极具挑战.近年来,“芳香亲核取代-重排”机理发展成为生物硫醇选择性检测的通用策略,并扩展到其他生物活性分子的检测.本文根据探针荧光团和检测物的不同进行分类,综述了基于“芳香亲核取代-重排”机理的荧光探针的设计、合成与应用进展.     

选择性生物小分子硫醇荧光探针的研究进展

谷胱甘肽(GSH)、半胱氨酸(Cys)和高半胱氨酸(Hcy)作为生物体内含量较高的生物硫醇,在生物系统中起着重要作用。近年来,生物与环境样品中小分子生物硫醇的检测引起科学家们极大的兴趣,生物硫醇荧光探针和比色传感器得到快速发展。同时,作为更加精确的检测手段,选择性生物硫醇荧光探针的研究也得到了极大的关注。本文根据选择性生物硫醇荧光探针与生物硫醇的反应机理:醛基环化反应、丙烯酸酯加成环化反应、自然的化学连接反应、芳环取代重排反应和亲核加成-亲核取代反应,综述了近年来选择生物硫醇荧光探针的设计、合成与应用进展。     

基于分子内电荷转移机制的巯基荧光比色化学传感器

设计并合成了以香豆素为荧光发色团的多氰基分子化合物TCC。分子内强烈的电荷转移效应使得其本身荧光较弱。巯基化合物如半胱氨酸（Cys）、高半胱氨酸（Hcy）和还原型谷胱甘肽（GSH）的加入能与TCC中的三氰基乙烯基进行加成反应从而破坏分子内电荷转移,使分子内电荷转移吸收峰消失,颜色由紫色变成黄绿色,最大吸收波长由560 nm移至380 nm。并且化合物的荧光也随着巯基化合物的加入逐渐增强,荧光的强度与巯基化合物的浓度有很好的线性关系,检测限可以达到10^-5 mol/L。其它离子与不含巯基的氨基酸则不会与化合物TCC发生上述反应,也就不会对体系的吸收和荧光光谱产生明显的影响,从而实现高效、专一的识别巯基化合物。     

新型含双酚衍生物三枝氟硼二吡咯染料的合成及其光物理性能

以三聚氯氰为原料合成含醛基的二酚氧基取代中间体（1）; 1分别与酚衍生物（2a~2e）经取代反应制得三酚氧基中间体（3a~3e）; 3a~3e经缩合、氧化和配位等反应合成了5个新型的含双酚衍生物三枝氟硼二吡咯（BODIPY）荧光染料（4a~4e）,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。4a~4e的最大吸收波长和发射波长分别位于499 nm和508 nm,荧光量子产率为0.41~0.55,显示出BODIPY荧光核典型的光物理性能。     

氟硼二吡咯(BODIPY)荧光染料的合成研究进展

氟硼二吡咯(BODIPY)荧光染料因为具有优异的光物理性能、良好的生物相容性以及易于合成和修饰等优点,在生命科学、化学分析和光电材料等领域得到了广泛应用.丰富的合成及衍生策略为其广泛应用提供了基础,引起了研究者的极大关注.总结了BODIPY荧光染料不同反应位点的修饰策略,并单独介绍了基于BODIPY的Pd催化交叉偶联反应和氧化偶联反应,最后对该领域的发展进行了展望.     

Development of a Small Molecule Probe Capable of Discriminating Cysteine,Homocysteine, and Glutathione with Three Distinct Turn‐On Fluorescent Outputs

The simultaneous discrimination of Cys, Hcy, and GSH by a single probe is still an unmet challenge. The design and synthesis of a small molecule probe MeO‐BODIPY‐Cl (BODIPY=boron dipyrromethene) is presented, which can allow Cys, Hcy, and GSH to be simultaneously discriminated on the basis of three distinct fluorescence turn‐on responses. The probe reacts with these thiols to form sulfenyl‐substituted BODIPY, which is followed by intramolecular displacement to yield amino‐substituted BODIPY. The kinetic rate of the intramolecular displacement reaction determines the observed different sensing behavior. Therefore, the probe responds to Cys, Hcy, and GSH with fluorescence turn‐on colors of yellow, yellow and red, and red, respectively. With this promising feature in hand, the probe was successfully used in imaging of Cys, Hcy and GSH in living cells.     

