210907-84-9Relevant articles and documents
Glycan-Directed Grafting-from Polymerization of Immunoglobulin G: Site-Selectively Modified IgG-Polymer Conjugates with Preserved Biological Activity
Chou, Chih-Hung,Lin, Po-Chiao
, p. 3086 - 3095 (2018)
Antibody and related antibody drugs for the treatment of malignancies have led to progress in targeted cancer therapy. Preparation of diverse antibody conjugates is critical for preclinical and clinical applications. However, precise control in tagging molecules at specific locations on antibodies is essential to preserve their native function. In this study, a synthetic boronic acid (BA)-tosyl initiator was used to trigger a glycan-directed modification of IgGs, and the obtained IgG macroinitiators allowed a growth of the poly N-isopropylacrylamide (PNIPAAm) chains specifically at Fc-domains. Therefore, the PNIPAAm chains are located away from the critical antigen-binding domains (Fab), which could reasonably prevent the loss of biological activity after the attachment of polymer chains. According to the proposed strategy, a site-selectively modified anticoncanavalin A (Con A) antibody-PNIPAAm conjugate showed 6-times higher efficiency in the binding of targeted Con A antigen to a randomly conjugated anti-Con A antibody-PNIPAAm conjugate. In this study, we developed the first chemical strategy for the site-specific preparation of IgG-polymer conjugates with conserved biological activity as well as intact glycan structures.
Tuning the sugar-response of boronic acid block copolymers
Cambre, Jennifer N.,Roy, Debashish,Sumerlin, Brent S.
, p. 3373 - 3382 (2012)
A detailed study of the pH- and sugar-responsive behavior of poly(3-acrylamidophenylboronic acid pinacol ester)-b-poly(N,N- dimethylacrylamide) (PAPBAE-b-PDMA) block copolymers is presented. Reversible addition-fragmentation chain transfer (RAFT) polymerization of the pinacol ester of 3-acrylamidophenylboronic acid resulted in homopolymers with molecular weights between 12,000 and 37,000 g/mol. The resulting homopolymers were employed as macro-chain transfer agents during the polymerization of N,N-dimethylacrylamide (DMA). Successful chain extension and removal of the pinacol protecting groups to yield poly(3-acrylamidophenylboronic acid)-b-PDMA (PAPBA-b-PDMA) with free boronic acid moieties resulted in pH- and sugar-responsive block copolymers that were subsequently investigated for their behavior in aqueous solution. The PAPBA-b-PDMA block copolymers were capable of solution self-assembly due to the PAPBA block being water-insoluble below its pKa. The resulting aggregates were demonstrated to solubilize and release model hydrophobic compounds, as demonstrated by fluorescence studies. Dissociation of the aggregates was induced by raising the pH above the pK a of the boronic acid residues or by adding sugars capable of forming boronate esters. Aggregate size, dissociation kinetics, and the effect of various sugars were considered. The critical sugar concentration needed to induce aggregate dissociation was tuned by incorporation of hydrophilic DMA units within the PAPBA responsive segment to yield PDMA-b-poly(3- acrylamidophenylboronic acid-co-DMA) block copolymers.
Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C-O Bond Activation
Pein, Wesley L.,Wiensch, Eric M.,Montgomery, John
supporting information, (2021/06/28)
The conversion of silyloxyarenes to boronic acid pinacol esters via nickel catalysis is described. In contrast to other borylation protocols of inert C-O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Sequential cross-coupling reactions were achieved by leveraging the orthogonal reactivity of silyloxyarenes, which could then be functionalized subsequently.
Development and Application of Efficient Ag-based Hydrogenation Catalysts Prepared from Rice Husk Waste
Unglaube, Felix,Kreyenschulte, Carsten Robert,Mejía, Esteban
, p. 2583 - 2591 (2021/04/09)
The development of strategies for the sustainable management and valorization of agricultural waste is of outmost importance. With this in mind, we report the use of rice husk (RH) as feedstock for the preparation of heterogeneous catalysts for hydrogenation reactions. The catalysts were prepared by impregnating the milled RH with a silver nitrate solution followed by carbothermal reduction. The composition and morphology of the prepared catalysts were fully assessed by IR, AAS, ICP-MS, XPS, XRD and STEM techniques. This novel bio-genic silver-based catalysts showed excellent activity and remarkable selectivity in the hydrogenation of nitro groups in both aromatic and aliphatic substrates, even in the presence of reactive functionalities like halogens, carbonyls, borate esters or nitriles. Recycling experiments showed that the catalysts can be easily recovered and reused multiple times without significant drop in performance and without requiring re-activation.
