Mechanism formation of peracids

Bacterial Protein Tyrosine Phosphatases as Possible Targets for Antimicrobial Therapies in Response to Antibiotic Resistance

The review is focused on the bacterial protein tyrosine phosphatases (PTPs) utilized by bacteria as virulence factors necessary for pathogenicity. The inhibition of bacterial PTPs could contribute to the arrest of the bacterial infection process. This mechanism could be utilized in the design of antimicrobial therapy as adjuvants to antibiotics. The review summaries knowledge on pathogenic bacterial protein tyrosine phosphatases (PTPs) involved in infection process, such as: PTPA and PTPB from Staphylococcus aureus and Mycobacterium tuberculosis; SptP from Salmonella typhimurium; YopH from Yersinia sp. and TbpA from Pseudomonas aeruginosa. The review focuses also on the potential inhibitory compounds of bacterial virulence factors and inhibitory mechanisms such as the reversible oxidation of tyrosine phosphatases.

Study on the mechanism of furfural to maleic acid oxidized by hydrogen peroxide in formic acid solution

Although the conversion of furfural to formic acid oxidized by H2O2 in formic acid is very high, the molecular mechanism remains unknown. This work describes the entire reaction process of the condensation reaction based on the density functional theory (DFT). It is found that H acts as a shuttle throughout most of the basic reaction steps during this transformation. Besides, Baeyer–Villiger oxidation and Baeyer–Villiger rearrangement are also discovered during this process with the opening of furan ring following afterward. The reactants, products and intermediates in the reaction process are optimized; all possible reaction paths are considered as well as the energy barriers to be overcome at each step. Thermochemical data concerned with the conversion of furfural to maleic acid showed that the maximum energy barrier at 378.15[Formula: see text]K was 39.83[Formula: see text]kcal/mol. The results of this study do not only correspond with the existing conclusions about the reaction in question from previous research but also supplement to the study of the pathways and mechanisms of the reaction, which can provide reference and guidance for further research, both experimentally and theoretically.

Ultrasound assisted synthesis of performic acid in a continuous flow microstructured reactor

The present work establishes in depth study of ultrasound assisted preparation of performic acid (PFA) in a continuous flow microstructured reactor. The influence of various parameters viz. formic acid: hydrogen peroxide molar ratio, flow rate, temperature and catalyst loading on the PFA formation were studied in a continuous flow microstructured reactor. In a continuous microstructured reactor in the presence of ultrasonic irradiation, the formation of PFA was found to be dependent on the molar ratio of formic acid: hydrogen peroxide, flow rate of reactants, temperature and catalyst loading (Amberlite IR-120H). The optimized parameter values are 1:1M ratio, 50mL/h, 40°C and 471mg/cm³ respectively. Further, the performance of Amberlite IR-120H catalyst was evaluated for three successive cycles in continuous microstructured reactor. The performance of catalyst was found to be decreased with the usage of the catalyst and is attributed to neutralization of the sulfonic acid groups, catalyst shrinkage, or loss in pore sites. The experimental results revealed that, for an ultrasound assisted synthesis of PFA in continuous microstructured reactor the observed reaction time was even less than 10min. The observed intensification in the PFA synthesis process can be attributed to the intense collapse of the cavities formed at low temperature during ultrasonic irradiations, which further improved the heat and mass transfer rates with the formation of H₂O₂ during the reaction. The combined use of ultrasound and a continuous flow microstructured reactor has proved beneficial process of performic acid synthesis.

Activation of hydrogen peroxide to peroxytetradecanoic acid is responsible for potent inhibition of protein tyrosine phosphatase CD45

Hydrogen peroxide induces oxidation and consequently inactivation of many protein tyrosine phosphatases. It was found that hydrogen peroxide, in the presence of carboxylic acids, was efficiently activated to form even more potent oxidant - peroxy acid. We have found that peroxytetradecanoic acid decreases the enzymatic activity of CD45 phosphatase significantly more than hydrogen peroxide. Our molecular docking computational analysis suggests that peroxytetradecanoic acid has a higher binding affinity to the catalytic center of CD45 than hydrogen peroxide.

Novel molecular fossils of bacteria: insights into hydrothermal origin of life

Hydrothermal vents, in particular, alkaline submarine vents, are potential systems for the origin of life. Early hydrothermal vents may have imprinted on biochemical processes and housekeeping proteins of life and have hallmarked key molecules. This essay introduces new information to this discussion by focusing on newly identified sulfur-modified DNA and a heretofore ignored anhydro bond of the cell wall peptidoglycan in bacteria. It is suggested that they are novel molecular fossils that are relevant to the settings of alkaline submarine vents and harbor clues of early life. As DNA and the cell wall are bound up with genetic information and the integrity of cell, respectively, these two molecular fossils may provide insights into hydrothermal origin of life from a new angle.