Metal-Organic Gel Leading to Customized Magnetic-Coupling Engineering in Carbon Aerogels for Excellent Radar Stealth and Thermal Insulation Performances.

Metal-organic gel (MOG) derived composites are promising multi-functional materials due to their alterable composition, identifiable chemical homogeneity, tunable shape, and porous structure. Herein, stable metal-organic hydrogels are prepared by regulating the complexation effect, solution polarity and curing speed. Meanwhile, collagen peptide is used to facilitate the fabrication of a porous aerogel with excellent physical properties as well as the homogeneous dispersion of magnetic particles during calcination. Subsequently, two kinds of heterometallic magnetic coupling systems are obtained through the application of Kirkendall effect. FeCo/nitrogen-doped carbon (NC) aerogel demonstrates an ultra-strong microwave absorption of - 85 dB at an ultra-low loading of 5%. After reducing the time taken by atom shifting, a FeCo/Fe3O4/NC aerogel containing virus-shaped particles is obtained, which achieves an ultra-broad absorption of 7.44 GHz at an ultra-thin thickness of 1.59 mm due to the coupling effect offered by dual-soft-magnetic particles. Furthermore, both aerogels show excellent thermal insulation property, and their outstanding radar stealth performances in J-20 aircraft are confirmed by computer simulation technology. The formation mechanism of MOG is also discussed along with the thermal insulation and electromagnetic wave absorption mechanism of the aerogels, which will enable the development and application of novel and lightweight stealth coatings.

Synthesis, Crystal Structure, Spectral Characterization and Antifungal Activity of Novel Phenolic Acid Triazole Derivatives.

At present, phenolic acid derivatives and triazole derivatives have a good antifungal effect, which has attracted widespread attention. A series of novel phenolic acid triazole derivatives were synthesized, and their structures were characterized by IR, MS, NMR, and X-ray crystal diffraction. Compound methyl 4-(2-bromoethoxy)benzoate, methyl 4-(2-(1H-1,2,4-triazol-1-yl) ethoxy)benzoate, 4-(2-(1H-1,2,4-triazol-1-yl)ethoxy)benzoic acid and 4-(2-(1H-1,2,4-triazol-1-yl) ethoxy)-3-methoxybenzoic acid crystallize in the monoclinic system with space group P21/n, the monoclinic system with space group P21, the monoclinic system with space group P21 and the orthorhombic system with space group Pca21, respectively. At a concentration of 100 µg/mL and 200 µg/mL, the antifungal activity against seven plant pathogen fungi was determined. Compound methyl 4-(2-bromoethoxy)benzoate has the best inhibitory effect on Rhizoctonia solani AG1, and the inhibitory rate reached 88.6% at 200 µg/mL. The inhibitory rates of compound methyl 4-(2-(1H-1,2,4-triazol-1-yl) ethoxy)benzoate against Fusarium moniliforme and Sphaeropsis sapinea at a concentration of 200 µg/mL were 76.1% and 75.4%, respectively, which were better than that of carbendazim.

Design, Synthesis and Bioactivity Evaluation of Coumarin-BMT Hybrids as New Acetylcholinesterase Inhibitors.

Coumarin possesses the aromatic group and showed plentiful activities, such as antioxidant, preventing asthma and antisepsis. In addition, coumarin derivatives usually possess good solubility, low cytotoxicity and excellent cell permeability. In our study, we synthesized the compound bridge methylene tacrine (BMT), which has the classical pharmacophore structure of Tacrine (THA). Based on the principle of active substructure splicing, BMT was used as a lead compound and synthesized coumarin-BMT hybrids by introducing coumarin to BMT. In this work, 21 novel hybrids of BMT and coumarin were synthesized and evaluated for their inhibitory activity on AChE. All obtained compounds present preferable inhibition. Compound 8b was the most active compound, with the value of Ki as 49.2 nM, which was higher than Galantamine (GAL) and lower than THA. The result of molecular docking showed that the highest binding free energy was -40.43 kcal/mol for compound 8b, which was an identical trend with the calculated Ki.

