Israel Journal of Chemistry最新文献

Superacidic ionomers are synthesized via CH activation/borylation followed by Suzuki coupling of aromatic rings of fluorinated poly(arylene ether)s. Properties of these superacidic ionomers, such as thermal stability, water uptake, ion exchange capacity (IEC), morphology, and proton conductivity, are systematically investigated. For comparative analysis, a polysulfone ionomer with a similar IEC was examined to elucidate the effect of polymer backbone hydrophobicity on membrane properties. The results demonstrate that polymer backbone hydrophobicity exerts a significant impact on both morphology and performance. Highly fluorinated poly(aryl ether) ionomers exhibit reduced water uptake and enhanced proton conductivity compared to low-fluorine or nonfluorinated polymer analogs. Notably, the TFHFBP-S₁ membrane achieves the highest proton conductivity, comparable to that of Nafion, across the full range of relative humidity at 100 °C.

Hydrogels emerge as promising scaffolds in tissue engineering due to their high water content and tunable mechanical and structural properties. However, balancing biocompatibility with mechanical strength remains a key challenge, especially when introducing porosity, which is crucial for cell population of the scaffold structure, subsequent proliferation and efficient mass transfer of nutrients and waste. Herein, a macroporous hydrogel scaffold composed of polyacrylamide (PAAM) and nanocellulose is presented, in which porosity is introduced via CO² generation from sodium bicarbonate decomposition during polymerization. This approach enables tunable pore architecture with minimal compromise to structural integrity, maintaining high resilience under mechanical deformation. Building on prior work demonstrating enhanced mechanical performance and cytocompatibility through nanocellulose reinforcement, this hydrogel system is now explored for cartilage tissue engineering. In vitro studies with human chondrocytes demonstrate enhanced cell adhesion, proliferation, and infiltration in scaffolds with intermediate porosity (≈300 μm), correlating with improved swelling dynamics. The hydrogel's resilience, tunable porosity, and cytocompatibility suggest its strong potential as a customizable scaffold for regenerating load-bearing, extracellular matrix-rich tissues such as cartilage.

Recent innovations in metal-free phosphorothioate synthesis have underscored increased utility as a sustainable alternative to metal-catalyzed procedures. Green approaches, such as metal-free coupling reactions and oxidations, radical-induced methods, electrochemical processes, and multicomponent reactions, were reported from 2020 to 2025 for the successful development of S-aryl phosphorothioates and S-heterocyclic phosphorothioates. These methods involve high atom economy, broad functional group tolerance, and mechanistic studies, positioning metal-free phosphorothiolation as an emergent tool of power and sustainability in modern organic synthesis under a green system.

Glycosylation plays a vital role in cellular functions, yet the synthesis of complex mucin-type O-glycans such as disialyl galacto-N-biose (DSGNB) remains significant challenge due to structural complexity and enzyme specificity. A modular chemoenzymatic strategy employing bacterial glycosyltransferases BiGalHexNAcP, LgtD, Cst-I, and an engineered Psp2,6ST A366G for the regioselective synthesis of DSGNB analogs is reported. A panel of GalNR-based acceptors (11–14), varying in anomeric configuration, aglycone, and amine protection, enables sequential one-pot β1,3-galactosylation to generate diverse GNB derivatives. BiGalHexNAcP exhibits strong preference for α-GalNR with allyl linkers and N-acetyl-protection, whereas LgtD shows broader tolerance. Subsequent α2,3-sialylation with Cst-I and CMP-Neu5Ac affords monosialyl GNBs (MSGNB, 2–10) in 80%–100% yield within 1–2 h. Final α2,6-sialylation with Psp2,6ST furnishes DSGNB (1b) regio- and stereoselectively from β-O-allyl MSGNB 3 (93% yield), while the α-O-allyl acceptor 2 produces a DSGNB:iso-DSGNB mixture (2:1). Notably, β-O-benzyl aglycones further enhance regioselectivity to 6:1. Molecular docking provides mechanistic insight, showing that in β-O-allyl MSGNB 3, the GalNAc C6-OH is positioned closer to catalytic Asp232 than in the α-O-linked analog. The method also enables the synthesis of disialyl T-antigen in 70% yield, demonstrating a broadly applicable platform for constructing well-defined O-GalNAc glycans with potential applications in biomedical research and therapeutic development.

