An analysis of hydrogen peroxide in an aqueous extract of cigarette smoke, which contains many redox-active compounds, requires a method with high selectivity. An aqueous extract of the particulate phase of cigarette smoke was analyzed by HPLC with an electrochemical detector (ECD). Samples were prepared by collecting the particulate phase of the cigarette smoke on a glass fiber filter and extracting it with a phosphate buffer. The obtained solution was purified by using a Waters Oasis MCX cation-exchange cartridge, and then analyzed by an HPLC-ECD system with a Shodex KS-801 mixed-mode resin column. Pre-injecting hydrogen peroxide at a high concentration into the HPLC instrument stabilized the analytical results. The recovery of hydrogen peroxide by using an extract of the particulate phase of the cigarette smoke was more than 80%. An increase in the amount of hydrogen peroxide was observed during extraction with the phosphate buffer at higher pH values. In contrast, extraction with phosphoric acid did not increase the amount of hydrogen peroxide during extraction.
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http://dx.doi.org/10.1271/bbb.90324 | DOI Listing |
Lab Chip
January 2025
Nanobioelectronics Laboratory (NBEL), Department of Biomedical Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, 8410501 Beer Sheva, Israel.
Dissolved oxygen is crucial for metabolism, growth, and other complex physiological and pathological processes; however, standard physiological models (such as organ-on-chip systems) often use ambient oxygen levels, which do not reflect the lower levels that are typically found . Additionally, the local generation of reactive oxygen species (ROS; a key factor in physiological systems) is often overlooked in biology-mimicking models. Here, we present a microfluidic system that integrates electrochemical dissolved oxygen sensors with lab-on-a-chip technology to monitor the physiological oxygen concentrations and generate hydrogen peroxide (HO; a specific ROS).
View Article and Find Full Text PDFJ Chem Inf Model
January 2025
Department of Chemistry, University of Rome, Sapienza, P.le A. Moro 5, 00185 Rome, Italy.
The oxidation of Met residues in proteins is a complex process, where protein-specific structural and dynamical features play a relevant role in determining the reaction kinetics. Aiming to a full-side perspective, we report here a comprehensive characterization of Met oxidation kinetics by hydrogen peroxide in a leptin protein case study. To do that, we estimated the reaction-free energy profile of the Met oxidation via a QM/MM approach, while the kinetics of the formation of the reactive species were calculated using classical molecular dynamics (MD) simulations.
View Article and Find Full Text PDFBull Exp Biol Med
January 2025
Hunan University of Chinese Medicine, Changsha, Hunan, China.
We studied the effect of acteoside on a model of human corneal epithelial cells (HCEC) injury induced by HO. HCEC were divided into 4 groups and cultured for 24 h in normal medium (intact and control groups, respectively), or in a medium containing DMSO or 160 μM acteoside (DMSO and acteoside groups, respectively). Then, HO solution was added to HCEC for 4 h, except for intact cells.
View Article and Find Full Text PDFSci Rep
January 2025
Chemistry Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
In a quest to innovate biologically active molecules, the benzoylation of 4,6-dimethylpyrimidine-2-thiol hydrochloride (1) with benzoyl chloride derivatives was employed to produce a series of pyrimidine benzothioate derivatives (2-5). Subsequent sulfoxidation of these derivatives (2-5) using hydrogen peroxide and glacial acetic acid yielded a diverse array of pyrimidine sulfonyl methanone derivatives (6-9). In parallel, the sulfoxidation of pyrimidine sulfonothioates (10-12) yielded sulfonyl sulfonyl pyrimidines (13-15), originating from the condensation of compound 1 with sulfonyl chloride derivatives.
View Article and Find Full Text PDFActa Parasitol
January 2025
Department of Molecular Biology and Genetics, Ordu University, Ordu, Turkey.
Purpose: Acanthamoeba species are eucaryotic protozoa found predominantly in soil and water. They cause ulceration and vision loss in the cornea (Acanthamoeba keratitis) and central nervous system (CNS) infection involving the lungs (granulomatous amoebic encephalitis). Antiparasitic drugs currently used in the treatment of infections caused by Acanthamoeba species are not effective at the desired level in some anatomical regions such as the eye and CNS.
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