Preparation of Furfural From Xylose Catalyzed by Diimidazole Hexafluorophosphate in Microwave.

In this work, functionalized alkyl imidazolium hexafluorophosphate ILs were synthesized and characterized; then, they were applied in the conversion of xylose to furfural under the microwave method. The results showed that when CnMF was used as a catalyst, an acidic environment was provided to promote the formation of furfural. In addition, the heating method, the solvent, and the different structures of cations in the ionic liquid influenced their catalytic activity. In an aqueous solution, the yield of furfural obtained using the microwave method was better than that of the conventional heating method, and the catalytic activity of diimidazole hexafluorophosphate was better than that of monoimidazole. Meanwhile, for the diimidazole hexafluorophosphate, the change of the carbon chain length between the imidazole rings also slightly influenced the yield. Finally, the optimal yield of 49.76% was obtained at 205°C for 8 min using 3,3'-methylenebis(1-methyl-1H-imidazol-3-ium), C1MF, as a catalyst. Mechanistic studies suggested that the catalytic activity of C1MF was mainly due to the combined effect of POFn (OH)3-n and imidazole ring. Without a doubt, the catalytic activity of C1MF was still available after five cycles, which not only showed its excellent catalytic activity in catalyzing the xylose to prepare the biomass platform compound furfural but also could promote the application of functionalized ionic liquids.

Synthesis, in vitro inhibitory activity, kinetic study and molecular docking of novel N-alkyl-deoxynojirimycin derivatives as potential α-glucosidase inhibitors.

A series of novel N-alkyl-1-deoxynojirimycin derivatives 25 ∼ 44 were synthesised and evaluated for their in vitro α-glucosidase inhibitory activity to develop α-glucosidase inhibitors with high activity. All twenty compounds exhibited α-glucosidase inhibitory activity with IC50 values ranging from 30.0 ± 0.6 µM to 2000 µM as compared to standard acarbose (IC50 = 822.0 ± 1.5 µM). The most active compound 43 was ∼27-fold more active than acarbose. Kinetic study revealed that compounds 43, 40, and 34 were all competitive inhibitors on α-glucosidase with Ki of 10 µM, 52 µM, and 150 µM, respectively. Molecular docking demonstrated that the high active inhibitors interacted with α-glucosidase by four types of interactions, including hydrogen bonds, π-π stacking interactions, hydrophobic interactions, and electrostatic interaction. Among all the interactions, the π-π stacking interaction and hydrogen bond played a significant role in a various range of activities of the compounds.

Design, Synthesis, and Activity Evaluation of Novel N-benzyl Deoxynojirimycin Derivatives for Use as α-Glucosidase Inhibitors.

To obtain α-glucosidase inhibitors with high activity, 19 NB-DNJDs (N-benzyl-deoxynojirimycin derivatives) were designed and synthesized. The results indicated that the 19 NB-DNJDs displayed different inhibitory activities towards α-glucosidase in vitro. Compound 18a (1-(4-hydroxy-3-methoxybenzyl)-2-(hydroxymethyl) piperidine-3,4,5-triol) showed the highest activity, with an IC50 value of 0.207 ± 0.11 mM, followed by 18b (1-(3-bromo-4-hydroxy-5-methoxybenzyl)-2-(hydroxymethyl) piperidine-3,4,5-triol, IC50: 0.276 ± 0.13 mM). Both IC50 values of 18a and 18b were significantly lower than that of acarbose (IC50: 0.353 ± 0.09 mM). According to the structure-activity analysis, substitution of the benzyl and bromine groups on the benzene ring decreased the inhibition activity, while methoxy and hydroxyl group substitution increased the activity, especially with the hydroxyl group substitution. Molecular docking results showed that three hydrogen bonds were formed between compound 18a and amino acids in the active site of α-glucosidase. Additionally, an arene‒arene interaction was also modelled between the phenyl ring of compound 18a and Arg 315. The three hydrogen bonds and the arene‒arene interaction resulted in a low binding energy (-5.8 kcal/mol) and gave 18a a higher inhibition activity. Consequently, compound 18a is a promising candidate as a new α-glucosidase inhibitor for the treatment of type Ⅱ diabetes.