This work reviews the conceptual and technological evolution of composite materials, emphasizing the transition from early fiber-reinforced systems to contemporary nanocomposites and molecular composites. The discussion begins with classical composites, showing the progression from manually fabricated glass fiber-polyester laminates (fiberglass) with isotropic properties to advanced composites that follow the introduction of high-performance fibers (carbon, aramid, and ultrahigh molecular weight polyethylene) of anisotropic crystallinity. The emergence of optimized laminate theories and automated manufacturing technologies enables structures with exceptional specific stiffness and strength of enhanced fracture toughness. Next, polymer nanocomposites are addressed, wherein nanoparticles, nanoplatelets, and nanofibers dramatically modify matrix behavior through mechanisms such as nanoparticle–matrix interfacial interactions, matrix nucleation, and confinement. Distinctions are drawn between nanocomposite solid solutions (weak or absent interfacial bonding) and molecular composites (strong covalent or physical bonding at the nanoparticle–matrix interface). Finally, the focus shifts toward functional applications driven by unique physical properties of nanofillers, including energy storage, electromagnetic shielding, biomedical platforms, and thermal management. Three case studies of avant-gard applications of nanocomposites illustrate this paradigm shift. Overall, the article frames the “new science” of composites as the rational design of heterogeneous, anisotropic, and nanoscale material systems optimized for structural and multifunctional performance.

Heparan sulfate (HS) is a linear polysaccharide in the family of glycosaminoglycans (GAGs) consisting of diversely sulfated repeating glucosamine-uronic acid disaccharide units, which play important roles in many important biological processes. The sulfate moieties in HS can significantly impact HS functions. Sulfatases are a class of enzymes that can cleave the sulfates from HS, thus modulating their activities. Sulfatases have been shown to play important roles in various pathophysiological conditions, including proliferation and migration of cancer cells, lysosomal diseases, congenital anomalies, and bacterial pathogenesis. In this review, following a general introduction on sulfatase, their enzymatic mechanism is discussed. Subsequently, their substrate scope is presented. The understanding of these molecular determinants has aided the rational design of inhibitors that mimic natural sulfated substrates. Efforts in developing a wide range of sulfatase inhibitors are summarized. Such inhibitors, including sulfamate analogs, can provide valuable insights into the sulfatase functions and provide leads as potential therapeutics targeting sulfatase-related diseases such as cancer.

Tin monosulfide (SnS) has attracted growing attention due to its environmentally benign constituents and natural abundance. Of particular interest is the metastable cubic phase π-SnS, first identified in 2015, which exhibits promising optoelectronic properties, including high hole mobility, a strong absorption coefficient exceeding 10⁴ cm⁻¹, and a tunable bandgap in the range of 1.5–1.8 eV. Various solution-based and gas-phase synthesis techniques have been employed to fabricate π-SnS thin films and nanocrystals. These synthesis methods and their parameters critically influence the resulting microstructure and electronic characteristics of π-SnS. This review provides a comprehensive and up-to-date overview of the synthesis strategies for π-SnS, pointing out to their impact on phase stability, material properties, and highlighting potential applications.

Capsular polysaccharides from a range of bacteria, notably campylobacters, possess 6-deoxy-heptose residues. Synthetic fragments of these polysaccharides have myriad applications in both fundamental and applied research, but few efficient routes for accessing these monosaccharides in a form suitable for glycosylation reactions are available. The synthesis of thioglycosides of 6-deoxy-d-manno-, 6-deoxy-d-talo-, and 6-deoxy-d-altro-heptoses from a single commercially available and inexpensive monosaccharide, methyl α-d-mannopyranoside, is reported here. The route involves C-6 homologation and, in some cases, configurational inversion at C-3 or C-4. These routes provide access to glycosyl donors of three of the four naturally occurring 6-deoxy-d-heptopyranoses, complementing previous work that has provided glycosyl donors of fourth such monosaccharide, 6-deoxy-d-ido-heptopyranose.