67616-44-8Relevant articles and documents
Evaluation of transnitrosating ability of N-nitrosoguanidines to alkyl thiols and thiol amino acids
Ribeiro, Lara,García-Río, Luis,Araújo, M. Eduarda
, p. 1177 - 1184 (2016/02/16)
The transfer of the nitroso group from 1-nitroso-1-methyl-3-tolylsulfonylguanidine (NOTSG) and 1-nitroso-1-methyl-3-benzoylguanidine (NOBMG) to some thiols, including the amino acid cysteine, was studied in a pH range between 7 and 12. The measured apparent bimolecular rate constant of transnitrosation (ktrapp) revealed a bell-shaped pH dependence that clearly indicates that both nitrosoguanidines react through the corresponding neutral form, and the nucleophiles in the thiolate anion form to give the corresponding S-nitrosothiol. Regarding cysteine, the existence of three macroscopic acidity constants influenced the kinetic behavior of the transnitrosation reaction. Transnitrosation rates (ktr) of the two possible nucleophilic species were obtained and it was found that NOBMG has lower thiol transnitrosation capacity due to the lower electron-withdrawing effect of benzoyl group and to the possible stabilization of the anionic structure as a consequence of the establishment of the intramolecular hydrogen bond. The ktr values of the studied nucleophiles were calculated and a Br?nsted-type plot was established giving unexpected negatives βnuc(βnuc(NOBMG)=-0,17 and βnuc(NOTSG)=-0,11). The atypical βnuc values were attributed to the need for previous desolvation of the nucleophile.
Nitroso group transfer from N-nitrososulfonamides to thiolate ions. Intrinsic reactivity
Adam,García-Río,Leis,Moreira
, p. 8822 - 8829 (2007/10/03)
The nitroso group transfer from N-nitrososulfonamides to thiolate ions was studied. Based on the results, the reaction rate is strongly dependent on the nature of the leaving group (αlg ≈ - 1.30), but virtually independent of the basicity of th
Equilibrium and kinetics studies of transnitrosation between S-nitrosothiols and thiols
Wang, Kun,Wen, Zhong,Zhang, Wei,Xian, Ming,Cheng, Jin-Pei,Wang, Peng George
, p. 433 - 436 (2007/10/03)
Using UV-vis spectrometrical measurements, equilibrium constants for NO transfer between S-nitroso-N-acetyl-penicillamine (SNAP) and different thiols as well as kinetic data for NO transfer from S-nitroso bovine serum albumin (BSANO) to thiols have been obtained. NO transfer from SNAP to other primary/secondary thiols are thermodynamically favorable, whereas other S-nitrosothiols exhibit similar NO transfer potential. The obtained Gibbs free energy, enthalpy and entropy data indicated that NO transfer reactions from SNAP to four thiols are exothermic with entropy loss. The kinetic behavior of BSANO/RSH transfer can be related to both the acidity of sulfhydryl group and the electronic structure in thiol.
A convenient method for production of thionitrites and disulfides under mild and heterogeneous condition
Zolfigol, Mohammad Ali
, p. 1593 - 1597 (2007/10/03)
Thiols can be readily converted to their corresponding thionitrite with a combination of inorganic acidic salts and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur-nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals.