[This retracts the article DOI: 10.1039/D5RA09190J.].
[This retracts the article DOI: 10.1039/D5RA09190J.].
The hybridization approach was employed to design a single pharmacophore based on the conjugation of paracetamol with thiazole derivatives, yielding thiazole-paracetamol hybrid derivatives 4-11 that utilize a linker from hydrazone (-C[double bond, length as m-dash]N-NH) and azo (-N[double bond, length as m-dash]N-) linkers, serving as the hydrogen bond donor/acceptor binding site. The structure of the designed derivatives was fully characterized and confirmed using analytical data (IR, 1H NMR, and 13C NMR), and elemental analysis. The anti-inflammatory potential of the synthesized hybrids was evaluated using in vitro COX-2 enzymatic inhibition assay. The compounds exhibited moderate to excellent COX-2 inhibitory activity, with IC50 values ranging from 0.81 to 7.27 µM, compared with celecoxib (IC50 = 0.62 ± 0.02 µM). Among the synthesized derivatives, the 5-acetyl-4-methylthiazole candidate 8 emerged as the most potent inhibitor, displaying an IC50 value of 0.81 ± 0.02 µM, whereas the 5-ethoxycarbonyl-4-methylthiazole derivative 7 also demonstrated pronounced activity (IC50 = 1.35 ± 0.15 µM). The SAR analysis revealed that the 4-methylthiazole scaffold was more favorable for COX-2 inhibition than the corresponding 4-oxo-4,5-dihydrothiazole scaffold, while the introduction of compact carbonyl-containing substituents at the C-5 position markedly enhanced inhibitory potency. In contrast, aromatic substitution or incorporation of a 4-oxo-4,5-dihydrothiazole ring reduced activity. Furthermore, compounds 7 and 8 exhibited low-micromolar COX-1 inhibitory activity (IC50 = 0.89 ± 0.05 and 0.72 ± 0.02 µM, respectively), demonstrating dual activity toward COX-1/2 inhibition. In addition, compound 8 effectively suppressed the production of TNF-α and IL-6, with IC50 values of 1.48 ± 0.50 and 1.80 ± 0.35 µM, respectively, showing inhibitory activity comparable to that of celecoxib (IC50 = 1.40 ± 0.10 and 1.74 ± 0.20 µM, respectively). The docking process of the most promising derivative 8 demonstrated strong binding affinity and various types of interactions, including hydrogen bonding, π-π stacking, and hydrophobic interactions (π-alkyl and alkyl). In addition, ADMET prediction indicated a favorable pharmacokinetic profile and acceptable toxicity levels. These findings identify compound 8 as a promising lead candidate for the development of next-generation anti-inflammatory agents with dual cyclooxygenase inhibitory and immunomodulatory properties.
Photoelectrochemical water splitting using semiconductor materials is a viable approach to produce green hydrogen (H2). CuBi2O4 is a promising option because of its high redox potential and advantageous band gap; however, its use is hindered by significant charge carrier recombination and inadequate interfacial contact. We synthesized CuBi2O4 using a simple thermal method and examined the impact of polyvinyl alcohol on its structural and morphological characteristics. We observed a phase transformation from a mixed-phase CuBi2O4 to a highly efficient α-Bi2O3/β-Bi2O3/Cu2O heterostructure. The optimized heterostructure (α-Bi2O3/β-Bi2O3/Cu2O) showed a remarkable photocatalytic H2 evolution rate of 776 µmol g-1 compared with the pristine (CuBi2O4) structure, which achieved a rate of 166 µmol g-1. The exceptional photocatalytic H2 production of the heterogeneous sample arises from the efficient charge transfer mechanism and separation of photogenerated electron-hole pairs facilitated by the interfaces produced between the distinct phases. The enhanced transient photoresponse of α-Bi2O3/β-Bi2O3/Cu2O (9.76 µA) compared with that of the pure sample (5.13 µA) validates the effective generation and separation of photogenerated charge carriers resulting from the appropriate band alignment and in situ p-n junctions formed during the synthesis process. Furthermore, the electrochemical impedance spectra showed a reduced charge transfer resistance for the optimized heterostructure compared with that of the pure structure, thereby validating the superior photocatalytic H2 evolution of the heterostructure. Consequently, using the thermal approach establishes a simple synthesis route for heterogeneous catalysts with exceptional H2 evolution performance. Moreover, this study advances the development of H2 technology by providing a cost-effective strategy for designing efficient catalysts.
