Proteases immobilized on nanomaterials for biocatalytic, environmental and biomedical applications: Advantages and drawbacks

: Proteases have gained significant scientific and industrial interest due to their unique biocatalytic characteristics and broad-spectrum applications in different industries. The development of robust nanobiocatalytic systems by attaching proteases onto various nanostructured materials as fascinating and novel nanocarriers has demonstrated exceptional biocatalytic performance, substantial stability, and ease of recyclability over multiple reaction cycles under different chemical and physical conditions. Proteases immobilized on nanocarriers may be much more resistant to denaturation caused by extreme temperatures or pH values, detergents, organic solvents, and other protein denaturants than free enzymes. Immobilized proteases may present a lower inhibition. The use of non-porous materials in the immobilization prevents diffusion and steric hindrances during the binding of the substrate to the active sites of enzymes compared to immobilization onto porous materials; when using very large or solid substrates, orientation of the enzyme must always be adequate. The advantages and problems of the immobilization of proteases on nanoparticles are discussed in this review. The continuous and batch reactor operations of nanocarrier-immobilized proteases have been successfully investigated for a variety of applications in the leather, detergent, biomedical, food, and pharmaceutical industries. Information about immobilized proteases on various nanocarriers and nanomaterials has been systematically compiled here. Furthermore, different industrial applications of immobilized proteases have also been highlighted in this review

Efficient preparation of trisubstituted alkenes using the SmI2 modification of the Julia-Lythgoe olefination of ketones and aldehydes

High yields of di- and tri-substituted alkenes are: obtained by a modification of the Julia-Lythgoe olefination reaction involving the in situ capture of intermediate beta -alkoxy-sulfones by benzoyl or trimethylsilyl chloride, followed by SmI2-mediated reductive elimination. This novel protocol also provides a connective preparation of dienyl ethers, which are important partners in Diels-Alder cycloadditions. (C) 2001 Elsevier Science Ltd. All rights reserved

Multisystem inflammatory syndrome with refractory cardiogenic shock due to acute myocarditis and mononeuritis multiplex after SARS-CoV-2 infection in an adult.

A 22-year-old male with a typical history of pauci-symptomatic COVID-19 3 weeks earlier, confirmed by positive serology for SARS-CoV-2 (IgG), was admitted to the intensive care unit because of severe myocarditis with refractory cardiogenic shock that required extracorporeal life support. Due to a clinical presentation suggestive of Kawasaki-like disease with coronary aneurysm and severe systemic inflammation, intravenous immunoglobulins were administered in combination with tocilizumab. The initial clinical course was favourable with these treatments. However, the patient subsequently developed a severe mononeuritis multiplex leading to bilateral foot drop, which required intensive immunosuppressive therapy (corticosteroids, cyclophosphamide and rituximab). The clinical presentation meets the criteria for multisystem inflammatory syndrome associated with SARS-CoV-2, but includes very severe organ damages. Early recognition, a multidisciplinary approach and aggressive therapeutic intervention can lead to a favourable outcome

A Direct Route into Fused Imidazo-diazines and Imidazo-pyridines Using Nucleophilic Nitrenoids in a Gold-Catalyzed Formal [3 + 2]-Dipolar Cycloaddition

Pyridinium <i>N</i>-(hetero­aryl)­aminides can be employed as robust and practical synthetic equivalents of nucleophilic 1,3-<i>N</i>,<i>N</i>-dipoles in a formal cycloaddition onto electron-rich alkynes under gold catalysis. Convergent and regioselective access to five types of imidazo-fused heteroaromatics is provided from the appropriate aminide. The efficient transformation accommodates significant structural variation around the aminide, ynamide, or indolyl-alkyne reactants and tolerates sensitive functional groups