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Structure engineering is a powerful tool for tuning various properties and making CoFe2O4 (CFO) a prime candidate for electrocatalyst applications, especially in improving the oxygen evolution reaction (OER) performance. In this work, we explored rhenium substituents to replace cobalt and iron atoms of the CFO and obtained significant differences with the same doping level. The sol–gel process was employed to prepare the nanoparticles of Co1−zRezFe2O4 and CoFe2−zRezO4 (z = 0, 0.05). A detailed structural evaluation using Mössbauer spectroscopy verified the pure phase cubic spinel-type structure with a noticeable change in morphology by substituting Re. The OER and electrochemical impedance spectroscopy (EIS) were performed and showed better performance in the Fe-site doped structure. To explain the differences in the OER performance of the samples, X-ray photoelectron spectroscopy (XPS) on all elements, low-temperature Raman, and the density of states simulated by density-functional theory (DFT) were performed. We found that Re actively changed the properties of the structures and the doping on Fe-site enabled more oxygen vacancy and a higher ratio of cations in octahedral sites, which led to enhanced catalytic performance. This work provides a deep insight into the mechanism that influences the OER properties with Re doped in different sites, indicating a promising application of CFO as a catalyst material. [ABSTRACT FROM AUTHOR]

Monoclinic bismuth vanadate (BiVO4) has emerged as an excellent optically active photoanode material due to its unique physical and chemical properties. Experiments reported that the low concentration of oxygen vacancies enhances the photoelectrochemical (PEC) activity of BiVO4, but the high concentration of oxygen vacancies decreases the charge carrier lifetime. Using time-domain density functional theory and molecular dynamics, we have demonstrated that the distribution of oxygen vacancies has strong effects on the static electronic structure and nonadiabatic (NA) coupling of the BiVO4 photoanode. The localized oxygen vacancies create charge recombination centers within the band gap and enhance the NA coupling between the VBM and the CBM, resulting in fast charge and energy losses. By contrast, the discrete oxygen vacancies can eliminate the charge recombination centers and decrease the NA coupling between the VBM and the CBM, enhancing the PEC activity of monoclinic BiVO4. Our study suggests that the PEC performance of a photoanode can be improved by changing the distribution of oxygen vacancies. [ABSTRACT FROM AUTHOR]

The design of an efficient absorbent is the premise for recovery and resource utilization of hydrogen chloride (HCl) from its industrial tail gases. Herein, a series of 1-butyl-3-methylimidazolium chloride (BmimCl) based-deep eutectic solvents (DESs) were designed and the solubility behavior for HCl was studied in terms of their structure, basicity, free volume, intermolecular interaction energy, and absorption enthalpy. The relationship between the interaction energy and the phase change in the HCl dissolution process was explored in detail. BmimCl-TAA (thioacetamide) (1 : 1) shows high reversible solubility due to its high free volume, suitable absorption enthalpy, and closer H-bonding (HB) interactions between BmimCl and TAA or HCl. The dissolution mechanism of HCl and the dynamic evolution of the HB network were verified by FT-IR and NMR spectra and quantum chemical calculations. The results show that it is the competitive HB interaction that promotes the dissolution of HCl, reduces the absorption enthalpy, and renders a reversible absorption. Compared with BmimCl, the absorption enthalpy of HCl in BmimCl-TAA (1 : 1) is reduced by 25% and the reversible solubility increased 150%. The reversible solubility of HCl in BmimCl-TAA (1 : 1) is as high as 0.51 g g−1 (1.76 mol mol−1) at 303.15 K and 101.3 kPa, and the absorbent can be regenerated facilely by heating under reduced pressure. This work provides new insights into the rational design of DES for efficient and reversible absorption of HCl and other polar gases. [ABSTRACT FROM AUTHOR]

We developed a novel self-assembled DNA nanostructure for anticancer drug delivery. The resulting nanostructure was able to specifically target cancer cells and release the loaded drug at pH 5.0. More importantly, the drug-loaded DNA nanostructure effectively circumvented doxorubicin resistance of human lung adenocarcinoma epithelial cancer cells. [ABSTRACT FROM AUTHOR]

Monoclinic bismuth vanadate (BiVO 4 ) has emerged as an excellent optically active photoanode material due to its unique physical and chemical properties. Experiments reported that the low concentration of oxygen vacancies enhances the photoelectrochemical (PEC) activity of BiVO 4 , but the high concentration of oxygen vacancies decreases the charge carrier lifetime. Using time-domain density functional theory and molecular dynamics, we have demonstrated that the distribution of oxygen vacancies has strong effects on the static electronic structure and nonadiabatic (NA) coupling of the BiVO 4 photoanode. The localized oxygen vacancies create charge recombination centers within the band gap and enhance the NA coupling between the VBM and the CBM, resulting in fast charge and energy losses. By contrast, the discrete oxygen vacancies can eliminate the charge recombination centers and decrease the NA coupling between the VBM and the CBM, enhancing the PEC activity of monoclinic BiVO 4 . Our study suggests that the PEC performance of a photoanode can be improved by changing the distribution of oxygen vacancies.

