A comprehensive study on the impact of the substituent on pKa of phenylboronic acid in aqueous and non-aqueous solutions: A computational approach

pH-modulated oxidation of organic pollutants for water decontamination: A deep insight into reactivity and oxidation pathway

Solution pH is one of the primary factors affecting the efficiency of water decontamination. Although the influence of pH on oxidants activation, catalyst activity, and reactive oxygen species have been widely explored, there is still a scarcity of systemic studies on the changes in the oxidation behavior of organic pollutants at different pH levels. Herein, we report the influence laws of pH on the forms, reactivities, active sites, degradation pathways, and products toxicities of organic pollutants. Changes in pH cause the protonation or deprotonation of organic pollutants and further affect their forms and chemistry (e.g., electrostatic force, hydrophobicity, and oxidation potential). The oxidation potential of organic pollutants follows the order: protonated form > pristine form > deprotonated form. Moreover, protonation or deprotonation can modify the active sites and degradation pathways of organic pollutants, wherein deprotonation renders them more susceptible to electrophilic attack, while protonation reduces their activity against electrophilic and nucleophilic attacks. Additionally, pH adjustments can modify the degradation pathway and the toxicity of transformation products. Overall, pH changes can affect the oxidation fate of organic pollutants by altering their structure, which distinguishes it from the effect of pH on oxidants or oxidant activation processes.

Direct nucleophilic and electrophilic activation of alcohols using a unified boron-based organocatalyst scaffold

Organocatalytic strategies for the direct activation of hydroxy-containing compounds have paled in comparison to those applicable to carbonyl compounds. To this end, boronic acids have emerged as valuable catalysts for the functionalization of hydroxy groups in a mild and selective fashion. Distinct modes of activation in boronic acid-catalyzed transformations are often accomplished by vastly different catalytic species, complicating the design of broadly applicable catalyst classes. Herein, we report the use of benzoxazaborine as a general scaffold for the development of structurally related yet mechanistically divergent catalysts for the direct nucleophilic and electrophilic activation of alcohols under ambient conditions. The utility of these catalysts is demonstrated in the monophosphorylation of vicinal diols and the reductive deoxygenation of benzylic alcohols and ketones respectively. Mechanistic studies of both processes reveal the contrasting nature of key tetravalent boron intermediates in the two catalytic manifolds.

SNAP@CQD as a promising therapeutic vehicle against HCoVs: an overview

This report discusses potential therapies for treating human coronaviruses (HCoVs) and their economic impact. Specifically, we explore therapeutics that can support the body's immune response, including immunoglobulin (Ig)A, IgG and T-cell responses, to inhibit the viral replication cycle and improve respiratory function. We hypothesize that carbon quantum dots conjugated with S-nitroso-N-acetylpenicillamine (SNAP) could be a synergistic alternative cure for treating respiratory injuries caused by HCoV infections. To achieve this, we propose developing aerosol sprays containing SNAP moieties that release nitric oxide and are conjugated onto promising nanostructured materials. These sprays could combat HCoVs by inhibiting viral replication and improving respiratory function. Furthermore, they could potentially provide other benefits, such as providing novel possibilities for nasal vaccines in the future. Teaser: Synergistic effect of carbon quantum dots and S-nitroso-N-acetylpenicillamine (SNAP) could be suggested as an alternative treatment for the respiratory damage caused by HCoV infections that further open possibilities of developing novel nasal vaccines.

N-Arylation of 3-Formylquinolin-2(1H)-ones Using Copper(II)-Catalyzed Chan-Lam Coupling

3-formyl-2-quinolones have attracted the scientific community's attention because they are used as versatile building blocks in the synthesis of more complex compounds showing different and attractive biological activities. Using copper-catalyzed Chan-Lam coupling, we synthesized 32 new N-aryl-3-formyl-2-quinolone derivatives at 80 °C, in air and using inexpensive phenylboronic acids as arylating agents. 3-formyl-2-quinolones and substituted 3-formyl-2-quinolones can act as substrates, and among the products, the p-methyl derivative 9a was used as a substrate to obtain different derivatives such as alcohol, amine, nitrile, and chalcone.

Expanding the chemical repertoire of protein-based polymers for drug-delivery applications

Expanding the chemical repertoire of natural and artificial protein-based polymers (PBPs) can enable the production of sequence-defined, yet chemically diverse, biopolymers with customized or new properties that cannot be accessed in PBPs composed of only natural amino acids. Various approaches can enable the expansion of the chemical repertoire of PBPs, including chemical and enzymatic treatments or the incorporation of unnatural amino acids. These techniques are employed to install a wide variety of chemical groups-such as bio-orthogonally reactive, cross-linkable, post-translation modifications, and environmentally responsive groups-which, in turn, can facilitate the design of customized PBP-based drug-delivery systems with modified, fine-tuned, or entirely new properties and functions. Here, we detail the existing and emerging technologies for expanding the chemical repertoire of PBPs and review several chemical groups that either demonstrate or are anticipated to show potential in the design of PBP-based drug delivery systems. Finally, we provide our perspective on the remaining challenges and future directions in this field.

Dual Stimuli-Responsive Dynamic Covalent Peptide Tags: Toward Sequence-Controlled Release in Tumor-like Microenvironments

Dynamic covalent chemistry (DCvC) has emerged as a versatile synthetic tool for devising stable, stimuli-responsive linkers or conjugates. The interplay of binding affinity, association and dissociation constants exhibits a strong influence on the selectivity of the reaction, the conversion rate, as well as the stability in aqueous solutions. Nevertheless, dynamic covalent interactions often exhibit fast binding and fast dissociation events or vice versa, affecting their conversion rates or stabilities. To overcome the limitation in linker design, we reported herein dual responsive dynamic covalent peptide tags combining a pH responsive boronate ester with fast association and dissociation rates, and a redox-active disulfide with slow formation and dissociation rate. Precoordination by boronic acid-catechol interaction improves self-sorting and selectivity in disulfide formation into heterodimers. The resulting bis-peptide conjugate exhibited improved complex stability in aqueous solution and acidic tumor-like extracellular microenvironment. Furthermore, the conjugate responds to pH changes within the physiological range as well as to redox conditions found inside cancer cells. Such tags hold great promise, through cooperative effects, for controlling the stability of bioconjugates under dilution in aqueous media, as well as designing intelligent pharmaceutics that react to distinct biological stimuli in cells.