The synthesis routes, crystal and molecular structures, and controlled thermal decomposition reactions of two [pentamminecobalt(iii) compounds having a coordinated chromate ion, [Co(NH3)5CrO4]Cl (compound 1) and [Co(NH3)5CrO4]2CrO4 (compound 2) were studied experimentally. Quantum chemical optimizations and QTAIM calculations were performed for compounds 1 and 2, and the selected Bond Critical Points (BCPs) properties were discussed. The extended hydrogen-bond network between the coordinated chromate ions and ammonia ligands acts as reactive redox reaction centres, and both compounds show solid-phase quasi-intramolecular redox reactions with the formation of Co[Co0.5Cr1.5O3.75] and Co[Co0.2Cr1.8O3.90] nanosized regular spinels with nominal Co : Cr = 1 : 1 and 2 : 3 molar ratios, respectively. The tetrahedral positions of these spinels are filled with CoII ions. The octahedral positions of 2 : 3 and 1 : 1 spinels prepared in air are filled CrIII and mainly with CoIII ions. The 2 : 3 spinel prepared under N2 shows a similar distribution of ions, whereas the 1 : 1 spinel prepared under N2 contains only CoII ions at T-4, and CrIII, CoIII, and CoII ions at the OC-6 positions, resulting in a strongly defective structure. The position of the chromate ions (inner-sphere coordinated or outer-sphere non-coordinated) plays an important role in the quasi-intramolecular redox reactions and thermal decomposition characteristics of compounds 1 and 2. The inner-sphere coordinated chromate ions of both compounds took part in redox reactions with their own coordinated ammonia only after the loss of the fifth ammonia, in an endothermic ligand-releasing and an exothermic redox reaction mediated by the outer-sphere chromate ion for compounds 1 and 2, respectively. The cobalt(iii) content of both complexes is also reduced completely to cobalt(ii). These spinels were proven to be active catalysts in the visible-light-driven photocatalytic oxidation of rhodamine B with H2O2.
Surface functionalization provides an effective approach for tailoring the electrochemical properties of MXenes for lithium-ion battery applications. In this study, density functional theory (DFT) calculations were performed to investigate the effect of sulfur (S) and nitrogen (N) terminations on the lithium-storage performance of Ti2C MXene. Pristine Ti2C together with S-terminated (Ti2CS2) and N-terminated (Ti2CN2) monolayers were investigated by evaluating their structural stability, electronic properties, Li adsorption, diffusion behavior, open-circuit voltage and theoretical specific capacity. All three monolayers are energetically stable and retain their metallic character after lithiation, ensuring continuous electronic conductivity during battery operation. Surface functionalization increases the maximum Li atoms from x max = 2 in Li x Ti2C to x max = 4 in both Li x Ti2CS2 and Li x Ti2CN2 resulting in theoretical specific capacities of 497.5, 623.7, and 789.7 mAh g-1, respectively. The calculated Li-ion diffusion barriers of 0.24, 0.28 and 0.32 eV, together with the favorable open-circuit voltages (OCV) 0.87-0.08 V, 0.81-0.04 V and 0.68-0.02 V for Ti2C, Ti2CS2, and Ti2CN2 respectively, indicating fast Li-ion transport. Overall, sulfur and nitrogen terminations significantly improve the lithium-storage characteristics of Ti2C MXene, with Ti2CN2 exhibiting the highest theoretical capacity and Ti2CS2 offering a favorable balance between capacity and Li-ion mobility.
