Monthly Archives: September 2023

Chiral Substitution on Spaced Cations Lead to Improved Properties and Reversible Phase Transition, Broadband Emission in Parent Compound (3APr)PbBr4

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Chiral Substitution on Spaced Cations Lead to Improved Properties and Reversible Phase Transition, Broadband Emission in Parent Compound (3APr)PbBr4

We report a multifunctional compound: (3APr)PbBr4 (1) (3APr=3-Pyrrolidinamine) and corresponding enantiomer R and S-(3APr)PbBr4 (R/S-2). Compound 1 show reversible solid-state phase transition, step-like dielectric anomaly and broadband yellow emission under ultraviolet light excitation. the R/S-2 display mirror image structural relationship, increases quantum yield and CD signal.


Abstract

Hybrid organic-inorganic perovskites (HOIP) due to their excellent optoelectronic properties and flexible structure have attracted enthusiastic interest. In particular, introducing chirality is a method to enhance compound performance. Herein, we report a multifunctional compound: (3APr)PbBr4 (1) (3APr=3-Pyrrolidinamine) and corresponding enantiomer R and S-(3APr)PbBr4 (R/S-2). Compound 1 show reversible solid-state phase transition, step-like dielectric anomaly and broadband yellow emission under uv light excitation. Accompany with phase transition, structure dimension transition from 2D to 1D without space group change. Through introduce chirality, the R/S-2 display mirror image 1D structural relationship, increased quantum yield from 3.43 % (1) to 13.65 % (R/S-2) and exhibits corresponding CD signals. Then combine to first-principles analysis, it was found that fluorescence is attributed to the formation of instantaneous defects during excitation, leading to the formation of self-trapped excitons (STEs). This finding will further promote the development of multifunctional compound and the study of chiral substitution enhance compound properties.

Comparative Analysis of Antioxidant, Anticholinesterase, and Antibacterial Activity of Microbial Chondroitin Sulfate and Commercial Chondroitin Sulfate

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Comparative Analysis of Antioxidant, Anticholinesterase, and Antibacterial Activity of Microbial Chondroitin Sulfate and Commercial Chondroitin Sulfate


Abstract

Chondroitin synthesis was performed using the recombinant Escherichia coli(C2987) strain created by transforming the plasmid pETM6-PACF-vgb, which carries the genes responsible for chondroitin synthesis, kfoA, kfoC, kfoF, and the Vitreoscilla hemoglobin gene (vgb). Then, Microbial chondroitin sulfate (MCS)’s antioxidant, anticholinesterase, and antibacterial activity were compared with commercial chondroitin sulfate (CCS). The antioxidant studies revealed that the MCS and CCS samples could be potential targets for scavenging radicals and cupric ion reduction. MCS demonstrated better antioxidant properties in the ABTS assay with the IC50 value of 0.66 mg than CCS. MCS showed 2.5-fold for DPPH and almost 5-fold for ABTS⋅+ (with a value of 3.85 mg/mL) better activity than the CCS. However, the compounds were not active for cholinesterase enzyme inhibitions. In the antibacterial assay, the Minimum inhibitory concentration (MIC) values of MCS against S. aureus, E. aerogenes, E. coli, P. aeruginosa, and K. pneumoniae (0.12, 0.18, 0.12, 0.18, and 0.18 g/mL, respectively) were found to be greater than that of CCS (0.42, 0.48, 0.36, 0.36, and 0.36 g/mL, respectively). This study demonstrates that MCS is a potent pharmacological agent due to its physicochemical properties, and its usability as a therapeutic-preventive agent will shed light on future studies.

Genipa americana L.: A New Phytochemical for White Hair Coloring

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Genipa americana L.: A New Phytochemical for White Hair Coloring


Abstract

This work describes a new hair dyeing methodology using a chemical reaction between geniposide, an iridoid glycoside extracted from the fruit of Genipa americana (geniposide extract, GE) and the amine group of hair keratin. The influence of reaction conditions (pH, temperature, and extract concentration) on the staining of hair fibers, color development, fiber morphology, and mechanical hair properties of black and white human hair samples, was evaluated before and after GE dyeing treatment. Eye contact safety of GE was also studied using HET-CAM. The treatment of white hair fibers using GE at 20 mg mL−1, temperature of 80 °C and pH 5.5 presented the greatest color change (ΔE=54.0). The higher pH influence was observed at pH 10.0 on white hair tresses (ΔE=6.8), using an GE concentration of 20 mg mL−1 and room temperature (25 °C). Treated samples showed marked changes on mechanical and morphological properties. The HET-CAM did not show any change, thus demonstrating that using GE is safe. In conclusion, the temperature and concentration of the extract were the variables that mostly influenced the color and hair damage. A new approach for hair dyeing was established where iridoids may potentially be useful as a natural hair dyeing.

