ChemistryOpen最新文献

Tyrosine kinases regulate cellular growth, differentiation, and metabolism, and their dysregulation is implicated in malignancies, making them therapeutic targets. This study synthesizes novel 5-benzylidene hydantoin derivatives (24-38) via benzylation and condensation, characterized by nuclear magnetic resonance (NMR), mass spectrometry, and fourier-transform infrared (FTIR). Anticancer activity was evaluated against eight receptor tyrosine kinases at 10 μM. Six compounds-24 (34%), 25 (45%), 28 (57%), 32 (60%), 34 (49%), and 38 (56%)-show moderate HER2 inhibition (%enzyme activity ≤ 60%). Compound 38 additionally inhibits VEGFR2 (27%), PDGFRα (32%), and PDGFRβ (25%). Molecular docking reveals interactions with HER2 residues Met801, Leu726, Leu852, Phe1004, Val734, and Leu796, suggesting a structural basis for selectivity. The HER2-targeting derivatives demonstrate potential for development as novel HER2 inhibitors. Compound 38's multikinase inhibition resembles sunitinib, a clinically approved drug for renal cell carcinoma and gastrointestinal stromal tumors, highlighting its promise for broader kinase-targeted therapy. These findings underscore the therapeutic relevance of the 5-benzylidene hydantoin scaffold, warranting further optimization to enhance potency and selectivity against HER2 and other oncogenic kinases.

Ammonia is a promising carbon-free hydrogen carrier, but incomplete ammonia dehydrogenation (cracking) generates atmospheric emissions of NO_x, a potent greenhouse gas. Additionally, incomplete cracking of ammonia leads to regulatory challenges in nuclear and fusion power, where tritiated ammonia (NT₃) emissions are strictly controlled. Therefore, we report the use of low-temperature ammonia dehydrogenation catalysts (3%Ru/1%Y/12%K/Al₂O₃) in a palladium alloy H₂ permeation membrane for quantitative conversion of ammonia into hydrogen and nitrogen at industry-relevant conditions. This catalytic membrane reactor system achieved an astonishing effluent concentration of <1 ppm at 450°C under a 100% NH₃ stream, which is far beyond the 99.6% conversion target required for the adoption of ammonia as a vehicle fuel. The low-temperature ammonia dehydrogenation catalyst was tested in a packed bed reactor with NH₃ and ND₃ to both elucidate the reaction mechanism and to quantify the kinetic isotope effect of the membrane reactor. The rate-limiting step at temperatures relevant to the palladium membrane are isotope independent, indicating that the isotopologue content will not modify the desired reaction kinetics. By reducing emissions to below-trace levels with no additional separation, this work provides a path to greatly simplified and miniaturized ammonia cracking processes.

Sensors are devices that can detect and enumerate the physical and/or chemical aspects in real time. The generation of novel sensory materials for sensing/recognition of chemical entities are significant for protecting both the environment and humanity. This review article reveals the achievements made in the designed synthesis and molecular recognition of Hamilton-type receptors since first report by Hamilton in 1988 to till date. This is the first elaborative manuscript in which Hamilton receptor is being exposed in detail. This manuscript is divided into three parts, in which the first portion highlights the importance and urgency of molecular recognition along with the historic background of Hamilton receptor. Whereas, the middle section discloses potential applications of Hamilton receptor in sensing and recognition of barbiturate molecules, anions, neutral molecules, drug molecules, amino acids, and racemic guest molecules. Additionally, this portion also covers the exciting applications of these receptors in the domain of rotaxanes and supramolecular catalysis. The final section highlights the future aspects of Hamilton receptor. The authors believe that this review will be useful to the inspiring researchers around the world thereby, boosting the field of receptors in the territory of supramolecular chemistry and other domains of scientific fields.

