Cr3+比色荧光探针的合成及细胞成像应用

以2,3,3-三甲基-3H-苯并[e]吲哚和对二甲氨基苯甲醛为原料, 乙醇作溶剂, 在酸性催化条件下, 通过一步反应合成了比色荧光探针B. 在EtOH/HEPES(pH=7.4)体积比为9∶1的混合体系中, 向探针B溶液中加入Cr ³⁺后, 溶液颜色由淡黄色变为紫红色, 说明探针B可以对Cr ³⁺进行裸眼识别. 紫外-可见吸收光谱和荧光发射光谱分析表明, 探针B对Cr ³⁺的选择性好、 灵敏度高且对EDTA有良好的接力识别. 探针B对Cr ³⁺的结合常数K_a=0.28×10 ² mol/L, 检出限为1.90×10 ^-8 mol/L, 该检出限低于世界卫生组织(WHO)规定的饮用水中Cr ³⁺的最大含量(9.60×10 ^-8 mol/L). 利用荧光发射光谱对实际水样中Cr ³⁺的浓度进行了定量检测. 探针B也可应用于对活细胞中Cr ³⁺的检测, 具有较好的应用前景和实用价值.     

罗丹明类阳离子荧光探针研究进展*

罗丹明类荧光染料由于具有摩尔消光系数高、光稳定性好、荧光量子产率高、较长的激发波长和发射波长等优异的光物理和光化学性能,现已成为制备荧光探针的一种理想材料之一。本文综述了近5年来基于螺酰胺环“关-开”机理和荧光共振能量转移（FRET）机理的罗丹明类Cu²⁺、Hg²⁺、Fe³⁺、Cr³⁺等荧光探针的设计合成、性能及其在阳离子分析方面的研究。介绍了具有良好细胞膜渗透性以及对细胞无毒副作用的罗丹明类阳离子荧光探针在活体或活细胞中应用研究的最新进展。并展望了这类荧光探针的发展趋势与应用前景。     

罗丹明类钯离子荧光分子探针

将烯丙基结构引入到罗丹明螺环中, 合成了荧光增强型钯离子探针RPd4. RPd4表现出对Pd²⁺的专一选择性和对其它阳离子良好的抗干扰能力. 探针荧光强度随着Pd²⁺的加入逐渐增强, 并且在微摩尔级呈现良好的线性关系, 通过拟合计算得到对Pd²⁺的检出限为0.51 μmol/L. RPd4具有较低的pK_a值(3.81±0.02), 说明该探针可以在近中性pH范围内对Pd²⁺进行选择性识别. 该探针还可以提供比色及荧光两种方式对Pd²⁺进行可视化检测.     

基于1,8-萘酰亚胺与罗丹明B间荧光共振能量转移的高选择性Hg2+比率荧光探针

以罗丹明B与1,8-萘二甲酰亚胺反应合成了1个高选择性Hg²⁺比率荧光探针(RN). 在甲醇/乙腈/4-羟基哌嗪乙磺酸缓冲溶液(pH=7.2, 体积比8:1:1)中, RN对Hg²⁺具有比色和比率荧光双重响应. 加入Hg²⁺后, RN的紫外-可见光谱在约556 nm处产生强吸收, 溶液由浅绿色变为橙色, 其它金属离子对RN的紫外-可见光谱几乎无影响. 无Hg²⁺存在时, RN的荧光光谱在540 nm处出现萘二甲酰亚胺荧光团的特征峰; 加入Hg²⁺后, 540 nm处的发射带逐渐消失, 同时在580 nm附近产生强荧光, 荧光颜色从绿色变为橙色. 这归因于从萘酰亚胺到开环罗丹明B的荧光共振能量转移(FRET), 探针RN对Hg²⁺的比率荧光响应具有高选择性, 不受其它共存金属离子的干扰.     

