Effect of N-chloroamino acids on the erythrocyte

Robaszkiewicz, Agnieszka; Bartosz, Grzegorz; Soszyński, Mirosław

doi:10.1080/10715760701774873

Cited by 12 publications

(5 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Glutathione determination was performed according to Senft et al [32] as modified by Robaszkiewicz et al [33] . Suspension of RBCs in PBS (hematocrit of 16%) treated with different concentrations of glucose was centrifuged (5000 g , 10 min, 23 °C).…”

Section: Methodsmentioning

confidence: 99%

Effect of high glucose concentrations on human erythrocytes in vitro

et al. 2015

View full text Add to dashboard Cite

Exposure to high glucose concentrations in vitro is often employed as a model for understanding erythrocyte modifications in diabetes. However, effects of such experiments may be affected by glucose consumption during prolonged incubation and changes of cellular parameters conditioned by impaired energy balance. The aim of this study was to compare alterations in various red cell parameters in this type of experiment to differentiate between those affected by glycoxidation and those affected by energy imbalance. Erythrocytes were incubated with 5, 45 or 100 mM glucose for up to 72 h. High glucose concentrations intensified lipid peroxidation and loss of activities of erythrocyte enzymes (glutathione S-transferase and glutathione reductase). On the other hand, hemolysis, eryptosis, calcium accumulation, loss of glutathione and increase in the GSSG/GSH ratio were attenuated by high glucose apparently due to maintenance of energy supply to the cells. Loss of plasma membrane Ca2+-ATPase activity and decrease in superoxide production were not affected by glucose concentration, being seemingly determined by processes independent of both glycoxidation and energy depletion. These results point to the necessity of careful interpretation of data obtained in experiments, in which erythrocytes are subject to treatment with high glucose concentrations in vitro.

show abstract

Section: Methodsmentioning

confidence: 99%

Effect of high glucose concentrations on human erythrocytes in vitro

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The amidyl radicals are important synthetic intermediates which have been pointed out recently for their key role in the processes of human aging .…”

Section: Introductionmentioning

confidence: 99%

Photoinduced Rearrangement of AromaticN-Chloroamides to Chloroaromatic Amides in the Solid State: Inverted Π_N–Σ_NOccupational Stability of Amidyl Radicals

et al. 2011

View full text Add to dashboard Cite

We report a solid-state photochemical rearrangement reaction by which aromatic N-chloroamides exposed to UV light or sunlight are rapidly and efficiently converted to chloroaromatic amides. The course, the intermediate (nascent chlorine vs dichlorine) and the outcome of the reaction depend on the excitation (exposure time, wavelength, and intensity) and on inherent structural factors (the directing role of the substituents and, as demonstrated by the different reactivity of two polymorphs of N-chlorobenzanilide, the supramolecular structure). The photolysis of the chloroamides provides facile photochemical access to arylamidyl radicals as intermediates, which in the absence of strong hydrogen bond donors are stabilized in the reactant crystals by C-H/N-Cl···π interactions, thus, providing insight into their structure and chemistry. Thorough theoretical modeling of the factors determinant to the stability and the nature of the spin-hosting orbital evidenced that although the trans-Π(||) state (Np spin) of the amidyls is normally preferred over the trans-Σ(⊥) configuration (Nsp(2) spin), stabilization by aromatic conjugation, steric and geometry factors, as well as by electronic effects from the substituents can decrease the Π-Σ gap in these intermediates significantly, resulting in similar and, in the case of the orthogonal amide-phenyl disposition, even reversed population of the unpaired electron in the two orbitals. Quantitative correlation established that the inverted occupational spin stability and the Π(N)-Σ(N) crossover are collectively facilitated by the conformation, valence angle, and disposition of the amide group relative to the aromatic system. The stabilization and detection of a trans-Σ(⊥) radical was experimentally accomplished by steric locking of the orthogonal trans-amide conformation with double ortho-tert-butyl substitution at the phenyl ring. The effects of the single para-phenyl substituents on the relative occupational stability of the arylamidyl radical states point out to non-Hammett behavior. By including cumulative electronic effects from multiple substitutions, four distinct families of the aromatic amidyl radicals were identified. The Π(∥) state is the most stable structure of the N-phenylacetamidyl radical and of most of the substituted arylamidyls, although the Σ(⊥) and Π(⊥) states can also be stabilized by introducing tert-butyl and nitro groups, respectively.

