Preparation of a novel poly-(di-ionic liquid)/BDD-modified electrode for the detection of tetrachloro-p-benzoquinone.

During the COVID-19 pandemic, the release of toxic disinfection by-products (DBPs) has increased due to the intensive, large-scale use of disinfectants. Halogenated benzoquinones (HBQs) are among the most toxic DBPs, but there is no rapid, convenient, and economical detection method. In this study, a novel PDIL/BDD-modified electrode was prepared in a mixed solvent of dimethyl sulfoxide (DMSO) and acetonitrile (ACN) by electrochemical polymerization with a di-ionic ionic liquid containing alkenyl groups as the monomer. The electrochemical behavior of tetra-chloro-p-benzoquinone (TCBQ) on the modified electrode was studied. By studying the cyclic voltammetry behavior of TCBQ on the PDIL/BDD electrode, it was concluded that the electrode reactions of TCBQ included the reduction of TCBQ to TCBQH2 (C1) and the reduction of bis-quinhydrone imidazole π-π type charge transfer complex to TCBQH2 (C2). By studying the SWV responses of TCBQ in the concentration range of 1-100 ng/L on the PDIL/BDD electrode, it was found that the reduction peak current (Ipa) had a linear relationship with the concentration. The electrochemical SWV technique was used to detect the concentration of trace TCBQ in water and is expected to be used for the detection of other HBQs in drinking water and swimming pool water.

In Situ Electrochemical Trapping and Unraveling the Mechanism of the Toxic Intermediate Metabolite N-Acetyl-p-Benzoquinone Imine of the Acetaminophen Drug and Its Biomimetic Mediated NADH Oxidation Reaction

The integrative study of the pharmacokinetics and dynamics of a drug has been of great research interest due to its authentic description of the biomedical and clinical pros and cons. Acetaminophen (N-acetyl-4-aminophenol, AcAP) is a well-known analgesic having a high therapeutic value, including the Covid-19 treatment. However, an overdose of the drug (>200 mg/kg of men) can lead to liver toxicity. An intermediate, N-acetyl-p-benzoquinone imine (NAPQI), metabolite formation has been found to be responsible for the toxicity. For the detection of NAPQI, several ex situ techniques based on electrochemical methods followed by nuclear magnetic resonance, high-performance liquid chromatography, and LC-MS were stated. For the first time, we report an in situ electrochemical approach for AcAP oxidation and NAPQI intermediate (Mw = 149.1 g mol-1) trapping on a graphitic nanomaterial, carbon black (CB)-modified electrode in pH 7 phosphate buffer solution (CB@NAPQI). The NAPQI-trapped electrode exhibited a surface-confined redox peak at E°′ = 0.350 ± 0.05 V vs Ag/AgCl with a surface excess value of 3.52 n mol cm-2. Physicochemical characterizations by scanning electron microscopy, Raman, FTIR, and in situ electrochemical quartz crystal microbalance (EQCM) techniques supported the entrapment of the molecular species. Furthermore, the scanning electrochemical microscopy (SECM) technique has been adopted for surface-mapping the true active site of the NAPQI-trapped electrode. As a biomimetic study, the mediated oxidation reaction of NADH by CB@NAPQI was demonstrated, and the mechanistic and quantitative aspects were studied using cyclic voltammetry, rotating disc electrode, amperometry, and flow injection analysis techniques. © 2023 American Chemical Society.

Quinones as Promising Compounds against Respiratory Viruses: A Review.

Respiratory viruses represent a world public health problem, giving rise to annual seasonal epidemics and several pandemics caused by some of these viruses, including the COVID-19 pandemic caused by the novel SARS-CoV-2, which continues to date. Some antiviral drugs have been licensed for the treatment of influenza, but they cause side effects and lead to resistant viral strains. Likewise, aerosolized ribavirin is the only drug approved for the therapy of infections by the respiratory syncytial virus, but it possesses various limitations. On the other hand, no specific drugs are licensed to treat other viral respiratory diseases. In this sense, natural products and their derivatives have appeared as promising alternatives in searching for new compounds with antiviral activity. Besides their chemical properties, quinones have demonstrated interesting biological activities, including activity against respiratory viruses. This review summarizes the activity against respiratory viruses and their molecular targets by the different types of quinones (both natural and synthetic). Thus, the present work offers a general overview of the importance of quinones as an option for the future pharmacological treatment of viral respiratory infections, subject to additional studies that support their effectiveness and safety.

Efficacy of broccoli and glucoraphanin in COVID-19: From hypothesis to proof-of-concept with three experimental clinical cases.

COVID-19 is described in a clinical case involving a patient who proposed the hypothesis that Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-interacting nutrients may help to prevent severe COVID-19 symptoms. Capsules of broccoli seeds containing glucoraphanin were being taken before the onset of SARS-CoV-2 infection and were continued daily for over a month after the first COVID-19 symptoms. They were found to reduce many of the symptoms rapidly and for a duration of 6-12 h by repeated dosing. When the patient was stable but still suffering from cough and nasal obstruction when not taking the broccoli capsules, a double-blind induced cough challenge confirmed the speed of onset of the capsules (less than 10 min). A second clinical case with lower broccoli doses carried out during the cytokine storm confirmed the clinical benefits already observed. A third clinical case showed similar effects at the onset of symptoms. In the first clinical trial, we used a dose of under 600 µmol per day of glucoraphanin. However, such a high dose may induce pharmacologic effects that require careful examination before the performance of any study. It is likely that the fast onset of action is mediated through the TRPA1 channel. These experimental clinical cases represent a proof-of-concept confirming the hypothesis that Nrf2-interacting nutrients are effective in COVID-19. However, this cannot be used in practice before the availability of further safety data, and confirmation is necessary through proper trials on efficacy and safety.