喹啉取代的氟硼二吡咯染料类三价铁离子荧光探针的合成与性能

设计合成了喹啉取代的氟硼二吡咯荧光探针(BHQ),并用核磁共振波谱仪(NMR)和高分辨质谱仪(HRMS)等技术手段对合成的化合物进行了表征。 结果表明,在水溶液中,探针BHQ在Fe³⁺存在下具有良好的荧光增强识别效果,对 Fe³⁺ 具有响应快、较好的灵敏度和选择性特点,而其它金属离子的存在不干扰 Fe³⁺ 的检测。 探针BHQ与Fe³⁺以摩尔比1:1的方式进行配位。 该探针在Fe³⁺的检测方面具有潜在的应用价值。     

新型2-吡啶苄基胺类罗丹明基活性小分子探针的合成

以罗丹明B和乙二胺为原料,通过缩合反应制得罗丹明酰乙二胺(1, Rhb);然后以无水THF作溶剂,化合物1与三聚氯嗪发生亲核取代反应,得到罗丹明酰乙二胺-三聚氯嗪化合物(2, Rhbc);最后在氮气氛围下,化合物2与N,N-二甲基吡啶胺反应合成了目标产物双(2 吡啶苄基) 胺罗丹明基小分子探针(3, Rhbd),其结构经¹H NMR、 IR、 HR-MS和元素分析表征。该探针可以识别Fe³⁺,检出限为30 nM。     

新型荧光探针罗丹明肉桂酰胺的合成及其用于荧光分光光度法测定汞

以罗丹明B和肉桂酸为主要反应物,制备了新型荧光探针罗丹明肉桂酰胺,并采用红外光谱、核磁和质谱对荧光探针的结构进行了表征。在含30%（φ）乙醇的pH 7.0 HEPES缓冲溶液中,荧光探针与Hg²⁺形成1比1的络合物,通过测定在发射波长584 nm处的荧光强度,与汞的浓度在1.0×10^-6mol·L^-1以内呈线性关系,方法的检出限（3s）为7.4×10^-9mol·L^-1。试验结果表明:该荧光探针对Hg²⁺具有很好的选择性,不受其他金属离子的干扰。     

细胞内铜离子的双光子荧光成像

基于无荧光的螺环结构与具有荧光的开环酰胺的平衡反应,本文合成了一个能在水基的缓冲溶液中选择性地识别Cu²⁺的罗丹明衍生物FD2.当在HEPES缓冲溶液中加入10当量的Cu²⁺时,FD2的单光子激发荧光和双光子激发荧光的强度均表现出明显的增强;更为重要的是,运用双光子荧光显微技术可以选择性地对活细胞内Cu²⁺进行成像.     

一种罗丹明6G类“Off-On”型Fe3+比色荧光探针

设计合成了一种基于罗丹明6G的新型比色荧光探针(RG),并通过核磁共振氢谱、碳谱和质谱进行了表征。该探针在pH=6的Tris-HCl缓冲溶液中可与Fe³⁺作用,溶液由无色变为粉红色,在530nm处产生强吸收,同时在557nm处发射强荧光。通过金属离子选择性实验,发现探针RG对Fe³⁺有高选择性;此外,探针溶液530nm的吸光度和557nm的荧光强度与Fe³⁺浓度呈良好的线性关系,检出限分别为1.26和3.87μmol/L。Job’s曲线分析表明探针分子与Fe³⁺的反应摩尔比为1∶1。此外,以乙二胺四乙酸为络合剂实现了探针分子的重复使用。该探针可用于实际水样中Fe³⁺的精准检测。     

多枝罗丹明酰肼类荧光探针的研究进展与应用

罗丹明以其良好的光稳定性、光物理性质和荧光效应得到了人们的极大重视。 基于罗丹明的螺环衍生物与被检测物质作用开环而产生荧光响应的特性,将两个或多个罗丹明母体单元构筑到包含特异性的识别单元的探针分子中,形成多枝的罗丹明酰肼类荧光探针,不仅可以弥补单分子探针的某些功能缺陷,而且可以使其具有更高灵敏度、更高选择性和可靠性,更加有利于分析检测。 本文着重从设计原理、识别性能、应用范围等方面介绍了多枝罗丹明探针在Hg2+、Cu2+、Fe3+和Al3+等离子检测中发展趋势,并展望了这类荧光探针在活细胞金属离子光学成像的应用前景。     

A new Cu~(2+)-induced color reaction of a rhodamine derivative N-(3-carboxy)acryloyl rhodamine B hydrazide

A new rhodamine derivative,N-(3-carboxy)acryloyl rhodamine B hydrazide(CARB),has been synthesized,and its unusual spectroscopic reaction with Cu2+ has been investigated.The derivative exhibits a rapid and reversible non-fluorescent absorption upon coordination to Cu2+,which is a rather unusual phenomenon for rhodamine B derivatives.Stoichiometric measurements using the Job's method and the molar ratio method reveal that one CARB molecule combines two Cu2+ ions,and the two Cu2+ ions play different roles:one ...     