α-Acrylaldehyde 3-Pyrrolyl BODIPY as a Specific Optical Sensor for Cysteine and Homocysteine

A new fluorophore, α-acrylaldehyde 3-pyrrolyl BODIPY was synthesized by treating 3-pyrrolyl BODIPY with a mixture of 3-(dimethylamino) acrolein and POCl₃ under Vilsmeier–Haack reaction conditions. The X-ray structure revealed that the fluorophore was almost planar, and the appended pyrrole was in the same plane with a small deviation from the mean plane. We investigated the potential use of α-acrylaldehyde 3-pyrrolyl BODIPY for sensing thiol containing amino acids such as cysteine/homocysteine (Cys/Hcy). Our studies showed that the α-acrylaldehyde- 3-pyrrolyl BODIPY was found to be useful for exclusive sensing of Cys/Hcy and to exhibit different optical signaling responses to Cys and Hcy at physiological pH in aq. CH₃CN (1 : 1 v/v, PBS) medium. The enhancement in optical properties for Cys and quenching in same properties for Hcy was attributed to different binding modes of Cys/Hcy with α-acrylaldehyde 3-pyrrolyl BODIPY.     

Design of fluorescent probes with optimized responsiveness and selectivity to GSH

We designed and synthesized a series of BODIPY based probes with fast and distinct ratiometric responsiveness for discriminative detection of GSH from Cys and Hcy. The discriminative detection is based on the different products obtained by the S_NAr between probes and thiol-containing amino acids. The amino group of the obtained thioether from the reaction with Cys or Hcy but not GSH would trigger an intramolecular nucleophilic substitution through five- or six-membered cyclic transition state, finally yielding an amino substituted derivative. To achieve highly discriminative detection and fast response, a series of structure modifications and improvements have been made by elongating the π-conjugation and introducing electron withdrawing groups, finally affording probe BOD-DBNPF with optimized responsiveness and selectivity. Importantly, BOD-DBNPF was successfully used for the selective detection of GSH from Cys with distinct fluorescent ratiometric responses in living HeLa cells.     

A multisite-binding fluorescent probe for simultaneous monitoring of mitochondrial homocysteine,cysteine and glutathione in live cells and zebrafish

Homocysteine(Hcy), cysteine(Cys) and glutathione(GSH) play crucial roles in redox homeostasis during mitochondria functions. Simultaneous differentiation and visualization of mitochondrial biothiols dynamics are significant for understanding cell metabolism and their related diseases. Herein, a multisitebinding fluorescent probe(MCP) was developed for simultaneous sensing of mitochondrial Cys, GSH and Hcy from three fluorescence channels for the first time. This novel probe exhibited rapid fluor...     

A colorimetric,ratiometric and water-soluble fluorescent probe for simultaneously sensing glutathione and cysteine/homocysteine

A chlorinated coumarin-aldehyde was developed as a colorimetric and ratiometric fluorescent probe for distinguishing glutathione (GSH), cystenine (Cys) and homocysteine (Hcy). The GSH-induced substitution-cyclization and Cys/Hcy-induced substitution-rearrangement cascades lead to the corresponding thiol-coumarin-iminium cation and amino-coumarin-aldehyde with distinct photophysical properties. The probe can be used to simultaneously detect GSH and Cys/Hcy by visual determination based on distinct different colors – red and pale-yellow in PBS buffer solution by two reaction sites. From the linear relationship of fluorescence intensity and biothiols concentrations, it was determined that the limits of detection for GSH, Hcy and Cys are 0.08, 0.09 and 0.18 μM, respectively. Furthermore, the probe was successfully used in living cell imaging with low cell toxicity.     