Amine‐Functionalized Amyloid Aerogels for CO2 Capture

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Amine-Functionalized Amyloid Aerogels for CO2 Capture

Amyloid fibrils from β-lactoglobulin (BLG), lysozyme, and black bean protein were prepared and modified with aminosilane. Then, the amine-functionalized amyloid fibril-templated aerogels were synthesized to capture CO2 from a dilute atmosphere (~400 ppm CO2).


Abstract

Climate change caused by excessive CO2 emissions constitutes an increasingly dire threat to human life. Reducing CO2 emissions alone may not be sufficient to address this issue, so that the development of emerging adsorbents for the direct capture of CO2 from the air becomes essential. Here, we apply amyloid fibrils derived from different food proteins as the solid adsorbent support and develop aminosilane-modified amyloid fibril-templated aerogels for CO2 capture applications. The results indicate that the CO2 sorption properties of the aerogels depend on the mixing ratio of aminosilane featuring different amine groups and the type of amyloid fibril used. Notably, amine-functionalized β-lactoglobulin (BLG) fibril-templated aerogels show the highest CO2 adsorption capacity of 51.52 mg (1.17 mmol) CO2/g at 1 bar CO2 and 25.5 mg (0.58 mmol) CO2/g at 400 ppm; similarly, the CO2 adsorption capacity of chitosan-BLG fibril hybrid aerogels is superior to that of pure chitosan. This study provides a proof-of-concept design for an amyloid fibril-templated hybrid material facilitating applications of protein-based adsorbents for CO2 capture, including direct air capture.

Hydrogen Evolution of a Unique DNAzyme Composed of Cobalt‐Protoporphyrin IX and G‐Quadruplex DNA

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Molecular hydrogen (H2) is a clean and renewable fuel that has garnered significant interest in the search for alternatives to fossil fuels. Here, we constructed an artificial DNAzyme composed of cobalt-protoporphyrin IX (CoPP) and G-quadruplex DNA, possessing a unique H2Oint ligand between the CoPP and G-quartet planes. We show for the first time that CoPP-DNAzyme catalyzes photo-induced H2 production under anaerobic conditions with a turnover number (TON) of 1229 ± 51 over 12 h at pH 6.05 and 10°C. Compared with free-CoPP, complexation with G-quadruplex DNA resulted in a 4.7-fold increase in H2 production activity. The TON of the CoPP-DNAzyme revealed an optimal acid-base equilibrium with a pKa value of 7.60 ± 0.05, apparently originating from the equilibrium between Co(III)-H– and Co(I) states. Our results demonstrate that the H2Oint ligand can augment and modulate the intrinsic catalytic activity of H2 production catalysts. These systems pave the way to using DNAzymes for H2 evolution in the direct conversion of solar energy to H2 from water.

Calculation of the moscovium ground‐state energy by quantum algorithms

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Calculation of the moscovium ground-state energy by quantum algorithms

The possibility of simulating the electronic structure of ions and atoms by quantum algorithms is studied in the example of the moscovium atom. Among all tested approaches, the variational quantum eigensolver with the problem-inspired ansatz and Adam optimizer demonstrated the highest level of scalability while simultaneously providing a high level of accuracy for the ground-state energy.


Abstract

We investigate the possibility to calculate the ground-state energy of the atomic systems on a quantum computer. For this purpose we evaluate the lowest binding energy of the moscovium atom with the use of the iterative phase estimation and variational quantum eigensolver (VQE). The calculations by the VQE are performed with a disentangled unitary coupled cluster ansatz and with various types of hardware-efficient ansatze. The optimization is performed with the use of the Adam and quantum natural gradients procedures. The scalability of the ansatze and optimizers is tested by increasing the size of the basis set and the number of active electrons. The number of gates required for the iterative phase estimation and VQE is also estimated.

Expanding the Substrate Scope of N‐ and O‐Methyltransferases from Plants for Chemoselective Alkylation

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Expanding the Substrate Scope of N- and O-Methyltransferases from Plants for Chemoselective Alkylation**

Chemoselective S-adenosyl-l-methionine (SAM)-dependent methyltransferases (MTs) are a promising alternative to traditional synthetic methylation reactions. In presence of multiple nucleophiles, the enzymatic transfer of the carbon fragment is highly chemoselective for N- and O-MTs. Besides methylation, the generation of SAM derivatives enables the transfer of altered groups onto the substrates increasing the pool of products.