Formation mechanism of low-density lipoprotein gel induced by NaCl.

Salted eggs, which are a traditional Chinese egg product, are favored by Chinese consumers and have become very popular in other Asian countries due to their unique features such as "fresh, fine, tender, loose, gritty and oily texture." In order to illuminate the forming process of salted egg, the gelation behavior and mechanism of low-density lipoprotein (LDL) induced by NaCl were investigated using marinated model outside the eggshell. Results showed that as the salting proceeded, the moisture content exhibited a decreasing trend. The NaCl content, oil exudation, hardness, and surface hydrophobicity showed constantly increasing trends. In the early stages of salting, the size of the LDL particles, soluble protein content, and T21 increased, whereas T21 (with D2O), T22, and the free sulfhydryl content declined. In the later stages of salting, LDL formed a multiple composite aggregate gel structure with filamentous apoproteins and non-spherical lipid particles intertwined with each other. The soluble protein content and T23 (without D2O) decreased, whereas T21 (with D2O), T22 and the free sulfhydryl content increased. Fourier transform infrared spectroscopy revealed that the fresh LDL mainly consisted of α-helix and ß-sheet structures. After the gel becomes hardened, the LDL secondary structure was changed remarkably, characterized by the decrease of α-helix elements and increase of ß-sheet elements. The results suggested that the oil exudation of salted LDL gels was mainly due to LDL destruction and the release of components (apoproteins, phospholipids, and neutral lipids) facilitated by increased interactions between apoproteins and lipids.

Effects of salting treatment on the physicochemical properties, textural properties, and microstructures of duck eggs.

In order to illuminate the forming process of salted egg, the effects of the brine solution with different salt concentrations on the physicochemical properties, textural properties, and microstructures of duck eggs were evaluated using conventional physicochemical property determination methods. The results showed that the moisture contents of both the raw and cooked egg whites and egg yolks, the springiness of the raw egg yolks and cooked egg whites exhibited a decreasing trend with the increase in the salting time and salt concentration. The salt content, oil exudation and the hardness of the raw egg yolks showed a constantly increasing trend. Viscosity of the raw egg whites showed an overall trend in which it first deceased and then increased and decreased again, which was similar to the trend of the hardness of the cooked egg whites and egg yolks. As the salting proceeded, the pH value of the raw and cooked egg whites declined remarkably and then declined slowly, whereas the pH of the raw and cooked egg yolks did not show any noticeable changes. The effect of salting on the pH value varied significantly with the salt concentration in the brine solution. Scanning electron microscopy (SEM) revealed that salted yolks consist of spherical granules and embedded flattened porosities. It was concluded that the treatment of salt induces solidification of yolk, accompanied with higher oil exudation and the development of a gritty texture. Different salt concentrations show certain differences.

Synthesis of water soluble glycosides of pentacyclic dihydroxytriterpene carboxylic acids as inhibitors of α-glucosidase.

A series of compounds were synthesized by glycosylation of maslinic acid (MA) and corosolic acid (CA) with monosaccharides and disaccharides, and the structures of the derivatives were elucidated by standard spectroscopic methods including (1)H NMR, (13)C NMR and HRMS. The α-glucosidase inhibitory activities of all the novel compounds were evaluated in vitro. The solubility and inhibitory activity of α-glucosidase assays showed that the bis-disaccharide glycosides of triterpene acids possessed higher water solubility and α-glucosidase inhibitory activities than the bis-monosaccharide glycosides. Among these compounds, maslinic acid bis-lactoside (8e, IC50 = 684 µM) and corosolic acid bis-lactoside (9e, IC50 = 428 µM) had the best water solubility, and 9e exhibited a better inhibitory activity than acarbose (IC50 = 478 µM). However, most of glycosylated derivatives possessed lower inhibitory activities than the parent compounds, although their water solubility was enhanced obviously. Moreover, the kinetic inhibition studies indicated that 9e was a non-competitive inhibitor, and structure-activity relationships of the derivatives are also discussed.

