Environmental-friendly, flexible silk fibroin-based film as dual-responsive shape memory material.

Bio-based shape memory materials have attracted wide attention due to their biocompatibility, degradability and safety. However, designing and manufacturing wearable bio-based shape memory films with excellent flexibility and toughness is still a challenge. In this work, silk fibroin substrate with a ß-sheet structure was combined with a tri-block shape memory copolymer to prepare a transparent composited shape memory film. The silk fibroin-based film showed a dual-responsive shape memory function, which can respond to both temperature and water stimuli. This film has a sensitive water-responsive shape memory, which starts deforming after exposure to water for 3 s and fully recovers in 30 s. In addition, the composite film shows highly stretchable (>300 %) and could maintain its high tensile properties after 5 cycles of regeneration. The films also exhibited rapid degradation ability. This study provides new insights for the design of dual-responsive shape memory materials by combining biocompatible matrix and multi-block SMP to simultaneously enhance the mechanical properties, which can be used for intelligent packaging, medical supplies, soft actuators and wearable devices.

Sustainable production of bacterial flocculants by nylon-6,6 microplastics hydrolysate utilizing Brucella intermedia ZL-06.

Nylon-6,6 microplastics (NMPs) in aquatic systems have emerged as potential contaminants to the global environment and have garnered immense consideration over the years. Unfortunately, there is currently no efficient method available to eliminate NMPs from sewage. This study aims to address this issue by isolating Brucella intermedia ZL-06, a bacterium capable of producing a bacterial polysaccharide-based flocculant (PBF). The PBF generated from this bacterium shows promising efficacy in effectively flocculating NMPs. Subsequently, the precipitated flocs (NMPs + PBF) were utilized as sustainable feedstock for synthesizing PBF. The study yielded 6.91 g/L PBF under optimum conditions. Genome sequencing analysis was conducted to study the mechanisms of PBF synthesis and nylon-6,6 degradation. The PBF exhibited impressive flocculating capacity of 90.1 mg/g of PBF when applied to 0.01 mm NMPs, aided by the presence of Ca2+. FTIR and XPS analysis showed the presence of hydroxyl, carboxyl, and amine groups in PBF. The flocculation performance of PBF conformed to Langmuir isotherm and pseudo-first-order adsorption kinetics model. These findings present a promising approach for reducing the production costs of PBF by utilizing NMPs as sustainable nutrient sources.

Synthesis, X-Ray Crystal Structure of Oxidovanadium(V) Complex Derived from 4-Bromo-N’-(2-hydroxybenzylidene) benzohydrazide with Catalytic Epoxidation Property.

A new oxidovanadium(V) complex, [VOL(OCH3)(CH3OH)], where H2L = 4-bromo-N'-(2-hydroxybenzylidene)benzohydrazide, has been synthesized and fully characterized on the basis of CHN elemental analysis, FT-IR, UV-Vis, 1H and 13C NMR spectroscopy. Structures of the free hydrazone and the complex were further characterized by single crystal X-ray diffraction, which indicates that the V atom in the complex adopts octahedral coordination, and the hydrazone ligand behaves as a tridentate ligand. The catalytic epoxidation property of the complex was investigated.

N’-(2-Hydroxybenzylidene)-3-Methylbenzohydrazide and its Copper(II) Complex: Syntheses, Characterization, Crystal Structures and Biological Activity.

The hydrazone compound N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide (H2L) was prepared. With H2L and copper acetate a new copper complex [Cu(HL)(NCS)]·CH3OH was synthesized. Both the hydrazone and the copper complex were characterized by physico-chemical methods and single crystal X-ray diffraction techniques. The complex is a thiocyanato-coordinated copper(II) species. The Cu atom in the complex is in square planar geometry. The complex is a promising urease inhibitor.

Syntheses, Crystal Structures and Catalytic Property of Oxidovanadium(V) Complexes Derived from Tridentate Hydrazone Ligands.

Two new ethyl maltolato coordinated mononuclear oxidovanadium(V) complexes [VOLa(emt)]·DMF (1) and [VOLb(emt)] (2), where H2La = N'-(4-bromo-2-hydroxybenzylidene)-3-hydroxybenzohydrazide, H2Lb = N'-(4-bromo-2-hydroxybenzylidene)benzohydrazide, Hemt = ethyl maltol, have been synthesized and characterized on the basis of CHN elemental analysis, FT-IR and UV-Vis spectroscopy and powder XRD analysis. Structures of the complexes were further characterized by single crystal X-ray diffraction, which indicated that the V atoms in the complexes adopt octahedral coordination. The hydrazones behave as NOO tridentate ligands. The catalytic epoxidation properties on cyclooctene of the complexes were investigated.

