Performic Acid Oxidation Research Articles

Assessing the effectiveness of performic acid disinfection on effluents: focusing on bacterial abundance and diversity.

Poorly-treated wastewater harbors harmful microorganisms, posing risks to both the environment and public health. To mitigate this, it is essential to implement robust disinfection techniques in wastewater treatment plants. The use of performic acid (PFA) oxidation has emerged as a promising alternative, due to its powerful disinfection properties and minimal environmental footprint. While PFA has been used to inactivate certain microbial indicators, its potential to tackle the entire microbial community in effluents, particularly resistant bacterial strains, remains largely unexplored. The present study evaluates the efficacy of PFA disinfection on the microbial communities of a WWTP effluent, through microbial resistance mechanisms due to their membrane structure. The effluent microbiome was quantified and identified. The results showed that the number of damaged cells increases with CT, reaching a maximum for CT = 240mg/L•min and plateauing around 60mg/L•min, highlighting the optimal conditions for PFA-disinfection against microbial viability. A low PFA level with a 10-min contact time significantly affected the microbial composition. It is worth noting the sensitivity of several bacterial genera such as Flavobacterium, Pedobacter, Massilia, Exiguobacterium, and Sphingorhabdus to PFA, while others, Acinetobacter, Leucobacter, Thiothrix, Paracoccus, and Cloacibacterium, showed resistance. The results detail the resistance and sensitivity of bacterial groups to PFA, correlated with their Gram-positive or Gram-negative membrane structure. These results underline PFA effectiveness in reducing microbial levels and remodeling bacterial composition, even with minimal concentrations and short contact times, demonstrating its suitability for widespread application in WWTPs.

A High-Throughput Absolute Quantification of Protein-Bound Sulfur Amino Acids from Model and Crop Plant Seeds.

In this procedure, we describe a high-throughput absolute quantification protocol for the protein-bound sulfur amino acids, cysteine (Cys) and methionine (Met), from plant seeds. This procedure consists of performic acid oxidation that transforms bound Cys into cysteic acid (CysA) and bound Met into methionine sulfone (MetS) followed by acid hydrolysis. The absolute quantification step is performed by multiple reaction monitoring tandem mass spectrometry (LC-MS/MS). The approach facilitates the analysis of a few hundred samples per week by using a 96-well plate extraction setup. Importantly, the method uses only ∼4 mg of tissue per sample and uses the common acid hydrolysis protocol, followed by water extraction that includes DL-Ser-d3 and L-Met-d3 as internal standards to enable the quantification of the absolute levels of the protein-bound Cys and Met with high precision, accuracy, and reproducibility. The protocol described herein has been optimized for seed samples from Arabidopsis thaliana, Glycine max, and Zea mays but could be applied to other plant tissues. © 2023 Wiley Periodicals LLC. Basic Protocol: Analysis of protein-bound cysteine and methionine from seeds.

Enhanced and Facile Desulfurization of Commercial Oil Using Air-Assisted Performic Acid Oxidation System

Abstract Heavy oil is a low-cost fuel and is extensively used in the industries, however, it contains high sulfur content, which creates serious environmental problems. Conventional hydrodesulfuriz...

Evaluation of a performic acid oxidation method for quantifying amino acids in freshwater species

AbstractThiol amino acids in proteins store metals like mercury, but established methods for their quantitation in freshwater species have had limited application and evaluation. As such, literature on the amino acid composition of aquatic species often lacks the thiols cysteine and methionine. Here, we evaluated a performic acid (PFA) oxidation method to determine its suitability to measure cysteine and methionine, as well as 15 other amino acids, in novel matrices (zooplankton, benthic invertebrates, fishes, and algae). Protein‐bound amino acids were oxidized with PFA, hydrolyzed in hydrochloric acid, derivatized with AccQ·Tagultra (Waters), and separated by ultra‐high performance liquid chromatography with fluorescence detection. PFA oxidation was successful in determining precise results for 15 amino acids, including the sulfur amino acids, with the complete loss of tyrosine (TYR) and poor precision of phenylalanine (PHE). The overall variability of the method was 11% (excluding TYR and PHE), or 6% when reported as relative percentages, comparable to methods without PFA oxidation in other matrices. Except for TYR and thiols, PFA oxidation did not affect the amino acid composition of these biota. Overall, the findings were reproducible and comparable to other approaches and suggest this is a rigorous method for measuring sulfur amino acids and the overall amino acid composition for aquatic biota, both of which are rare in the literature.