Enzymatic synthesis of selenium (Se)-enriched peptides is vital for their application in supplementing organic Se. However, the poor stability and reusability of the free enzyme impedes the reaction. In this work, a highly stable immobilized Alcalase was synthesized by immobilizing Alcalase on tannic acid (TA) and polyethyleneimine (PEI) modified Fe 3 O 4 nanoparticles (NPs). The optimal immobilization conditions for immobilized Alcalase were found at a TA/PEI (v/v) ratio of 1 : 1, pH of 10, and temperature of 40 °C, and the results from scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) characterization confirmed the successful immobilization of Alcalase. The results of an enzyme property test showed that immobilized Alcalase had higher thermal and pH stability than free Alcalase, and retained 61.0% of the initial enzyme activity after 10 repetitions. Furthermore, the organic Se content of Se-enriched peptide prepared through enzymatic hydrolysis of Cardamine violifolia (CV) protein with immobilized Alcalase was 2914 mg kg -1 , and the molecular weight was mainly concentrated in 924.4 Da with complete amino acid components. Therefore, this study proposes the feasibility of immobilized enzymes for the production of Se-enriched peptides., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

The first total synthesis of Palmarumycin BG1-3, BG5-6, C 1 and Guignardin E (1-7) were achieved by the same intermediate Palmarumycin C 2 through a N -benzyl cinchoninium chloride-catalyzed epoxidation, an organoselenium-mediated reduction, and a cerium(iii) chloride hydrate-promoted regioselective ring-opening and elimination of cyclic α,β-epoxy ketone as the key steps via 6-7 step routes using 1,8-dihydroxynaphthalene (DHN) and 5-methoxytetralone as the starting materials in overall yields of 1.0-17.4%, respectively. Their structures and absolute configurations were characterized and determined by 1 H, 13 C NMR, IR, HR-ESI-MS and X-ray diffraction data. These compounds displayed significant inhibition activities against HCT116, U87-MG, HepG2, BGC823 and PC9 cell lines., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

As a major component of green tea, (-)-epigallocatechin-3-gallate (EGCG) has attracted interest from scientists owing to its potential to combat a variety of human diseases including abnormal glucose metabolism in obesity and diabetes. This study aims to (1) evaluate the molecular mechanism of EGCG in starch digestion before EGCG absorption; (2) investigate the link between PXR/CAR-mediated phase II metabolism and glucose homeostasis after EGCG is transported to small intestine and liver. EGCG suppressed starch hydrolysis both in vitro and in vivo. Molecular simulation results demonstrated that EGCG could bind to the active site of α-amylase and α-glucosidase, acting as an inhibitor. In addition, the anti-diabetic action of EGCG was investigated in high fat diet and STZ-induced type 2 diabetes. EGCG improved glucose homeostasis and inhibited the process of gluconeogenesis (PEPCK and G-6-Pase) and lipogenesis (SREBP-1C, FAS and ACC1) in the liver. Meanwhile, EGCG treatment activated PXR/CAR, accompanied by upgrading PXR/CAR-mediated phase II drug metabolism enzyme expression in small intestine and liver, involving SULT1A1, UGT1A1 and SULT2B1b. Dietary polyphenol EGCG could serve as a promising PXR/CAR activator and therapeutic intervention in diabetes.

Compounds in Fructus Gardeniae have been shown to possess a wide array of biological activities. However, Gardenia oil extracted from its fruit is less reported and its composition remains uncertain. To completely characterize lipophilic compounds in Gardenia oil, three conventional extraction (CE) and ultrasound-assisted extraction (UAE) methods were investigated. The oil extraction yield obtained by UAE was 51.8% higher than that acquired by cold-pressed extraction (CPE). The fatty acid profile in UAE oil with different solvents was characterized by GC-MS. Petroleum ether was observed to be an ideal solvent with 8.59% extraction yield and 78.88% recovery rate and with a ratio of 3.11 of unsaturated fatty acids to saturated fatty acids. Response surface methodology (RSM) with Box-Behnken Design (BBD) was applied to optimize conditions in UEA of oil to maximize extraction yield. Furthermore, the bioactive components in oil extracted by UAE were qualitatively identified and quantified by HPLC-DAD/ESI-MS(2) and HPLC-DAD analysis. The eight compounds in Gardenia oil, including geniposide, trans/cis-crocin-1, crocin-2, crocin-3, crocin-4, and trans/cis-crocetin, were structurally revealed. The corresponding transfer rates of the bioactive components showed that the lipophilic trans/cis-crocetin could be completely transferred from fruit to oil, with the highest concentration of 11.38 μg g(-1) oil among all compounds quantified. These findings could deliver potential application to a large-scale production of functional Gardenia oil whose bioactive components possess health benefits.