Urushiol Detection using a Profluorescent Nitroxide

Braslau, Rebecca; Rivera, Frank; Lilie, Erin; Cottman, MariEllen

doi:10.1021/jo301135m

Cited by 17 publications

(6 citation statements)

References 57 publications

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“…In addition to the identification of radicals in a diamagnetic background by EPR, radicals can be spatially located through ESR imaging, 1-2 and can be indirectly detected through their ability as efficient fluorescence quenchers. [3][4][5][6][7][8][9][10][11] and through NMR spin relaxation techniques [12][13][14][15][16] In particular, the return of fluorescence combined with loss of an ESR signal when a free radical is destroyed is a powerful method for the detection of various species; recent examples include urushiols, 17 ascorbic acid [18][19][20] and nicotine. 21 Attachment of radicals to a dendrimer core has been recently used to provide a novel, gadolinium free MRI contrast agent.…”

Section: Introductionmentioning

confidence: 99%

Water soluble, chiral, verdazyl radicals derived from aldoses

Grewal

Changoco

et al. 2016

Tetrahedron

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Graphical AbstractAbstract Condensation of 2,4-diisopropylcarbonobis(hydrazide) bis-hydrochloride with a series of aldoses gives rise to tetrazanes that can be oxidized with potassium ferricyanide to give stable verdazyl radicals in good yield. The radicals are stable under ambient conditions, and are soluble in water and polar organic solvents. Aqueous solutions are stable over a range of both acidic and basic pH and do not react significantly with ascorbic acid or hydrogen peroxide. The radicals quench fluorescence from long lived fluorophores such as pyrene, or when there is an association between the radicals and the fluorophore.These radicals thus provide the foundations of a new series of radical probes and fluorescence quenchers.

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Section: Introductionmentioning

confidence: 99%

Water soluble, chiral, verdazyl radicals derived from aldoses

Grewal

Changoco

et al. 2016

Tetrahedron

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“…Following the canonical reactions of organoboranes with oxygen-centered radicals, this reaction leads to B–C scission. The presence of heteroatoms adjacent to boron, and delocalized SOMOs in the attacking radicals, suggests that when catecholboranes are used as radical precursors in reactions with nitroxides and sulfonyl radicals, ,,, they react similarly to peroxyl radicals.…”

Section: Discussionmentioning

confidence: 99%

Interrupted Homolytic Substitution Enables Organoboron Compounds to Inhibit Radical Chain Reactions Rather than Initiate Them

Wu,

Vlaming,

Donohoe

et al. 2023

J. Am. Chem. Soc.

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The reactions of organoboranes with peroxyl radicals are key to their use as radical initiators for a vast array of radical chain reactions, particularly at low temperatures where high stereoselectivity or regioselectivity is desired. Whereas these reactions generally proceed via concerted homolytic substitution (S H 2) mechanisms, organoboranes that bear groups that can stabilize tetracoordinate boron radical "ate" complexes (e.g., catecholboranes) undergo this reaction via a stepwise addition/ fragmentation sequence and serve as useful stoichiometric alkyl radical precursors. Here we show that arylboronic esters and amides derived from catecholborane and diaminonaphthaleneborane, respectively, are potent radical-trapping antioxidants (RTAs). Mechanistic studies reveal that this is because the radical "ate" complexes derived from peroxyl radical addition to boron are sufficiently persistent to trap another radical in an interrupted S H 2 reaction. Remarkably, the reactivity of these organoboranes as inhibitors of autoxidation was shown to translate from simple hydrocarbons to the phospholipids of biological membranes such that they can inhibit ferroptosis, the cell death modality driven by lipid autoxidation and relevant in neurodegeneration and other major pathologies. The unique mechanism of these organoboranes is one of only a handful of RTA mechanisms that are not based on H-atom transfer processes and provide a new dimension to boron chemistry and its applications.

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“…25 Isoproterenol is a catecholamine and has a structure very similar to propranolol, suggesting that it may be recognized by boronic acid (Fig. 6A) 26,27 as well as by the propranolol-imprinted nanoparticles (Fig. 6B).…”

Section: Versatile Molecular Binding By Multi-functional Colloidosomesmentioning

confidence: 99%

Molecular recognition with colloidosomes enabled by imprinted polymer nanoparticles and fluorogenic boronic acid

Shen

Uddin

et al. 2013

J. Mater. Chem. B

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Multifunctional colloidosomes are prepared from molecularly imprinted polymer nanoparticles and fluorogenic boronic acid using a Cu(I)-catalyzed click reaction. The molecular selectivity of the colloidosomes was investigated by radioligand binding analysis, which indicated that the inter-particle click reaction did not affect the molecular specificity of the MIP nanoparticles on the colloidosomes for the model template, propranolol. Besides specific molecular recognition of the MIP nanoparticles, the colloidosomes also displayed dose-dependent fluorescence response to fructose at physiological pH.Moreover, the immobilized boronic acid in the core could effectively bind isoproterenol, a template analogue containing a catecholamine moiety. The depletion of isoproterenol from solution allowed the MIP nanoparticles on the colloidosomes to bind propranolol more efficiently. The pre-designed molecular selectivity and fluorescence response of the colloidosomes are interesting for potential applications in controlled delivery, chemical sensing and bioseparation.

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Urushiol Detection using a Profluorescent Nitroxide

Cited by 17 publications

References 57 publications

Water soluble, chiral, verdazyl radicals derived from aldoses

Water soluble, chiral, verdazyl radicals derived from aldoses

Interrupted Homolytic Substitution Enables Organoboron Compounds to Inhibit Radical Chain Reactions Rather than Initiate Them

Molecular recognition with colloidosomes enabled by imprinted polymer nanoparticles and fluorogenic boronic acid

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