Synthesis, Characterization and X-Ray Crystal Structures of cis-Dioxomolybdenum(VI) Complexes of Similar Tridentate Aroylhydrazone Schiff Bases with Catalytic Epoxidation Activity.

Two new cis-dioxomolybdenum(VI) complexes with general formula [MoO2L(MeOH)], where L = L1 = N'-(3,5-dibromo-2-hydroxybenzylidene)-4-trifluoromethylbenzohydrazide for complex 1, and L = L2 = N'-(3-bromo-5-chloro-2-hydroxybenzylidene)-4-trifluoromethylbenzohydrazide for complex 2, have been synthesized and fully characterized on the basis of elemental analysis, FT-IR, molar conductivity, and electronic spectra. The complexes are also characterized by single crystal X-ray diffraction. The complexes have distorted octahedral structures in which the aroylhydrazones behave as dianionic ligands. It is also revealed from the crystal structures that the Mo(VI) center adopts NO5 donor environment, and the octahedral coordination is furnished by two oxido groups and oxygen atoms of neutral methanol molecules. The catalytic properties were investigated for epoxidation of cyclooctene using aqueous tert-butyl hydroperoxide as the oxidant.

Synthesis, structure and urease inhibition studies of Schiff base copper(II) complexes with planar four-coordinate copper(II) centers.

Seven new Schiff base copper(II) complexes with planar four-coordinate copper(II) centers have been synthesized and structurally characterized. The solid state structures of complexes 1, 3, 4, 5, 6 and 7 present a square-planar coordination geometry at the metal centers while complex 2 shows a slightly distorted square-planar geometry. Density functional theory calculations have been performed to evaluate the electronic structure of copper(II) complex 7. Inhibition of jack bean urease by copper(II) complexes 1-7 have also been investigated, and potent inhibitory activities with IC50 range of 2.60-17.00µM have been observed for these mononuclear copper(II) complexes. A docking analysis using a DOCK program was conducted to explain the urease inhibitory activity of the copper(II) complexes and the structure-activity relationships were further discussed.

Synthesis, structures and urease inhibition studies of Schiff base metal complexes derived from 3,5-dibromosalicylaldehyde.

Eleven mononuclear copper(II), nickel(II), zinc(II) and cobalt(II) complexes of Schiff base ligands derived from 3,5-dibromosalicylaldehyde/3,5-dichlorosalicylaldehyde were synthesized and determined by single crystal X-ray analysis. The crystal structures of complexes 1, 2, 4, 5, 6, 8 and 11 present the square-planar coordination geometry at the metal center and complexes 7, 9 and 10 show the distorted tetrahedral geometry. While one copper center in 3 has a square-planar geometry, the other copper is slightly distorted square-planar. The inhibitory activities of all the obtained complexes were tested in vitro against jack bean urease. It was found that Schiff base copper(II) complexes 1, 3, 5, 8 and 11 showed strong urease inhibitory activities (IC(50) = 1.51-3.52 µM) compared with acetohydroxamic acid (IC(50) = 62.52 µM), which was a positive reference. Their structure-activity relationships were further discussed.

Synthesis, inhibitory activity and molecular docking studies of two Cu(II) complexes against Helicobacter pylori urease.

Two mononuclear copper(II) complexes, [Cu(C(15)H(16)NO(2))(2)] (1) and [Cu(C(6)H(9)N(2)O(4))(2)·3H(2)O] (2·3H(2)O), were synthesised and structurally characterised by single-crystal X-ray analysis. The copper(II) atom adopts a square-planar environment in complex 1, while the geometry in 2·3H(2)O could be described as the distorted square pyramidal. Complexes 1 and 2·3H(2)O were evaluated for their inhibitory activities against Helicobacter pylori (H. pylori) urease in vitro. They both were found to have strong inhibitory activities against H. pylori urease comparable to that of acetohydroxamic acid (AHA). A docking simulation was performed to position 2 into the H. pylori urease active site to determine the probable binding conformation.

Synthesis, structures and urease inhibition studies of copper(II) and nickel(II) complexes with bidentate N,O-donor Schiff base ligands.