The exploration of green chemistry approaches for novel nanoparticles derived from microalgae presents a promising frontier in the realm of biomedical applications, harnessing the unique properties of these microorganisms for innovative solutions in healthcare. Microalgae, mainly due to their rapid growth rates and ability to synthesize diverse bioactive compounds, have become an environmentally friendly, green chemistry method to produce nanoparticles, overcoming current toxic chemical approaches. This review study aims to clarify the processes that underlie the biosynthesis of different microalgal species' nanoparticles and the following biomedical uses. The study investigates the manufacturing of copper, gold, iron, and silver nanoparticles and the optimization of other parameters, including pH and metal ion concentration. Characterization techniques such as UV-Vis spectroscopy, FTIR, TEM, and XRD revealed particle sizes ranging from 2 to 149 nm with distinct crystalline structures. Notably, microalgae-derived silver nanoparticles exhibited strong antioxidant activity (e.g., 77.01% DPPH and 88.12% ABTS scavenging at 500 µg mL^-1), potent antibacterial action (minimum inhibitory concentrations as low as 5 μg mL^-1 for Escherichia coli), and selective cytotoxicity against cancer cell lines (IC50 values: 25-30 µg mL^-1 for HeLa and MCF-7; as low as 0.16 μg mL^-1 for MCF7). These nanoparticles also demonstrated high biocompatibility, with minimal toxicity to normal human cells at effective concentrations. Overall, this study emphasizes how crucial it is to conduct further studies in this area to create safe and efficient nanomaterials for use in medical applications.

Azobenzene derivatives, which show light-induced reversible trans↔cis isomerization, have gained increasing attention in the area of protein science. p-(Phenylazo)-L-phenylalanine (Pap) was recently employed to enable the light-controlled affinity purification of biosynthetic proteins as part of the Azo-tag. Specific supramolecular complex formation with immobilized α-cyclodextrin (α-CD) groups is mediated by the Pap side chain in its low-energy trans-configuration, whereas photoisomerization to the cis-state leads to immediate dissociation. Here, we describe the X-ray crystallographic analysis of super-folder green fluorescent protein (sfGFP) displaying Pap at amino acid position 39 on its surface in complex with α-CD. While this experimental structure generally confirms the mode of host-guest interaction predicted by molecular modeling, there are two unexpected observations: (i) the conically shaped α-CD binds with its narrow end toward the aminoacyl moiety of Pap, despite appearing sterically more demanding, and (ii) the azobenzene side chain shows a considerably twisted conformation of its two phenyl rings, which contrasts with the fully coplanar arrangement usually anticipated for unmodified azobenzene and its chemical derivatives. Thus, this crystal structure of the photoswitchable noncanonical amino acid Pap (also known as AzoF or AzoPhe) provides valuable insight for future molecular engineering endeavors to endow proteins with light-controllable functions.

Nanocrystalline NiFe₂O₄ was synthesized using high-energy ball milling. The effect of milling time on structural and magnetic properties was investigated. X-ray diffraction results revealed a progressive transformation from mixed NiO-Fe₂O₃ precursor phases to a single-phase cubic spinel NiFe₂O₄ structure with crystallite sizes ranging from 33.64 to 41.17 nm. The scanning electron microscopy showed small grains attaching to big grains for 1 h milled sample. The big grains disappear with increasing milling time. Homogeneous nanoparticles, spherically shaped and agglomerated nanoparticles, were observed for samples that were milled for 5, 10, and 15 h. Energy-dispersive X-ray spectroscopy confirmed the presence of all expected elements. The nature of M-H loops for all the samples shows soft ferromagnetic behavior. The Electron spin resonace (ESR) results revealed the reduction of resonance field with increasing milling time. The g-values increased with milling time. The obtained high g-values make NiFe₂O₄ oxides suitable for applications in high-frequency devices. The spin-spin (τ₁) relaxation time decreased with increasing milling, time while the spin-lattice (τ₂) showed improvement.

Cancer is a leading cause of mortality worldwide, which has led to further research in developing more effective therapeutics. We synthesized amphipathic cationic peptides incorporating 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic acid) into their backbones to explore their potential anticancer properties. The MCF-7 cell line was selected to evaluate cell viability, inhibition percentage, and cytotoxic effects of the synthesized decapeptides. The results suggested DEC-1 (IC₅₀ = 3.38 µM) to be the most potent candidate, showcasing antiproliferative activity similar to the standard drug tamoxifen (IC₅₀ = 2.68 µM). Structural characterization of the peptides confirmed the successful incorporation of Tic into the peptide backbones. The peptides were docked with xanthine oxidase (PDB ID: 2CKJ) and Nrf2 (Nuclear factor erythroid 2-related factor 2) inhibitor protein Keap-1 (PDB ID: 7Q6S), revealing strong binding interactions, particularly for DEC-1, having a binding score of nearly -8.864 kcal/mol-which is stronger than its reference ligand with Keap-1 protein-suggesting possible inhibitory roles in cancer cell proliferation and oxidative stress regulation. These promising findings indicate that the potent molecule DEC-1 can be taken for further studies and might lead to a potential therapeutic agent for cancer treatment.