Amino acid profile and protein quality in tuber and leaf of Coccnia abyssinica (Lam.) (Cogn.) accessions of Ethiopia.

The protein content and amino acid profile of Anchote (Coccinia abyssinica) leaves and tubers were determined from ten different accessions taken from Debre Zeit Agricultural Research Center, Ethiopia. Crude protein content was determined by Kjeldahl method and amino acid profile was analyzed using performic acid oxidation and acid hydrolysis by ninhydrin‐derivatized analysis with amino acid analyzer. Crude protein content of Anchote tuber ranged from 10.70% ± 0.26% to 13.72% ± 0.10%, whereas the crude protein content in leaves were ranged between 30.38 ± 0.01% (“240407‐1”) and 35.42 ± 0.05% (“223109‐1”). Total amino acid content ranged from 45.12 to 62.89 and 67.31 to 75.69 g/100 g protein for tuber and leaf samples, respectively. The mean values of essential, conditionally essential and nonessential amino acids were 37.22 & 36.79%; 28.62 & 24.10%; and 34.16 & 39.11% for tubers and leaves, respectively. Arginine in tubers and glutamic acid in leaves ranked the highest of all amino acids; while the least dominant essential amino acid was methionine in both parts. Among the essential amino acids, leucine was dominant in all accessions tested with values ranged from 3.12 to 5.32 g/100 g protein in tubers and from 5.15 to 5.65 g/100 g protein in leaves. In general, the average amino acid content was higher in the leaves (71.08 g/100 g protein) compared to the tubers (51.11 g/100 g protein). The nutritional quality of Coccinia abyssinica leaves and tubers range as follows: total essential amino acids (TEAA)/ total amino acids (TAA) (37.57 & 36.82%), TEAA/total non‐essential amino acids (TNEAA) ratio (0.60 & 0.58), The predicted protein efficiency ratio (P‐PER) (1.22 & 1.80), Essential amino acid index (EAAI) (35.28 & 53.93%), Predicted biological value (P‐BV) (26.76 & 47.09%), Nutritional index (4.11 & 17.71%), and Amino acid score (73 & 108) for tuber and leaf sample, respectively. A significant variability was observed in protein and amino acid profile among accessions and plant parts, and the leaf part were found to be richer in protein content and associated nutritional quality.

Surface charge fine tuning of reversed-phase/weak anion-exchange type mixed-mode stationary phases for milder elution conditions

A series of new mixed-mode reversed-phase/weak anion-exchange (RP/WAX) phases have been synthesized by immobilization of N-undecenyl-3-α-aminotropane onto thiol-modified silica gel by thiol-ene click chemistry and subsequent introduction of acidic thiol-endcapping functionalities of different type and surface densities. Click chemistry allowed to adjust a controlled surface concentration of the RP/WAX ligand in such a way that a sufficient quantity of residual thiols remained unmodified which have been capped by thiol click with either 3-butenoic acid or allylsulfonic acid as co-ligands. In another embodiment, performic acid oxidation of N-undecenyl-3-α-aminotropane-derivatized thiol-modified silica gave a RP/WAX phase with high density of sulfonic acid end-capping groups. ζ-Potential determinations confirmed the fine-tuned pI of these mixed-mode stationary phases which was shifted from 9.5 to 8.2, 7.8, and 6.5 with 3-butenoic acid and allylsulfonic acid end-capping as well as performic acid oxidation. For acidic solutes, the co-ionic endcapping leads to strongly reduced retention times and clearly allowed elution of these analytes under lower ionic strength thus milder elution conditions. In spite of the acidic endcapping, the new mixed-mode phases maintained their hydrophobic and anion-exchange selectivity as well as their multimodal nature featuring RP and HILIC elution domains at acetonitrile percentages below and above 50%, respectively. Column classification by principal component analysis of an extended retention map in comparison to a set of polar commercial and in-house synthesized stationary phases confirmed complementarity of the new mixed-mode phases with respect to HILIC, polar RP, amino and commercial mixed-mode phases.