New fluorescent and colorimetric chemosensors based on the rhodamine and boronic acid groups for the detection of Hg

Novel rhodamine B (RB) derivatives bearing mono and bis-boronic acid groups were investigated as Hg²⁺ selective fluorescent and colorimetric sensors. These derivatives are first examples of reversible fluorescent chemosensors for Hg²⁺ which utilized boronic acid groups as binding sites. Two new RB-boronic acid derivatives displayed selective ‘Off-On’-type fluorescent enhancements and distinct color changes with Hg²⁺. Selective fluorescent enhancement of two rhodamine derivatives was attributed to ring opening from the spirolactam (nonfluorescent) to ring-opened amide (fluorescent).     

Coumarin Modified Rhodamine Derivative： Fluorescent Chemosensor Selectively Recognizing Al^3＋ and Ca^2＋

A fluorescent probe with a coumarin moiety bound to rhodamine 6G hydrazide（l） was synthesized. Its sensing behavior toward various metal ions was investigated with fluorescence methods. Compound I displays different fluorescence emission responses to Al^3＋ and Ca^2＋ at the same excitation wavelength in the visible light region, while no changes occur after the addition of other metal ions. The binding ratios of the complexs of 1-Al^3＋ and 1-Ca^2＋ are both 2：1 according to the Job plot and high resolution mass spectrometer（HRMS） experiments. Moreover, emission spectrum of 1-Ca^2＋ complex and absorption spectrum of the rbodamine dyes overlap largely. When Al^3＋ was added to the 1-Ca2＋ system, calcium in complex 1-Ca2＋ can be displaced by Al^3＋, resulting in the output of another ratiometric sensing signal, which demonstrates that the 1-Ca^2＋ complex can be served as a new and effective fluorescence resonance energy transfer（FRET） donor for rhodamine derivatives.     

Rhodamine 101 Conjugates of Triterpenoic Amides Are of Comparable Cytotoxicity as Their Rhodamine B Analogs

Pentacyclic triterpenoic acids (betulinic, oleanolic, ursolic, and platanic acid) were selected and subjected to acetylation followed by the formation of amides derived from either piperazine or homopiperazine. These amides were coupled with either rhodamine B or rhodamine 101. All of these compounds were screened for their cytotoxic activity in SRB assays. As a result, the cytotoxicity of the parent acids was low but increased slightly upon their acetylation while a significant increase in cytotoxicity was observed for piperazinyl and homopiperazinyl amides. A tremendous improvement in cytotoxicity was observed; however, for the rhodamine B and rhodamine 101 conjugates, and compound 27, an ursolic acid derived homopiperazinyl amide holding a rhodamine 101 residue showed an EC₅₀ = 0.05 µM for A2780 ovarian cancer cells while being less cytotoxic for non-malignant fibroblasts. To date, the rhodamine 101 derivatives presented here are the first examples of triterpene derivatives holding a rhodamine residue different from rhodamine B.     

Selective Detection of Hg2+ Ions with Boron Dipyrromethene‐Based Fluorescent Probes Appended with a Bis(1,2,3‐triazole)amino Receptor