Rational design of a bifunctional fluorescent probe for distinguishing Hcy/Cys from GSH with ideal properties

By pairing two fluoropho res according to their optical prope rties such as absorption spectral overlap and absorptivity,fluorescent quantum yield and emission spectral separation,a bifunctional fluorescent probe,TQBF-NBD,was rationally designed and synthesized to discriminatively sense Hcy/Cys and GSH with good selectivity and sensitivity.It is noted that this probe could work under a single-wave length excitation and displayed a mega-large Stokes shift.TQBF-NBD reacted with Hcy/Cys to give a mixed green-red fluorescence and displayed a red fluorescence upon the treatment with GSH.Distinguishable imaging of intracellular Hcy/Cys from GSH with the help of TQBF-NBD was realized in living cells and zebrafish.     

BODIPY-Based Fluorescent Probes for Biothiols

Fluorescent probes for biothiols have aroused increasing interest owing to their potential to enable better understanding of the diverse physiological and pathological processes related to the biothiol species. BODIPY fluorophores exhibit excellent optical properties, which can be readily tailored by introducing diverse functional units at various positions of the BODIPY core. In the present review, the development of fluorescent probes based on BODIPYs for the detection of biothiols are systematically summarized, with emphasis on the preferable detection of individual biothiols, as well as simultaneous discrimination among cysteine (Cys), homocysteine (Hcy), reduced glutathione (GSH). In addition, organelle-targeting probes for biothiols are also highlighted. The general design principles, various recognition mechanisms, and biological applications are elaboratively discussed, which could provide a useful reference to researchers worldwide interested in this area.     

A Multi‐signal Fluorescent Probe with Multiple Binding Sites for Simultaneous Sensing of Cysteine,Homocysteine, and Glutathione

A novel fluorescent probe was developed by integrating chlorinated coumarin and benzothiazolylacetonitrile and exploited for simultaneous detection of cysteine (Cys), homocysteine (Hcy), and glutathione (GSH). Featuring four binding sites and different reaction mechanisms for different biothiols, this probe exhibited rapid fluorescence turn‐on for distinguishing Cys, Hcy, and GSH with 108‐, 128‐, 30‐fold fluorescence increases at 457, 559, 529 nm, respectively, across different excitation wavelengths. Furthermore, the probe was successfully applied to the fluorescence imaging of endogenous Cys and GSH and exogenous Cys, Hcy, and GSH in living cells.     

A Multi‐signal Fluorescent Probe with Multiple Binding Sites for Simultaneous Sensing of Cysteine,Homocysteine, and Glutathione

A novel fluorescent probe was developed by integrating chlorinated coumarin and benzothiazolylacetonitrile and exploited for simultaneous detection of cysteine (Cys), homocysteine (Hcy), and glutathione (GSH). Featuring four binding sites and different reaction mechanisms for different biothiols, this probe exhibited rapid fluorescence turn‐on for distinguishing Cys, Hcy, and GSH with 108‐, 128‐, 30‐fold fluorescence increases at 457, 559, 529 nm, respectively, across different excitation wavelengths. Furthermore, the probe was successfully applied to the fluorescence imaging of endogenous Cys and GSH and exogenous Cys, Hcy, and GSH in living cells.     

Benzothiazole‐Pyimidine‐Based BF2 Complex for Selective Detection of Cysteine

Due to the similar structure and reactivity of cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), the simultaneous discrimination of Cys over Hcy and GSH by a single fluorescent sensor is still a great challenge. In this work, a benzothiazole‐pyimidine‐based boron difluoride complex ( BPB ) was developed as a new fluorescent sensor for Cys. The sensor exhibits a highly selective “turn‐on” response to cysteine over Hcy, GSH and other amino acids in aqueous solution at physiological pH. The observed pseudo‐first‐order rate constant for the reaction of BPB with Cys was calculated to be about 0.062 min⁻¹. The detection limit of this sensor for Cys was determined to be 332 nm, and bioimaging of exogenous Cys by this sensor was successfully applied in living cells, thus indicating that this sensor holds great potential for biological applications.