Polymethacrylate monoliths with immobilized poly-3-mercaptopropyl methylsiloxane film for high-coverage surface functionalization by thiol-ene click reaction

In this work, new polythiol-functionalized macroporous monolithic polymethacrylate-polysiloxane composite materials are presented which can be useful substrates for highly efficient immobilization of (chiral) catalysts, chromatographic ligands, and other functional moieties by thiol-ene click reaction. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) (poly(GMA-co-EDMA)) monoliths were coated with a poly-3-mercaptopropyl methylsiloxane (PMPMS) film and subsequently the polymer was covalently immobilized by formation of crosslinks via nucleophilic substitution reaction with pendent 2,3-epoxypropyl groups on the monolith surface. This monolith, though, showed similar levels of surface coverage as a reference monolith obtained by opening of the epoxide groups with sodium hydrogen sulfide. However, a 3-step functionalization by amination of the epoxy monolith, followed by its vinylation with allylglycidyl ether and subsequent thiolation by coating of a thin polythiol (PMPMS) film and crosslinking by click reaction furnished a monolith with more than 2-fold elevated thiol coverage. Its further functionalization with a clickable chiral quinine carbamate selector clearly documented the benefit of highly dense thiol surfaces for such reactions and synthesis of functional materials with proper ligand loadings. The new monoliths were chromatographically tested in capillary electrochromatography mode using N-3,5-dinitrobenzoyl-leucine as chiral probe and the capillary column with the monolith having the highest selector coverage, produced from the precursor with the most thiols on the surface, showed the largest separation factor. By performic acid oxidation the surface characteristic could be tuned and strongly altered due to a delicate balance of enantioselective and non-specific interactions.

ChemInform Abstract: Convenient Synthesis of Various Substituted Homotaurines from Alk‐2‐enamides.

AbstractVarious substituted homotaurines (IV) are synthesized via Michael addition of thioacetic acid (II) to alk‐2‐enamides (I), followed by LiAlH4 reduction and performic acid oxidation.

Desulfurization of liquid fuels using air-assisted performic acid oxidation and emulsion catalyst

Abstract Catalytic oxidative desulfurization (ODS) of model oil and commercial oil samples was investigated using an air-assisted performic acid oxidation system with a phase transfer or emulsion catalyst comprising a quaternary ammonium salt-based heteropolyoxometalate. Different emulsion catalysts with a Keggin type heteroployoxometalate anion (containing W, Mo, and V) and cetyltrimethylammonium bromide cation were prepared and characterized by X-ray fluorescence, Fourier transform infrared spectroscopy, and scanning electron microscopy. [C16H33N(CH3)3]3[PW9Mo3O40] was the most effective catalyst in the current oxidation system, which reduced the sulfur content of the model oil from 1275 μg/g to 57 μg/g. The reactivity order of different model sulfur compounds was thiophene

Convenient Synthesis of Various Substituted Homotaurines from Alk‐2‐enamides

AbstractVarious substituted homotaurines (=3‐aminopropane‐1‐sulfonic acids) 6 were readily synthesized in satisfactory to good yields via the Michael addition of thioacetic acid to alk‐2‐enamides 3 (→4), followed by LiAlH4 reduction (→5) and performic acid oxidation (Scheme 1). The configuration of ‘anti’‐disubstituted homotaurine ‘anti’‐6h was deduced from the 3‐(acetylthio)alkanamide (=S‐(3‐amino‐1,2‐dimethyl‐3‐oxopropyl) ethanethioate)‘anti’‐4h formed in the Michael addition, which was identified via the Karplus equation analysis, and confirmed by X‐ray diffraction analysis. The current route is an efficient method to synthesize diverse substituted homotaurines, including 1‐, 2‐, and N‐monosubstituted, as well as 1,2‐, 1,N‐, 2,N‐, and N,N‐disubstituted homotaurines (Table).