Effects of alkaline concentration, temperature, and additives on the strength of alkaline-induced egg white gel.

Egg whites can undergo gelation at extreme pH. In this paper, the effects of NaOH concentration (1.5, 2, 2.5, and 3%), temperature (10, 20, 30, and 40°C), and additives (metallic compounds, carbohydrates, stabilizers, and coagulants) on the strength of alkaline-induced egg white gel were investigated. Results showed that NaOH concentration and induced temperature significantly affected the rate of formation and peak strength of the egg white gel. Of the 6 metallic compounds used in this experiment, CuSO4exhibited the optimal effect on the strength of alkaline-induced egg white gel, followed by MgCl2, ZnSO4, PbO, and CaCl2. When CuSO4concentration was 0.2%, the gel strength increased by 31.92%. The effect of Fe2(SO4)3was negligible. Of the 5 carbohydrate additives, xanthan gum (0.2%) caused the highest increase (54.31%) in the strength of alkaline-induced egg white gel, followed by sodium alginate, glucose, starch, and sucrose. Meanwhile, propylene glycol (0.25%) caused the highest improvement (15.78%) in the strength of alkaline-induced egg white gel among the 3 stabilizing agents and coagulants used, followed by Na2HPO4and glucono-δ-lactone.

Dichloridotetra-kis-(diniconazole)nickel(II).

In the title compound, [NiCl(2)(C(15)H(17)Cl(2)N(3)O)(4)], the Ni atom lies on an inversion center and has an axially extended trans-NiCl(2)N(4) octa-hedral geometry arising from its coordination by four diniconazole [systematic name: (E)-(RS)-1-(2,4-dichloro-phen-yl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol] ligands and two chloride ions. In the crystal, O-H⋯Cl hydrogen bonds link the mol-ecules into [100] chains.

Dichloridotetra-kis-(diniconazole)cobalt(II).

In the crystal structure of the title compound, [CoCl(2)(C(15)H(17)Cl(2)N(3)O)(4)], the Co(II) cation lies on an inversion center and has a slightly distorted octa-hedral coordination geometry. The equatorial positions are occupied by four N atoms from four diniconazole [systematic name: (E)-(RS)-1-(2,4-dichloro-phen-yl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol] ligands. The axial sites are occupied by two Cl(-) anions. In the two independent organic ligands, the triazole ring is oriented at dihedral angles of 18.28 (14) and 32.15 (14)° with respect to the dichloro-phenyl ring. Inter-molecular O-H⋯Cl hydrogen bonds consolidate the crystal packing.

[(E)-(1-Phenyl-ethyl-idene)amino]-urea methanol monosolvate.

In the title compound, C(9)H(11)N(3)O·CH(4)O, the semicarbazone moiety is nearly planar [maximum deviation = 0.017 (2) Å] and is twisted by a dihedral angle of 29.40 (13)° with respect to the phenyl ring. The semicarbazone moiety and phenyl ring are located on opposite sides of the C=N bond, showing the E configuration. An inter-molecular O-H⋯O and N-H⋯O hydrogen-bonding network occurs in the crystal structure.

Diniconazole.

THE ASYMMETRIC UNIT OF THE TITLE COMPOUND [SYSTEMATIC NAME: (E)-1-(2,4-dichloro-phen-yl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol], C(15)H(17)Cl(2)N(3)O, contains two mol-ecules in which the dihedral angles between the triazole and benzene rings are 9.4 (2) and 35.0 (2)°. In the crystal, the mol-ecules are linked by O-H⋯N hydrogen bonds, forming C(7) chains propagating in [010].