By using a copper‐promoted alkyne–azide cycloaddition reaction, two boron dipyrromethene (BODIPY) derivatives bearing a bis(1,2,3‐triazole)amino receptor at the meso position were prepared and characterized. For the analogue with two terminal triethylene glycol chains, the fluorescence emission at 509 nm responded selectively toward Hg²⁺ ions, which greatly increased the fluorescence quantum yield from 0.003 to 0.25 as a result of inhibition of the photoinduced electron transfer (PET) process. By introducing two additional rhodamine moieties at the termini, the resulting conjugate could also detect Hg²⁺ ions in a highly selective manner. Upon excitation at the BODIPY core, the fluorescence emission of rhodamine at 580 nm was observed and the intensity increased substantially upon addition of Hg²⁺ ions due to inhibition of the PET process followed by highly efficient fluorescence resonance energy transfer (FRET) from the BODIPY core to the rhodamine moieties. The Hg²⁺‐responsive fluorescence change of these two probes could be easily seen with the naked eye. The binding stoichiometry between the probes and Hg²⁺ ions in CH₃CN was determined to be 1:2 by Job′s plot analysis and ¹H NMR titration, and the binding constants were found to be (1.2±0.1)×10¹¹ m ^?2 and (1.3±0.3)×10¹⁰ m ^?2, respectively. The overall results suggest that these two BODIPY derivatives can serve as highly selective fluorescent probes for Hg²⁺ ions. The rhodamine derivative makes use of a combined PET‐FRET sensing mechanism which can greatly increase the sensitivity of detection.     

具有荧光增强性能的罗丹明B衍生物的合成及其对汞离子的检测

利用汞离子可以诱导罗丹明B衍生物的螺环结构发生开环反应并产生荧光增强效果这一特性,设计并合成了两种新型的荧光化学传感器2-噻吩甲醛罗丹明B酰肼(RhBTh)和苯甲醛罗丹明B酰肼(RhBAr),并研究了二者在汞离子检测中的应用.研究结果表明,RhBTh与RhBAr对汞离子均表现出非常好的荧光增强效果,检测过程中其它金属离子不会对检测结果产生明显的干扰.二者对汞离子的检测限分别为7.8 nmol/L和12.5 nmol/L.实验表明RhBTh和RhBAr对汞离子均具有良好的灵敏度和选择性.     

Bis-ratiometric absorbance detection of Al(III) in the rhodamine B-functionalized bis-polydiacetylene film

A rhodamine B-functionalized bis-polydiacetylene (RB/bis-PDA) film sensor was prepared. Rhodamine B derivatives as the ion-recognition elements were embedded in the bis-polydiacetylene matrix through the hydrolysis/condensation process of organic silicon. The as-prepared blue-phase RB/bis-PDA film could transfer to yellow phase at high temperatures. Upon dipping the blue and yellow RB/bis-PDA films into various metal ion solutions, respectively, only Al³⁺ could induce remarkable changes in absorption and color signals. The UV–Vis absorption spectrum of the Al³⁺-containing film showed two separate absorption peaks at 556 nm and at another wavelength (617 or 470 nm), corresponding to ring opening of the spirolactam structure in rhodamine moiety and PDA (blue- or yellow-phase PDA), respectively. Utilizing the different intensity ratios of the two absorption signals (A₅₅₆/A₆₁₇ or A₅₅₆/A₄₇₀), the RB/bis-PDA system could be used as a bis-ratiometric absorbance sensor for Al³⁺. The reusable and free-standing films have great potential in environmental and biological sensing fields as they are more convenient to achieve real-time sensing than the conventional probes dissolved in aqueous or organic solvents.     

Facile Synthesis of 5‐Benzylidene Rhodamine Derivatives under Microwave Irradiation

A series of 5‐benzylidenerhodamine derivatives were synthesized by the cross‐aldol condensation of an aromatic aldehyde with rhodamine or rhodamine acetic acid in sodium acetate/acetic acid under microwave irradiation. The reaction was completed in 8–20 min with 63–94% yields and was environmentally benign with easy workup.     

若丹明类荧光探针的合成与应用研究进展

本文综述了近年来若丹明类荧光染料的研究状况.首先,介绍了若丹明衍生物的结构特征,然后以其修饰位置为线索,详细地介绍了该类化合物的合成,总结了其修饰策略及结构与功能之间的联系,强调了它们在环境分析和生物标记领域的应用.以供读者了解若丹明荧光探针的合成及其在蛋白质、DNA等生物标记领域和金属离子检测领域的应用时参考.     

Synthesis of heterocyclic substituted norcantharidin derivatives

Twenty novel norcantharidin derivatives, which were substituted by thiazole ring, were synthesized in a single step by the [3+2] 1,3‐dipolar cycloaddition reaction with oxime or hydrazone in the presence of chloramine‐T when compared with the conventional method. J. Heterocyclic Chem., (2011).