ChemInform Abstract: Efficient Synthesis of N‐Protected 1‐Substituted Homotaurines from a Xanthate and Olefins.

AbstractA series of N‐protected 1‐substituted homotaurines (IV) is synthesized efficiently from xanthate (I) and various olefins via radical addition reaction followed by performic acid oxidation.

Deoxydesulfurization of liquid fuels using air assisted performic acid oxidation followed by reductive decomposition through in situ generated Ni-boride

The deoxydesulfurization of organosulfur compounds in model and commercial oil was investigated by oxidation with performic acid followed by reduction with in situ generated Ni2B under ambient conditions. The desulfurization efficiency of the process is high and is superior to the extractive ODS, since it does not require a large quantity of solvent for the extraction and also the parent hydrocarbons of the organosulfur compounds are returned to the feed, thereby avoiding loss of oil.

Efficient synthesis of N-protected 1-substituted homotaurines from a xanthate and olefins

A series of N-protected 1-substituted homotaurines was synthesized efficiently from various olefins with O-ethyl S-2-phthalimidomethylxanthate as a sulfur-aminomethylation reagent via a radical addition and subsequent performic acid oxidation. The current method is a convenient and practical method for the synthesis of 1-substituted homotaurines with high yields and short synthetic route.

Expeditious synthesis of 1-substituted taurines with diverse functionalized side-chains

A radical addition reaction and subsequent performic acid oxidation were used for the synthesis of 1-substituted taurines with diverse functionalized side-chains from N-allylphthalimide and various xanthates. The current approach shows high yields and short synthetic route and reaction time. Moreover, the current method is a convenient and practical method for the synthesis of 1-substituted taurines with different functionalized side-chains.

Synthesis of Homotaurine and 1-Substituted Homotaurines from α,β-Unsaturated Nitriles

Homotaurine and a series of 1-substituted homotaurines were readily synthesized in satisfactory to good yields via the Michael­ addition of thioacetic acid to aliphatic and aromatic α,β-unsaturated nitriles followed by lithium aluminum hydride mediated reduction and performic acid oxidation. The synthesis of 1,1-disubstituted homotaurines was attempted with β,β-disubstituted acrylonitriles as starting materials but failed due to steric hindrance. The current process is an efficient method for the synthesis of 1-substituted homotaurines.

Study of a novel glycoconjugate, thiopeptidoglycan, and a novel polysaccharide lyase, thiopeptidoglycan lyase

A typical filamentous bacterium, Sphaerotilus natans, secretes a thiolic glycoconjugate which is assembled into a microtube, so called sheath. The glycoconjugate is known to consist of a pentasaccharide-dipeptide repeating unit, but its chemical structure has not been completely elucidated. In order to determine its chemical structure, the sheath was broken down by performic acid oxidation. The released sulfonated derivative was water soluble which was suitable for detailed NMR analysis. The data exhibited the presence of two stoichiometric and one substoichiometric (relative abundance was about 0.5) acetylations, suggesting that the glycoconjugate is composed of two equimolar pentasaccharide-dipeptide repeating units each having either two or three acetyl groups. However, the position of substoichiometric acetylation could not be defined. To determine the position, the sheath was derivatized with a thiol selective fluorescent reagent followed by digestion with a specific polysaccharide lyase prepared from a sheath-degrading bacterium, Paenibacillus koleovorans. As expected, two fluorescent digests were recovered by reverse-phase HPLC and were subjected to NMR analysis. The data revealed that both digests are pentasaccharide-dipeptides which have unsaturated glucuronic acid and galactosamine residues at their reducing and non-reducing ends, respectively. It was also confirmed that one digest has 3- O-acetylated glucose residue while the other has non-derivatized glucose residue. The substoichiometric acetylation was thus identified with the 3- O-acetylation, and structural determination of the thiolic glycoconjugate was completed. By virtue of the clarification of the two digests’ structures, the cleavage site was specified as (1 → 4)-α-galactosaminic bond to glucuronic acid. Based on the present and earlier findings, we propose a novel glycoconjugate category named thiopeptidoglycan and a novel polysaccharide lyase named thiopeptidoglycan lyase.