Abstract

Methylation reactions are of significant interest when generating pharmaceutically active molecules and building blocks for other applications. Synthetic methylating reagents are often toxic and unselective due to their high reactivity. S-Adenosyl-l-methionine (SAM)-dependent methyltransferases (MTs) present a chemoselective and environmentally friendly alternative. The anthranilate N-MT from Ruta graveolens (RgANMT) is involved in acridone alkaloid biosynthesis, methylating anthranilate. Although it is known to methylate substrates only at the N-position, the closest relatives with respect to amino acid sequence similarities of over 60 % are O-MTs catalysing the methylation reaction of caffeate and derivatives containing only hydroxyl groups (CaOMTs). In this study, we investigated the substrate range of RgANMT and a CaOMT from Prunus persica (PpCaOMT) using compounds with both, an amino- and hydroxyl group (aminophenols) as possible methyl group acceptors. For both enzymes, the reaction was highly chemoselective. Furthermore, generating cofactor derivatives in situ enabled the transfer of other alkyl chains onto the aminophenols, leading to an enlarged pool of products. Selected MT reactions were performed at a preparative biocatalytic scale in in vitro and in vivo experiments resulting in yields of up to 62 %.

Nickel‐asparagine complex fixed on a magnetic substrate as a precursor for preparing substituted acridines

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Nickel-asparagine complex fixed on a magnetic substrate as a precursor for preparing substituted acridines


In this work, an efficient, novel, retrievable, and magnetic heterogeneous nanocatalyst, Fe3O4@CPTMS@Asp@Ni was successfully fabricated using Fe3O4 nanoparticles as the core that were coated with surfactant and 3-chloropropyltrimethoxysilan and deposited asparagine and nickel metal that can be used in multicomponent reactions for the synthesis of acridines derivatives with high yield in short reaction times. The virtue of obtained nanocatalyst was identified using transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, energy dispersive X-ray, Brunauer–Emmett–Teller, vibrating sample magnetometry, Raman, and thermogravimetric analysis. The X-ray diffraction analysis studies demonstrate that the average crystallite sizes of the prepared nanocatalyst are estimated to be about 45.4 nm. Also, the vibrating sample magnetometry measurement shows saturation magnetization values (Ms) of 7 emu/g for Fe3O4@CPTMS@Asp@Ni nanocatalyst. Also, after the synthesis steps, the application of the prepared nanocatalyst in the preparation of acridine-1,8(2H,5H)-diones has been investigated. Then to evaluate and assess the efficiency of the nanocatalyst as mentioned above, and its effect on the synthesis of divergent acridines via a one-pot, three-component condensation reaction of cyclic 1,3-dione, aryl glyoxal, with ammonium acetate in the water as green solvent was studied. Also, when investigating the reusability of this catalyst, it was observed that Fe3O4@CPTMS@Asp@Ni nanocatalyst could be reused at least five times without losing its efficiency. High efficiency, outstanding yields in quick intervals, easy separation using a magnetic field, and possessing reusability are significant benefits of the attained nanocatalyst.

Surface/Interface Engineering of Hierarchical MoO2/MoNi4@Ru/RuO2 Heterogeneous Nanosheet Arrays for Alkaline Water Electrolysis with Fast Kinetics

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Comprehensive Summary

Realizing the hydrogen economy by water electrolysis is an attractive approach for hydrogen production, while the efficient and stable bifunctional catalysts under high current densities are the bottleneck that limits the half-cell reactions of water splitting. Here, we propose an approach of hydrothermal and thermal annealing methods for robust MoO2/MoNi4@Ru/RuO2 heterogeneous cuboid array electrocatalyst with multiplying surface-active sites by depositing a monolayer amount of Ru. Benefiting from abundant MoO2/MoNi4@Ru/RuO2 heterointerfaces on Cu foam, effectively driving the alkaline water splitting with superior hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The synthesized MoO2/MoNi4@Ru/RuO2 has high HER activity, which realizes the working overpotentials of 48 mV at 50 mA cm-2, further achieving overpotentials of 230 mV for industry-level 1000 mA cm-2 in alkaline water electrolysis. Moreover, it also showed an enhanced OER activity than commercial RuO2 with a small overpotential of 280 mV at 200 mA cm-2 in alkaline media. When building an electrolyzer with electrodes of (-)MoO2/MoNi4@Ru/RuO2IIMoO2/MoNi4@Ru/RuO2 (+), a cell voltage of 1.63 V, and 1.75 V just requires to support the current density of 200 mA cm-2 and 500 mA cm-2 in alkaline water electrolysis, much lower than the electrolyzer of (-)Pt/CIIRuO2(+). This work demonstrates that MoO2/MoNi4@Ru/RuO2 heterogeneous nanosheet arrays are promising candidates for industrial water electrolysis applications, providing a possibility for the exploration of water electrolysis with a large current density.

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