Cysteine‐Specific Blue Fluorescence Probe

Abstract

A strong fluorescence probe has been designed to investigate cytochrome c folding kinetics. The cysteine specific modifier, 2-[(-Iodo-acetyl)-methyl-amino]-6-methylaminobenzoic acid methyl ester (1), has been prepared, and the reaction with cysteine can be performed in aqueous solution to ensure its application to protein modification. The model compound, 2-{[2-(2-Acetylamino-2-methyoxycarbonylethylsulfanyl)-acetyl]-methyl-amino}-6-methyl amino-benzoic acid methyl ester (2), resulting from the reaction of 1 with N-acetyl cysteine has emission quantum yields of 0.627 and 0.185 in nonaqueous and aqueous buffer solutions, respectively. The lifetime of 4.6 ns for compound 2 manifests a singlet excited-state. The Förster energy transfer distance of compound 2 and cytochrome c is calculated to be 45 Å.

A New Method for Synthesis of Thioethers from Phenyl N-Sulfonamide

“…In continuation of our ongoing work for the synthesis of 7-Aminomethyl phthalides based fluorescent for the study of Cysteine-Specific Blue Fluorescence Probe 13 , we developed a novel method for the synthesis of thioether 4 by a one-pot reaction by using the commercial available, trimethylsilyl iodide as a reagent in acetonitrile under reflux conditions, where it undergo multiple functional group changes, varies with mole equivalent of TMS-I used in the reaction Surprisingly, it gives regio selective product, thioether 4 by C-S bond formation in 30% yield.…”

“…Compounds described in the literature was characterized by comparing their 1 H and 13 3.70 (s, 3H), 2.32 (s, 3H). 13…”

A Convenient Synthesis and Spectral Studies of Diamines Derivatives

“…The authors thank the National Science Foundation and the Welch Foundation for support of this work. 27 2-azidocarbonyl-6-nitro-benzoic acid methyl ester (3), 28 2-amino-6-nitrobenzoic acid methyl ester (4), 29 2,6-diamino benzoic acid methyl ester (5), 30 2-Carbomethoxy-6nitro-benzoic acid (6), 31 2-carbomethoxy-6-nitro-benzoyl chloride(7), 32 2-azidocarbonyl-3-nitrobenzoic acid methyl ester(8), 33 2-amino-3-nitrobenzoic acid methyl ester (9), 30 2,3-diamino benzoic acid methyl ester (10), 34 were prepared with modified methods and spectral data is presented. -Benzyloximino acid chloride 22 and 1,3-dithiolane-2-carbonyl chloride 16 were prepared as described previously.…”

Green Synthesis: A Novel Method for Bromination of 7-AminoPhthalide

“…The results illustrate the potential utility of this method as an environment-friendly process with conserve the half mole equivalent of halide. The obtained products were useful in fluorescence probe study to modify the cysteine and its application to protein modifications 32 .…”