Improvement of hydrophobic integral membrane protein identification by mild performic acid oxidation-assisted digestion

Integral membrane proteins (IMPs) are critical for the maintenance of biological systems and represent important targets for the treatment of disease. The hydrophobicity and low abundance of IMPs make them difficult to analyze. In proteomic analyses, hydrophobic peptides including transmembrane domains are often underrepresented, and this reduces the sequence coverage and reliability of the identified IMPs. Here we report a new strategy, mild performic acid oxidation treatment (mPAOT), for improvement of IMP identification. In the mPAOT strategy, the hydrophobicity of IMPs is significantly decreased by oxidizing their methionine and cysteine residues with performic acid, thereby improving the solubility and enzymolysis of these proteins. The application of the mPAOT strategy to the analysis of IMPs from human nasopharyngeal carcinoma CNE1 cell line demonstrated that many IMPs, including those with high hydrophobicity, could be reliably identified.

A Simple Synthesis of Nβ-Fmoc/Z-Amino Alkyl Thiols and their use in the Synthesis of Nβ-Fmoc/Z-Amino Alkyl Sulfonic Acids

A simple and efficient protocol for the synthesis of N β-Fmoc/Z-amino alkyl thiols is described. The approach uses sodium pyrosulfite-mediated hydrolysis of isothiouronium salts resulting from the reaction between N-protected aminoalkyl iodides and thiourea. N-Protected taurines were prepared through performic acid oxidation of the thiols and the products were further utilized for the synthesis of dipeptidosulfonamides.

Solubilization and structural determination of a glycoconjugate which is assembled into the sheath of Leptothrix cholodnii

The sheath of Leptothrix cholodnii is constructed from a structural glycoconjugate, a straight-chained amphoteric heteropolysaccharide modified with glycine and cysteine. Though the structure of the glycan core is already determined, its modifications with amino acids and other molecules are not fully resolved. In this study, we aimed to determine the chemical structure of the glycoconjugate as a whole. Enantiomeric determination of cysteine in the sheath was performed and as a result, l-cysteine was detected. NMR spectroscopy was endeavored to determine overall structure of the glycoconjugate. Prior to NMR analysis, solubilization of the glycoconjugate was attempted by adding denaturing reagents or by derivatization. As far as tested, sulfonation by performic acid oxidation was suitable for solubilization, but further improvement was achieved by N-acetylation. The approximate molecular weight of the derivative was estimated to be 4.5 × 10 4 by size-exclusion chromatography. The NMR studies for the sulfonated glycoconjugate and its N-acetylated derivative revealed that the sheath glycoconjugate is a glycosaminoglycan consisting of a pentasaccharide repeating unit which is substoichiometrically esterified with 3-hydroxypropionic acid and stoichiometrically amidated with acetic acid and glycyl- l-cysteine.

High-throughput method for on-target performic acid oxidation of MALDI-deposited samples

An information-rich on-target performic acid oxidation method, which is compatible with alkylation for differentiation of free cysteine versus disulfide-containing peptides, is described. On-target oxidation is achieved using performic acid vapor to oxidize disulfide-containing peptides and/or small proteins on the matrix-assisted laser desorption/ionization (MALDI) sample deposits. The on-target oxidation method is preferred over solution-phase oxidation methods because (1) less sample handling is required, (2) oxidation throughput is drastically increased and (3) ion suppression effects are reduced because performic acid is not added directly to the MALDI spot. The utility of this method is demonstrated by simultaneous oxidation of multiple MALDI sample deposits containing model disulfide-linked peptides, intact bovine insulin and a bovine ribonuclease A proteolytic digest.