show abstract

“…The supernatant was taken for GSH and GSSG assay and the pellet was used to determine protein content (Bradford, 1976). Thiol content was estimated using o ‐phthalaldehyde, as described previously (Senft et al , 2000; Robaszkiewicz et al , 2008). The fluorescence was measured using a TECAN Infinite 200 microplate reader at λ ex = 355 nm and λ em = 460 nm.…”

Section: Methodsmentioning

confidence: 99%

“…Hypochlorite, or the non‐ionized form, hypochlorous acid (HOCl), is known to act as a chlorinating agent as well as an oxidant. It reacts with amino acids residues, especially lysine, cysteine, methionine and tryptophan (Robaszkiewicz et al , 2008; Pattison and Davies, 2001), inactivating proteins such as aldolase, glyceraldehyde‐3‐phosphate dehydrogenase, H + ‐ATPase (King et al , 2004) and acetylcholinesterase (Robaszkiewicz et al , 2008; den Hartog et al , 2002). Oxidative deamination of lysine residues results in the formation of protein carbonyl groups (Hazell et al , 1994).…”

Section: Introductionmentioning

confidence: 99%

Sensitivity of antioxidant‐deficient yeast to hypochlorite and chlorite

Kwolek‐Mirek

Bartosz

Spickett

2011

Yeast

View full text Add to dashboard Cite

Sodium hypochlorite and sodium chlorite are commonly used as disinfectants, and understanding the mechanisms of microbial resistance to these compounds is of considerable importance. In this study, the role of oxidative stress and antioxidant enzymes in the sensitivity of the yeast Saccharomyces cerevisiae to hypochlorite and chlorite was studied. Yeast mutants lacking Cu-Zn superoxide dismutase, but not mutants deficient in cytoplasmic and peroxisomal catalase, were hypersensitive to the action of both hypochlorite and chlorite. Both compounds depleted cellular glutathione, induced the production of reactive oxygen species and decreased the viability of the cells. The toxicity of hypochlorite and chlorite was abolished by hypoxic and anoxic conditions and ameliorated by thiol antioxidants and ascorbate. The results demonstrated that the action of hypochlorite and chlorite involves the formation of superoxide and peroxide and that SOD1 is protective, probably by limiting the formation of hydroxyl radicals and damage to proteins.

show abstract

Effect of N-chloroamino acids on the erythrocyte

Cited by 12 publications

References 45 publications

Effect of high glucose concentrations on human erythrocytes in vitro

Effect of high glucose concentrations on human erythrocytes in vitro

Photoinduced Rearrangement of AromaticN-Chloroamides to Chloroaromatic Amides in the Solid State: Inverted Π_N–Σ_NOccupational Stability of Amidyl Radicals

Sensitivity of antioxidant‐deficient yeast to hypochlorite and chlorite

Contact Info

Product

Resources

About

Effect of N-chloroamino acids on the erythrocyte

Cited by 12 publications

References 45 publications

Effect of high glucose concentrations on human erythrocytes in vitro

Effect of high glucose concentrations on human erythrocytes in vitro

Photoinduced Rearrangement of AromaticN-Chloroamides to Chloroaromatic Amides in the Solid State: Inverted ΠN–ΣNOccupational Stability of Amidyl Radicals

Sensitivity of antioxidant‐deficient yeast to hypochlorite and chlorite

Contact Info

Product

Resources

About

Photoinduced Rearrangement of AromaticN-Chloroamides to Chloroaromatic Amides in the Solid State: Inverted Π_N–Σ_NOccupational Stability of Amidyl Radicals