Oxidation of amino acids by peracetic acid: Reaction kinetics, pathways and theoretical calculations

Abstract

Peracetic acid (PAA) is a sanitizer with increasing use in food, medical and water treatment industries. Amino acids are important components in targeted foods for PAA treatment and ubiquitous in natural waterbodies and wastewater effluents as the primary form of dissolved organic nitrogen. To better understand the possible reactions, this work investigated the reaction kinetics and transformation pathways of selected amino acids towards PAA. Experimental results demonstrated that most amino acids showed sluggish reactivity to PAA except cysteine (CYS), methionine (MET), and histidine (HIS). CYS showed the highest reactivity with a very rapid reaction rate. Reactions of MET and HIS with PAA followed second-order kinetics with rate constants of 4.6 ± 0.2, and 1.8 ± 0.1 M −1 ⋅s −1 at pH 7, respectively. The reactions were faster at pH 5 and 7 than at pH 9 due to PAA speciation. Low concentrations of H 2 O 2 coexistent with PAA contributed little to the oxidation of amino acids. The primary oxidation products of amino acids with PAA were [O] addition compounds on the reactive sites at thiol, thioether and imidazole groups. Theoretical calculations were applied to predict the reactivity and regioselectivity of PAA electrophilic attacks on amino acids and improved mechanistic understanding. As an oxidative disinfectant, the reaction of PAA with organics to form byproducts is inevitable; however, this study shows that PAA exhibits lower and more selective reactivity towards biomolecules such as amino acids than other common disinfectants, causing less concern of toxic disinfection byproducts. This attribute may allow greater stability and more targeted actions of PAA in various applications.

Monitoring of Peroxide in Gamma Irradiated EVA Multilayer Film Using Methionine Probe

“…As no radical species are detected in the samples, oxidation is likely due to the presence of hydrogen peroxide, peracids, or in situ generated peracids. Model experiments ( Figure S1 ) show that over a long time, H 2 O 2 affords oxidation product and that in situ generated peracetic acid is also efficient at oxidizing, as expected [ 17 , 27 ]. Indeed, the modification of EVA/EVOH/EVA multilayer film under gamma-irradiation shows the generation of acids ( Figure 8 ), degradation of the oxygen barrier property of the EVOH layer with increasing irradiation dose, [ 28 ] and the absence of EPR signal in the EVOH layer, meaning that the generation of a large amount of H 2 O 2 is very unlikely.…”

“…Indeed, as is well known in the literature, a solution of H 2 O 2 and acetic acid to generate in situ peracetic acid efficiently oxidizes a solution of methionine, as highlighted in Figure S3 (tests 2 and 5). To further confirm that peracetic acid is more efficient at oxidizing methionine than hydrogen peroxide, we carried out the experiment proposed by Du et al [ 27 ] adjusting concentrations so that they were in excess. We added acid acetic at 256 mM, hydrogen peroxide at 76 mM with 50 µM of methionine.…”

Sanitizing efficacy and antimicrobial mechanism of peracetic acid against histamine-producing bacterium, Morganella psychrotolerans

“…Therefore, the reduced amount of proteins after treating with PAA on the gel could be because of the damaged cell membrane proteins (Nakayama et al, 2013). Also, depending on previous investigations, the difference in the cell protein profiles after PAA treatment might be attributed to alterations in some metabolic or protein synthesis pathways upon PAA treatment (Du, Liu, Cao, Zhao, & Huang, 2018;Liu et al, 2018). Hence, further scientific studies are required to elucidate the underlying mechanism of PAA disinfectant function.…”

Disinfectants Used in Stomatology and SARS-CoV-2 Infection

“…Because cysteine residues are located at the active sites of many bacterial enzymes, their oxidation by oxidizing compounds leads to inactivation. 57 58 Super-oxidized water had been approved as a high-level disinfectant by FDA. 40 …”