55738-75-5Relevant academic research and scientific papers
An efficient synthesis of 3-(N-piperidinemethyl)-2,2,5,5-tetramethyl-1-oxy-3-pyrroline, a promising radioprotector for cancer radiotherapy
Wu, Haitao,Coble, Vincent,Vasalatiy, Olga,Swenson, Rolf E.,Krishna, Murali C.,Mitchell, James B.
, p. 5570 - 5571 (2014)
Nitroxides can ameliorate the toxic effects of radiation during cancer therapy. Nitroxides are paramagnetic and can be used in magnetic resonance imaging (MRI) and electron paramagnetic resonance imaging (EPRI) to monitor in vivo oxidative stress status. Compound 5 (3-(N-piperidinemethyl)-2,2,5,5-tetramethyl-1-oxy-3-pyrroline) was found to be the most effective nitroxide radioprotector. An efficient synthesis for this promising radioprotector was developed.
Improvement of a critical intermediate step in the synthesis of a nitroxide-based spin-labeled deoxythymidine analog
Powell, Jeannine H.,Johnson II, Edward M.,Gannett, Peter M.
, p. 1244 - 1250 (2000)
Methods to reduce the carboxylic acid moiety in 3-carboxy-2,2,5,5- tetramethyl-pyrrolin-1-oxyl to an alcohol as an intermediate toward the corresponding aldehyde have been explored and an improved method has been developed.
Synthesis of Chiral Spin-Labeled Amino Acids
Vuong, Wayne,Mosquera-Guagua, Fabricio,Sanichar, Randy,McDonald, Tyler R.,Ernst, Oliver P.,Wang, Lei,Vederas, John C.
, p. 10149 - 10153 (2019/12/24)
Spin-labeled amino acids (SLAAs) are often used to determine intermolecular distances and conformations in proteins via double electron-electron resonance. Currently available SLAAs can be difficult to incorporate selectively and have little resemblance to natural side chains in proteins. Enantioselective synthesis of three spin-labeled l-amino acids is described, starting from readily available 2,2,6,6-tetramethyl-4-piperidinone. These SLAAs better replicate canonical residues in proteins and aim for biological incorporation via genetic incorporation or solid-phase peptide synthesis.
Synthesis and fluorescence properties of six fluorescein-nitroxide radical hybrid-compounds
Sato, Shingo,Endo, Susumu,Kurokawa, Yusuke,Yamaguchi, Masaki,Nagai, Akio,Ito, Tomohiro,Ogata, Tateaki
, p. 66 - 71 (2016/07/06)
Six fluorescein-nitroxide radical hybrid-compounds (2ab, 3ab, 4, and 5) were synthesized by the condensation of 5- or 6-carboxy-fluorescein and 4-amino-TEMPO (2ab), 5- or 6-aminofluorescein and 4-carboxy-TEMPO (3ab), and fluorescein and 4-carboxy-TEMPO (4), or by reaction of the 3-hydroxyl group of fluorescein with DPROXYL-3-ylmethyl methanesulfonate (5). Fluorescence intensities (around 520 nm) after reduction of the radical increased to 1.43-, 1.38-, and 1.61-folds for 2a, 2b and 3b respectively; 3a alone exhibited a decrease in intensity on reduction. Since 4 was readily solvolyzed in PBS or even methanol to afford fluorescein and 4-carboxy-TEMPO, its fluorescence change could not be measured. Hybrid compound 5 containing an ether-linkage between the fluorescein phenol and 3-hydroxymethyl-DPROXYL hydroxyl centers, was stable and on reduction, showed a maximum increase (3.21-fold) in relative fluorescence intensity in PBS (pH 5.0), despite its remarkably low absolute fluorescence intensity.
2′-Alkynylnucleotides: A Sequence- and Spin Label-Flexible Strategy for EPR Spectroscopy in DNA
Haugland, Marius M.,El-Sagheer, Afaf H.,Porter, Rachel J.,Pe?a, Javier,Brown, Tom,Anderson, Edward A.,Lovett, Janet E.
, p. 9069 - 9072 (2016/08/05)
Electron paramagnetic resonance (EPR) spectroscopy is a powerful method to elucidate molecular structure through the measurement of distances between conformationally well-defined spin labels. Here we report a sequence-flexible approach to the synthesis of double spin-labeled DNA duplexes, where 2′-alkynylnucleosides are incorporated at terminal and internal positions on complementary strands. Post-DNA synthesis copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions with a variety of spin labels enable the use of double electron-electron resonance experiments to measure a number of distances on the duplex, affording a high level of detailed structural information.