The rational integration of complementary two-dimensional (2D) semiconductors into van der Waals (vdW) heterostructures provides an effective route for engineering interfacial electronic and optoelectronic properties. Herein, we systematically investigate the GeCH/HfSO vdW heterostructure by first-principles calculations, with particular emphasis on the roles of interfacial stacking, Janus polarization, and biaxial strain. The optimized heterostructure exhibits weak vdW interlayer coupling, together with dynamical and thermal stability. The electronic structure reveals a type-II band alignment, with the valence-band maximum predominantly localized on GeCH and the conduction-band minimum on HfSO. The heterostructure also exhibits enhanced broadband optical absorption with coefficients on the order of 105 cm-1. More importantly, biaxial strain enables effective control of the band alignment, inducing a transition from type-I to type-II, while tensile strain continuously enhances the theoretical estimated photovoltaic conversion efficiency from 2.23% at zero strain to 28.60% at ε = +10%. These results establish GeCH/HfSO as a mechanically tunable vdW heterostructure with strong interfacial charge-separation capability and promising potential for next-generation optoelectronic and solar-energy conversion applications.
Controlling particle size is essential in solid-state synthesis, yet powder grinding remains a critical and largely unresolved challenge in self-driving laboratories. Here, we present a robotic mortar-based grinding system integrated with structure-borne acoustic emission (AE) sensing for autonomous powder processing. By measuring high-frequency elastic waves transmitted through the mortar, the proposed approach enables robust AE acquisition in standard laboratory environments without specialized acoustic facilities and provides a practical basis for particle-size-dependent feedback and autonomous stopping. We model AE-derived total spectral power as a monotonic function of particle size using monotone Bernstein polynomial regression, enabling size-dependent threshold design for grinding termination. Using this threshold-based stopping strategy, autonomous grinding experiments on NaCl and citric acid demonstrate reliable size-controlled processing. In contrast, monosodium glutamate exhibits degraded threshold reliability at intermediate target sizes, where AE fluctuations approach the noise floor. These results reveal material-dependent regimes in which AE-based feedback is effective only when sufficient signal-to-noise ratio is maintained, thereby clarifying the intrinsic limitations of AE-driven autonomous powder processing in solid-state self-driving laboratories.
The sensitive determination of trace As(iii) in environmental waters remains challenging, despite the availability of sophisticated instrumental techniques. Herein, a free-standing solid-state fluorescence sensing film was fabricated by immobilizing a MIL-101(Fe)@CQDs composite within a UV-curable polymer matrix. Structural, morphological, optical, and surface analyses using FTIR, XRD, UV-Vis spectroscopy, BET, SEM/STEM, DLS, and XPS supported the formation of the composite and its incorporation into the polymer network. The synthesized CQDs exhibited a photoluminescence quantum yield of 19.2 ± 3.2% (n = 3). Quantitative determination was based on the fluorescence-intensity difference (ΔI = I 0 - I). The calibration response was linear over 4.44 × 10-9-6.67 × 10-8 mol L-1 (R 2 = 0.9919), with an LOD of 1.49 × 10-9 mol L-1 and a calculated LOQ of 4.97 × 10-9 mol L-1. The method showed high tolerance toward the tested potentially interfering species, including As(v), Sb(iii), Sb(v), carbonate, bicarbonate, phosphate, and common metal ions. Practical applicability was evaluated using environmental water samples and certified reference materials for arsenic, yielding recoveries of 101.3-104.6% with relative standard deviations below 5%. Results for environmental water samples were consistent with direct HG-AAS performed without a separate As(v)-to-As(iii) pre-reduction step; this comparison was used as supporting evidence of analytical consistency rather than as proof of exclusive As(iii) detection. The same sensing film was reused over 150 measurement/regeneration cycles, with a 1.4% difference between the first and final responses. The combined MIL-101(Fe), CQD, and UV-curable polymer platform therefore provides an easy-to-handle and reusable solid-state format for trace As(iii) determination in aqueous samples.