Metal borides (MBs) emerge as a versatile class of nanomaterials, featuring high stability and bifunctional Lewis-acidic/basic active sites. Despite these properties, their applications in CN bond formation are less explored. Herein, we report the first systematic use of M₂B-type boride nanoparticles as efficient and magnetically recoverable catalysts for the condensation of aldehydes with p-toluenesulfonamide under mild conditions. The synthesized CoZnB-NPs exhibit partially oxidized and hydroxylated surfaces with Lewis-acidic (B/Zn) and Lewis-basic (Co) sites, where the synergistic interaction between Co and Zn centers facilitates charge transfer and stabilizes reactive intermediates. A series of mono- and bimetallic boride NPs are synthesized via aqueous NaBH₄ reduction and comprehensively characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). CoZnB-NPs achieve yields of up to 93% within 1 h using an optimal catalyst loading of 3 mg in toluene, and demonstrate excellent magnetic recoverability and stability. This study highlights MB-NPs as a surface-engineered, high-performance platform for selective CN bond formation, providing insights into the design of bimetallic boride nanocatalysts for sustainable catalysis.

Heat-shock protein 70 (Hsp70) is a ubiquitous stress chaperone whose over-expression confers treatment resistance in many cancers. Recent structural and mechanistic work has uncovered an unexpected survival circuit: the proapoptotic BH3-only protein Bim binds a nucleotide-sensitive groove on the Hsp70 nucleotide-binding domain, sequestering itself from Bax/Bak while allosterically accelerating Hsp70's ATPase cycle and stabilizing oncogenic clients. This Hsp70-Bim protein-protein interaction (PPI) is enriched in tyrosine-kinase-inhibitor (TKI)-resistant chronic myeloid leukemia, endocrine-refractory breast cancer, glioblastoma, and other "chaperone-addicted" tumors, making it a selective vulnerability rather than a housekeeping liability. Early linear and stapled BH3 peptides proved the groove is drug-addressable but suffered from poor pharmacokinetics. A fragment-assisted screen then delivered a phenalene-dicarbonitrile chemotype, S1g-2, and optimized analogs that displace Bim with sub-micromolar potency, dismantle Hsp70-client hubs, and resensitize resistant xenografts to imatinib or tamoxifen without global proteostasis collapse. Orally bioavailable wedges thus convert a seemingly flat chaperone surface into an actionable checkpoint. This review integrates structural biology, assay technology, and medicinal chemistry to chart the rise of Hsp70-Bim inhibitors, evaluates combination strategies with BH3 mimetics, TKIs, and proteasome inhibitors, and highlights remaining challenges-cross-isoform breadth, species-relevant toxicology, biomarker-guided dosing, and potential impacts on antiviral immunity. Future directions include covalent or macrocyclic wedges, degrader hybrids, and adaptive pulse-dose regimens guided by proximity-ligation assays. Collectively, chemical disarming of the Hsp70-Bim alliance exemplifies how precision targeting of chaperone PPIs can recalibrate apoptotic thresholds and unlock new therapeutic space in oncology.

Zinc oxide nanoparticles (ZnO NPs) have drawn some attention due to its antimicrobial properties and potential for their usage in biomedicine. ZnO NPs were synthesized using algal biomass filtrate, characterized subsequently, and the antimicrobial, antibiofilm, and cytotoxic activities of the ZnO NPs were evaluated. The synthesized ZnO NPs were characterized with fourier transform infrared, X-ray Diffraction, scanning electron microscopic, and transmission electron microscopy to analyze their morphological and compositional properties. Agar well diffusion, time-kill assays and antibiofilm experiments were conducted to assess antibacterial efficacy, while Artemia salina nauplii were used to evaluate cytotoxicity. It was found that ZnO NPs had hexagonal wurtzite crystal structure, uniform nanoscale morphology ranging 20-90 nm, and high phase purity. ZnO NPs exhibited potent antibacterial activity, further confirmed by molecular docking analysis. Strong antibiofilm efficacy, reducing biofilm biomass by up to 95%. Exceptional results were shown by wet lab and docking validation. The PBP2a protein of S. aureus showed a binding score of -7.7, indicating strong inhibition by the ZnO NPs. These nanoparticles exhibit a dose-dependent response, where minimal toxicity was observed at lower concentrations. This study highlights the potential of algae-mediated ZnO NPs as a green, sustainable antimicrobial platform that may mitigate the microbial resistance problem.