- Fluorescence sensor performance of a new fluorescein derivate: [2-morpholine-4-(6-chlorine-1,3,5-s-triazine)-amino]fluorescein
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A novel reactive fluorescent dye [2-morpholine-4-(6-chlorine-1,3,5-s-triazine)-amino]fluorescein based on 5-aminofluorescein was synthesized by electrophilic substitution. The photophysical properties, solvent effect, pH value sensitivity, and metal ions responsibility of this new fluorophore were investigated. Compared with 5-aminofluorescein, the novel fluorophore exhibited stronger fluorescence and longer lifetime. The fluorescence property of the new dye was obviously affected by different solvents and pH values, and it showed stronger fluorescence in the protic solvents or an alkaline environment. Moreover, the fluorescent intensity could be enhanced by the formation of complex with metal ions especially with Mg2+. The results show that the fluorescent dye is a promising efficient sensor for solvents, protons, and metal ions.
- Ge, Fengyan,Yang, Chun,Cai, Zaisheng
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- Preparation process of 5-aminofluorescein
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The invention relates to a preparation process of 5-aminofluorescein. The preparation process comprises the following steps: respectively adding 5-nitrofluorescein, a reducing agent and a solvent into a three-necked flask, conducting stirring and reacting for quantitative time under the condition of high temperature, cooling reaction liquid to room temperature, adding acid to adjust the acid-base property of a system, performing stirring and reacting for quantitative time under the condition of high temperature, then cooling the reaction solution to room temperature, filtering out insoluble substances, recrystallizing the insoluble substances twice with a dilute acid solution, finally dissolving the insoluble substances with a sodium hydroxide solution, adding acid for acidification, and carrying out drying to obtain the 5-aminofluorescein. The process is high in yield, mild in reaction conditions and simple in preparation process; a product with relatively high purity can be obtained without passing through a silica gel column, the product can be directly put into next-step reaction, and raw materials are low in price and common; and the process is very suitable for mass production.
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Paragraph 0030-0048
(2021/09/29)
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- Preparation method of fluorescein probe with specific selectivity
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The invention relates to the field of preparation of fluorescein probes with specific selectivity, and particularly discloses a preparation method of a fluorescein probe with specific selectivity. The method comprises the following steps: (1) mixing 4-nitrophthalic anhydride, resorcinol, nitrocyclohexane and anhydrous cobalt chloride, conducting heating and melting, adding zinc chloride, conducting reacting, then adding hydrochloric acid for reflux, and conducting filtering, washing and drying; (2) mixing a reducing solution containing Na2S and Na2SO3 with a product obtained in the step (1), conducting reacting, then dropwise adding glacial acetic acid until complete precipitation, and conducting filtering, washing and drying; and (3) mixing a mixed solvent containing methanol and triethylamine with a product obtained in the step (2), dropwise adding CS2, conducting reacting, dropwise adding a copper chloride aqueous solution, continuing reacting after dropwise adding, adjusting the pH value of the system to 1-2 by using hydrochloric acid, and carrying out reduced pressure distillation, washing, drying and column chromatography purification. According to the method, the conversion rate and the yield of the 5-fluorescein isothiocyanate are greatly improved.
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Paragraph 0039-0040; 0043; 0045; 0048; 0050; 0053; 0055
(2021/05/29)
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- Fluorescent human EP3 receptor antagonists
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Exchange of the lipophilc part of ortho-substituted cinnamic acid lead structures with different small molecule fluorophoric moieties via a dimethylene spacer resulted in hEP3R ligands with affinities in the nanomolar concentration range. Synthesized compounds emit fluorescence in the blue, green, and red range of light and have been tested concerning their potential as a pharmacological tool. hEP3Rs were visualized by confocal laser scanning microscopy on HT-29 cells, on murine kidney tissues, and on human brain tissues and functionally were characterized as antagonists on human platelets. Inhibition of PGE2 and collagen-induced platelet aggregation was measured after preincubation with novel hEP3R ligands. The pyryllium-labeled ligand 8 has been shown as one of the most promising structures, displaying a useful fluorescence and highly affine hEP3R antagonists.
- Tomasch, Miriam,Schwed, J. Stephan,Kuczka, Karina,Meyer Dos Santos, Sascha,Harder, Sebastian,Nuesing, Rolf M.,Paulke, Alexander,Stark, Holger
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supporting information
p. 774 - 779
(2012/11/13)
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- Nucleotides: Part LXXI. A new type of labelling of nucleosides and nucleotides
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A new labelling technique attaching fluorescein via a carbamoyl linker directly to the amino groups of the nucleobases was developed. The amino groups were first converted to the phenoxycarbonyl derivatives (→ 10, 15, 19, 58), which reacted under mild conditions with 5-aminofluorescein to give the corresponding N-[(fluorescein-5-ylamino)carbonyl] derivatives (→ 11-14, 16, 17, 20, 59, 60). The introduction of the 5-aminofluorescein residue into properly protected adenylyl-adenosine dimers (→ 39, 40) and trimer (→ 50) worked well, and final deprotection of these uniformly blocked precursors led on treatment with DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), in one step to dimer 41 and trimer 51. Synthesis of an appropriately protected monomeric phosphoramidite building block (→ 75) was more difficult, since introduction of the 2-(4-nitrophenyl) ethyl residue into the fluorescein moiety in 59 led mainly to trisubstitution to give 61 including the urea function. Formation of the adenylyl dimer 66 and trimer 67 proceeded in the usual manner by phosphoramidite chemistry; however, deprotection of 67 with DBU was incomplete since the O-alkyl group at the urea moiety was found to be very stable. Finally, the appropriate phosphoramidite building block 75 could be synthesized by the sequence 59 → 72 → 73 → 74 → 75. The phosphoramidite 75 was used for the synthesis of dimer 77 and trimer 79 by solution chemistry, as well as for that of various oligonucleotides by the machine-aided approach on solid support carrying the fluorophore at different positions of the chain (→ 84-87). The attachment of the fluorescein fluorophor via a short carbamoyl linker onto the 6-amino group of 2′-deoxyadenosine enables such molecules to function very well in fluorescence-polarization experiments.
- Sigmund, Harald,Pfleiderer, Wolfgang
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p. 2299 - 2334
(2007/10/03)
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- MICROWAVE ACTIVATION OF HETEROCYCLIZATIONS INVOLVING CARBOXYLIC ACIDS
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In the microvawe activation mode the duration of the synthesis of 2-phenylbenzimidazole, 2-phenylbenzoxazole, and also a number of xanthene dyes was reduced to several minutes.
- El'tsov, A. V.,Martynova, V. P.,Sokolova, N. B.,Dmitrieva, N. M.,Brykov, A. S
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p. 454 - 456
(2007/10/03)
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