In the search for potent bioactive compounds derived from medicinal plants, Garcinia parvifolia from East Kalimantan has demonstrated significant bioactivity consistent with established scientific criteria. Bioassay-guided isolation of the fruit extract resulted in two new depsidones named methyl garcidepsidone B (1) and parvifoliricodone A (6), two known analogues, a phloroglucinol, and a furfural derivative. Their structures were determined by spectroscopic techniques. The isolated compounds were subjected to assessments for their potential antidiabetic effects through an α-glucosidase inhibition assay, anti-tyrosinase activity, and antioxidant properties. Out of the isolated compounds, methyl garcidepsidone B (1) was the most potent inhibitor against α-glucosidase compared with acarbose as a positive standard. In the antioxidant assay, all isolated compounds showed significant free radical scavenging activity against ABTS, with the exception of compound 4. Regarding tyrosinase inhibitory activity, all isolated compounds exhibited low enzyme inhibition activity. Additionally, in silico molecular docking studies showed that compounds 1-3 exhibited favorable conformation and binding affinities within the enzymatic pockets of α-glucosidase. These findings indicate that the indigenous G. parvifolia fruit may serve as a natural source of antidiabetic, antioxidant, and anti-tyrosinase compounds, with potential for further pharmacological investigation.
Layered LiCoO2 thin-film (LCO) cathodes are attractive for lithium-ion microbatteries, but their use is constrained by structural instability, modest rate capability, and progressive capacity loss. In this work, we show that spatially graded Ni incorporation, achieved via controlled RF/DC co-sputtering, provides a promising strategy to tune structural and electrochemical limitations in layered LiNi x Co1-x O2 (LNCO) thin film cathodes. Three architectures were developed: LCO, uniformly Ni-incorporated LNCO-0.25A, and gradient Ni-incorporated LNCO-G, the latter obtained by progressively increasing the Ni target current from 0.20 to 0.40 A during deposition, producing a depth-dependent Ni distribution. XRD and Raman analyses show that Ni incorporation is accompanied by sharper reflections and reduced Raman peak broadening, consistent with improved local structural order. Cross-sectional HAADF-STEM and STEM-EDS mapping confirm a dense microstructure and a continuous Ni gradient increasing progressively from the substrate interface toward the coating surface. Depth-resolved XPS shows that, although all films develop surface carbonate species upon air exposure, LNCO-G exhibits a reduced hydroxyl/carbonate contribution compared with LNCO-0.25A, which is consistent with a less hydrated near-surface chemistry. Electrochemically, LNCO-G delivers higher current densities (≈3-5× increase) and more defined high-voltage redox features than the uniformly incorporated counterpart. In a preliminary 10-cycle diagnostic test under an aggressive 1.0-4.9 V window, LNCO-G achieves an initial discharge capacity of ∼100-120 mAh g-1 at 0.5C and retains ∼55% of its capacity. This short, aggressive protocol was intentionally chosen as a materials-level screening test to amplify differences in polarization and early degradation among the three architectures. Post-cycling EIS shows a 59% reduction in charge-transfer resistance (67.7 Ω vs. 164.3 Ω) and a lower Warburg coefficient (21.3 vs. 44.1 Ω s-1/2) relative to LNCO-0.25A. These results demonstrate that compositional Ni grading is associated with a measurable performance advantage over the uniform incorporation strategy studied here, although the comparison is not composition-matched and therefore reflects combined effects of Ni content, distribution, and secondary-phase fraction. These findings identify spatial Ni grading as a promising route for tuning coupled structural, interfacial, and kinetic properties in sputtered LiCoO2-based thin-film cathodes.
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