Acid dissociation constants (Ka) and their temperature dependencies (.DELTA.Ha, .DELTA.Sa) for a series of carbon- and nitrogen-substituted hydroxamic acids in aqueous solution

Monzyk, Br̀uce; Crumbliss, Alvin L.

doi:10.1021/jo01311a024

Cited by 83 publications

(53 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Oxidation of aceto-HX by • OH in the presence of TEMPOL or C-PTIO • OH radical was generated upon irradiation of N 2 O-saturated solutions containing 4 mM aceto-HX (pK a =9.0 [48]), 100 μM nitroxide, 55 U mL −1 catalase and 10 mM phosphate buffer at pH 8.3. Under such conditions • OH reacts exclusively with the hydroxamate moiety forming the transient nitroxide radical (reaction (18)) [7].…”

Section: The Reaction Of Hyponitrite Radical With Nitroxides and Tempmentioning

confidence: 99%

The use of cyclic nitroxide radicals as HNO scavengers

Samuni¹,

Samuni²,

Goldstein³

2013

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

Section: The Reaction Of Hyponitrite Radical With Nitroxides and Tempmentioning

confidence: 99%

The use of cyclic nitroxide radicals as HNO scavengers

Samuni¹,

Samuni²,

Goldstein³

2013

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

“…This resistant phenotype was maintained by pulsing cells during every third passage with cisplatin (1 mM). Both cell lines were maintained in RPMI-1640 media with Earle's balanced salt solution (EBSS) containing 1.5 g L 21 sodium bicarbonate, 2 mM L-glutamine, 100 U ml 21 penicillin, 100 mg ml 21 streptomycin and 10% (v/v) foetal bovine serum (FBS). These two model cell lines were grown at 37 uC in a humidified atmosphere with 5% CO 2 and were in the exponential phase of growth at the time of inclusion in cytotoxicity assays.…”

Section: Cell Lines and Cell Culturementioning

confidence: 99%

Synthesis and X-ray diffraction structures of novel half-sandwich Os(ii)-and Ru(ii)-hydroxamate complexes

et al. 2012

View full text Add to dashboard Cite

Novel water soluble half-sandwich complexes of the general formulae [M(g 6 -p-cym)(ha)] 2 (CF 3 SO 3 ) 2 , [M(g 6 -p-cym)(ha)Cl] or [M(g 6 -p-cym)(ha)(py)]X (M = Os, Ru; ha = hydroxamate; py = pyridine; X = Cl 2 or CF 3 SO 3 2 ), incorporating metal-containing entities and hydroxamates both with potential anti-proliferative features, were prepared and characterized by elemental analysis, spectroscopy (NMR, IR) and ESI mass spectrometry. The X-ray crystal structure of (17) occurs, and the crystal and molecular structure has been determined by X-ray method. Complexes 1, 5-8, 10 and 14 were tested for their in vitro cytotoxicity, using human-derived ovarian cancer cell lines (A2780 and A2780 cisR), and showed no anti-proliferative effect in the concentration range (0-200 mM) studied.

show abstract

“…A large number of papers dealing with theoretical and experimental aspects of hydroxamic acids' acidity have been published, 17 among which we have recently published a thermodynamic study of the acid-base properties of HU and NMHU. 18 It was concluded that the electronic properties of the functional groups, R 1 and R 2 , play a significant role in the ionization of hydroxamic acids, 19 but an unresolved dispute whether hydroxamic acids in water deprotonate at the oxygen or the nitrogen atom of hydroxamic moiety is still open for debate.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and Mechanism of Oxidation of Hydroxyurea Derivatives with Hexacyanoferrate(III) in Aqueous Solution

Budimir¹,

Weitner²,

Kos³

et al. 2011

Croat. Chem. Acta

View full text Add to dashboard Cite

Abstract. Kinetics and mechanisms of the oxidation of methoxyurea and N-methylhydroxyurea were studied in neutral and basic aqueous solutions. The obtained pH dependences of the oxidation rates indicate that for both hydroxyureas the reactive species are the deprotonated ones. The second order rate constants, the activation enthalpies and the activation entropies for the reactions of methoxyurea (O-methylhydroxyurea) and N-methylhydroxyurea anions with Fe(CN) 6 3− at 25 o C, I = 2 mol dm −3 (NaClO 4 ) were determined as (5.06 ± 0.01)  10 2 mol −1 dm 3 s −1 , (1.92 ± 0.02)  10 4 mol −1 dm 3 s −1 , 27 ± 1 kJ mol, and 107 ± 4 J mol −1 K −1 , respectively. The pK a value of methoxyurea at 25 o C and 2 mol dm −3 ionic strength was determined kinetically as 12.7 ± 0.1 and the thermodynamic parameters for the deprotonation reaction were determined as Δ a H = 43 ± 1 kJ mol, and. When the kinetic results are compared with the data reported for hydroxyurea, an inverse dependence of the rate constants on the pK a of the hydroxyurea derivatives at 25 o C is observed. Such unexpected behaviour has been explained by the ab initio calculations and NBO analysis of HOMOs for all three hydroxyureates. (doi: 10.5562/cca1799)

show abstract

Acid dissociation constants (Ka) and their temperature dependencies (.DELTA.Ha, .DELTA.Sa) for a series of carbon- and nitrogen-substituted hydroxamic acids in aqueous solution

Cited by 83 publications

References 0 publications

The use of cyclic nitroxide radicals as HNO scavengers

The use of cyclic nitroxide radicals as HNO scavengers

Synthesis and X-ray diffraction structures of novel half-sandwich Os(ii)-and Ru(ii)-hydroxamate complexes

Kinetics and Mechanism of Oxidation of Hydroxyurea Derivatives with Hexacyanoferrate(III) in Aqueous Solution

Contact Info

Product

Resources

About