1. Singlet Molecular Oxygen Generation in the Reaction of Biological Haloamines of Amino Acids and Polyamines with Hydrogen Peroxide † .
- Author
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Nascimento RO, Prado FM, de Medeiros MHG, Ronsein GE, and Di Mascio P
- Subjects
- Amino Acids, Polyamines, Chloramines, Tandem Mass Spectrometry, Oxygen, Acids, Hydrogen Peroxide chemistry, Singlet Oxygen chemistry
- Abstract
Leucocytes generate hypohalous acids (HOCl and HOBr) to defend the host against pathogens. In cells, hypohalous acids react with amine-containing molecules, such as amino acids and polyamines, producing chloramines and bromamines, reservoirs of oxidizing power that can potentially damage host tissues at sites of inflammation. Hypohalous acids also react with H
2 O2 to produce stoichiometric amounts of singlet molecular oxygen ( 1 O 2 ), but its generation in leucocytes is still under debate. Additionally, it is unclear whether haloamines generate 1 O 2 following a reaction with H2 O2 . Herein, we provide evidence of the generation of 1 O 2 in the reactions between amino acid-derived (taurine, N-α-acetyl-Lysine and glycine) and polyamine-derived (spermine and spermidine) haloamines and H2 O2 in an aqueous solution. The unequivocal formation of 1 O 2 was detected by monitoring its characteristic monomol light emission at 1270 nm in the near-infrared region. For amino acid-derived haloamines, the presence of 1 O 2 was further confirmed by chemical trapping with anthracene-9,10-divinylsulfonate and HPLC-MS/MS detection. Altogether, photoemission and chemical trapping studies demonstrated that chloramines were less effective at producing 1 O 2 than bromamines of amino acids and polyamines. Thus, 1 O 2 formation via bromamines and H2 O2 may be a potential source of 1 O 2 in nonilluminated biological systems., (© 2022 American Society for Photobiology.)- Published
- 2023
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