Synthesis of Next-Generation Maleimide Radical Labels
Hajjaj, Bouchra,Shah, Anokhi,Bell, Stacey,Shirran, Sally L.,Botting, Catherine H.,Slawin, Alexandra M. Z.,Hulme, Alison N.,Lovett, Janet E.
, p. 2357 - 2361 (2016/09/28)
The synthesis and characterization of four new nitroxide-radical-containing next-generation maleimides are presented. Each new label has a single leaving group which is either a phenoxyl or bromide. The linker between the maleimide and the nitroxide-containing framework is either a racemic mixture of a short chain or an achiral longer chain. These molecules have been designed to site-specifically label vicinal cysteines in proteins for magnetic resonance studies. The characterization of the final products includes crystallography and the labeling of sperm whale myoglobin protein.
Genetically Encoded Spin Label
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Page/Page column, (2015/07/22)
The invention relates to a non-canonical amino acid of the formula I, namely A - L - X, A is a lysine or a tyrosine, L is a linker or absent, and X is an aminoxyl radical, and if A is lysine, L is bound to the N-epsilon atom of the lysine or, if L is absent, X is bound to the N-epsilon atom of the lysine; and if A is tyrosine, L is bound to the phenolic hydroxyl of the tyrosine or, if L is absent, X is bound to the phenolic hydroxyl of the tyrosine. Moreover, the invention also relates to a method for introducing a spin label into a protein and to a modified pyrrolysyl-tRNA-synthetase.
A genetically encoded spin label for electron paramagnetic resonance distance measurements
Schmidt, Moritz J.,Borbas, Julia,Drescher, Malte,Summerer, Daniel
supporting information, p. 1238 - 1241 (2014/02/14)
We report the genetic encoding of a noncanonical, spin-labeled amino acid in Escherichia coli. This enables the intracellular biosynthesis of spin-labeled proteins and obviates the need for any chemical labeling step usually required for protein electron paramagnetic resonance (EPR) studies. The amino acid can be introduced at multiple, user-defined sites of a protein and is stable in E. coli even for prolonged expression times. It can report intramolecular distance distributions in proteins by double-electron electron resonance measurements. Moreover, the signal of spin-labeled protein can be selectively detected in cells. This provides elegant new perspectives for in-cell EPR studies of endogenous proteins.
STEROIDAL ANTI-HORMONE HYBRIDS
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Page/Page column 62-63, (2010/08/08)
Disclosed are novel compounds and compositions for inhibition of androgen and estrogen receptor signaling, methods for inhibiting androgen signaling, methods for inhibiting estrogen signaling, methods for inhibiting the interaction between a co-regulatory protein and an androgen or estrogen receptor, and methods for treating cancer.
Synthesis and spectral properties of polymethine-cyanine dye-nitroxide radical hybrid compounds for use as fluorescence probes to monitor reducing species and radicals
Sato, Shingo,Tsunoda, Minoru,Suzuki, Minoru,Kutsuna, Masahiro,Takido-uchi, Kiyomi,Shindo, Mitsuru,Mizuguchi, Hitoshi,Obara, Heitaro,Ohya, Hiroaki
experimental part, p. 2030 - 2039 (2009/03/12)
Various hybrid compounds comprised of two types of nitroxide radicals and either a pentamethine (Cy5) or trimethine cyanine (Cy3) were synthesized. The nitroxide radicals were linked either via an ester-bond to one or two N-alkyl carboxyl-terminated groups of Cy5, or via two amido-bonds (aminocarbonyl or carbonylamino group) to the 5-position of the indolenine moieties of Cy5 and Cy3. Changes in fluorescence and ESR intensities of the hybrid compounds were measured before and after addition of Na ascorbate in PBS (pH 7.0) to reduce the radicals. Among the hybrid compounds synthesized, those that linked the nitroxide radicals via an aminocarbonyl residue at the 5-position of the indolenine moieties on Cy5 and Cy3 exhibited a 1.8- and 5.1-fold increase in fluorescence intensity with the reduction of the nitroxide segment by the addition of Na ascorbate, respectively. In contrast, fluorescence intensity was not enhanced in the other hybrid compounds. Thus, the hybrid compounds which exhibited an increase in fluorescent intensity with radical reduction can be used in the quantitative measurement of reducing species such as Fe2+ and ascorbic acid, and hydroxyl radicals. Because these hybrid compounds have the advantage of fluorescing at longer wavelengths-661 (Cy5) or 568 (Cy3) nm, respectively, they can be used to measure radical-reducing species or radicals either in solution or in vivo.
