Extracellular polysaccharides produced by some Cryptococcus species have been structurally investigated. These polymers have identical core structure, which was found to be alpha-1,3-mannan and different degrees of substitution of mannose in the core by xylose and glucuronic acid residues of side chains and different composition of side chains. Heteropolysaccharide from Cr. humicolus, the simplest one, has the same structure as the Cr. neoformans serotype D capsular polysaccharide. The Cr. skinneri polymer proved to be the most branched among Cryptococcus polysaccharides.
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Angew Chem Int Ed Engl
January 2025
Chang Chun Institute of Applied Chemistry Chinese Academy of Sciences, Key Laboratory of Polymer Ecomaterials, 5625 Renmin Street, Changchun, , 130022, Changchun, CHINA.
Living cationic polymerization (LCP) is a classical technique for precision polymer synthesis; however, due to the high sensitivity of cationic active species towards chain-transfer/termination events, it is notoriously difficult to control polymerization under mild conditions, which inhibits its progress in advanced materials engineering. Here, we unlock a practical anion-binding catalytic strategy to address the historical dilemma in LCP. Our experimental and mechanistic studies demonstrate that commercially accessible hexafluoroisopropanol (HFIP), when used in high loading, can create higher-order HFIP aggregates to tame dormant-active species equilibrium via non-covalent anion-binding principle, in turn inducing distinctive polymerization kinetics behaviors that grant efficient chain propagation while minimizing competitive side reactions.
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January 2025
University of Wisconsin Madison, Chemistry, 1101 University Ave, 53706, Madison, UNITED STATES OF AMERICA.
Many applications of enzymes benefit from activity on structurally diverse substrates. Here, we sought to engineer the decarboxylative aldolase UstD to perform a challenging C-C bond forming reaction with ketone electrophiles. The parent enzyme had only low levels of activity, portending multiple rounds of directed evolution and a possibility that mutations may inadvertently increase the specificity of the enzyme for a single model screening substrate.
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January 2025
City University of Hong Kong, Department of Physics and Materials Science, 83 Tat Chee Ave, Kowloon Tong, 999077, Hong Kong, HONG KONG.
Lithium metal batteries (LMBs) are regarded as the potential alternative of lithium-ion batteries due to their ultrahigh theoretical specific capacity (3860 mAh g-1). However, severe instability and safety problems caused by the dendrite growth and inevitable side reactions have hindered the commercialization of LMBs. To solve them, in this contribution, a design strategy of soluble lithiophilic covalent organic frameworks (COFs) is proposed.
View Article and Find Full Text PDFNanomicro Lett
January 2025
Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Fudan University, Shanghai, 200433, People's Republic of China.
Practical Zn metal batteries have been hindered by several challenges, including Zn dendrite growth, undesirable side reactions, and unstable electrode/electrolyte interface. These issues are particularly more serious in low-concentration electrolytes. Herein, we design a Zn salt-mediated electrolyte with in situ ring-opening polymerization of the small molecule organic solvent.
View Article and Find Full Text PDFNanoscale
January 2025
School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science (IACS), 2A and 2B Raja. S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
Water-soluble π-conjugated luminescent bioprobes have been broadly used in biomedical research but are limited by the nonbiodegradability associated with their rigid C-C backbones. In the present work, we introduced three naphthalene monoimide (NMI)-functionalized amphiphilic fluorescent polyesters (P1, P2, and P3) prepared by transesterification of functional diols with an activated diester monomer of adipic acid. These polyesters featured a side-chain NMI fluorophore, imparting the required hydrophobicity for self-assembly in water and endowing the polymeric nanoassemblies with green fluorescence.
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