Five mononuclear copper(II) and nickel(II) complexes of Schiff base ligands derived from 4-hydroxyphenethylamine and 2-phenylethylamine were synthesized and determined by single crystal X-ray analysis. The crystal structures of these complexes presented the square planar coordination geometry at the metal center. The inhibitory activity of all the obtained complexes was tested in vitro against jack bean urease. It was found that Schiff base copper(II) complexes, namely [Cu(C(15)H(13)BrNO(2))(2)]·2(C(6)H(7)N) (1), [Cu(C(15)H(12)Br(2)NO(2))(2)]·2(DMF) (2), Cu(C(19)H(16)NO(2))(2) (3) and Cu(C(19)H(16)NO)(2) (5), showed strong inhibitory activity against jack bean urease (IC(50)=1.45-3.59 µM), while Schiff base nickel(II) complex, [Ni(C(19)H(16)NO(2))(2)]·2(DMF) (4), exhibited weak inhibitory activity (IC(50)>50 µM). Their structure-activity relationships were further discussed.

Synthesis, molecular docking and biological evaluation of Schiff base transition metal complexes as potential urease inhibitors.

Six transition metal compounds of Schiff base ligands were evaluated for the inhibitory activity on jack bean urease, of which compounds 2-6 were determined by single crystal X-ray analysis. It was found that copper(II) complexes 1 and 4 showed strong inhibitory activity against jack bean urease (IC(50) = 0.52 and 0.46 microM), compared with acetohydroxamic acid (IC(50) = 42.12 microM) as a positive reference. Cobalt(II), nickel(II) and zinc(II) compounds also exhibited potent inhibitory activity (IC(50) = 3.88-25.20 microM). A docking analysis using the AUTODOCK 4.0 program could explain the inhibitory activities of 1 and 4 against urease.

Factors influencing glabridin stability.

Glabridin, a polyphenolic isoflavan of Glycyrrhiza glabra, has shown a variety of pharmaceutical properties. We have previously studied the isolation of glabridin using macroporous resin and found that it is partially degraded, giving a dark color. To illustrate the degradation of glabridin, the present work studied the stability of glabridin under various conditions. Licorice extract containing about 20% glabridin, obtained from G. glabra by silica gel column chromatography, was used in the stability study. Seven different factors (temperature, illumination, humidity, pH, solvent, oxygen, and oxidant) were studied and content changes were determined through HPLC analysis. Except for oxygen, all the above factors had an effect on the stability of glabridin, with illumination being the main one. Moreover, the interactions between temperature and pH, temperature and humidity, and illumination and pH can promote the degradation of glabridin. In conclusion, we suggest that a dark, dry and airtight environment provides the optimized condition for the long-term storage of glabridin.

Aqua-bis(5-methyl-pyrazine-2-carboxyl-ato)zinc(II) trihydrate.

In the title compound, [Zn(C(6)H(5)N(2)O(2))(2)(H(2)O)]·3H(2)O, the Zn(II) centre is five-coordinated by two O,N-bidentate Schiff base ligands and one O atom from a water mol-ecule in a slightly distorted square-pyramidal geometry. In the crystal, the complex and uncoordinated water mol-ecules are linked by O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds, forming a three-dimensional network.

Bis{2-[(1H-pyrrol-2-yl)methyl-imino-meth-yl]phenolato-κN,O}zinc(II).

In the title compound, [Zn(C(12)H(11)N(2)O)(2)], the Zn(II) atom, lying on an inversion center, is coordinated by two O atoms and two N atoms from two salicylal Schiff base ligands in a distorted square-planar geometry. A three-dimensional network is formed by inter-molecular C-H⋯N hydrogen bonds and C-H⋯π contacts.

2,4-Disulfanyl-6-[(E)-(2-sulfanylbenz-yl)imino-meth-yl]phenol.

In the title compound, C(14)H(13)NOS(3), the dihedral angle between the benzene rings is 73.26 (5)° and an intra-molecular O-H⋯N hydrogen bond occurs.

Diaqua-bis[2-(4-bromo-phen-yl)acetato]bis-(N,N-dimethyl-pyridin-4-amine)copper(II).

In the title compound, [Cu(C(8)H(6)BrO(2))(2)(C(7)H(10)N(2))(2)(H(2)O)(2)], the Cu(II) atom (site symmetry ) adopts a Jahn-Teller-distorted trans-CuN(2)O(4) octa-hedral coordination, with the aqua O atoms in axially extended sites. An intra-molecular O-H⋯O hydrogen bond helps to establish the conformation and an inter-molecular O-H⋯O hydrogen bond is seen in the crystal packing.

Bis(2-cyclo-hexyl-imino-methyl-4,6-dihydro-seleno-phenolato)cobalt(II) acetonitrile solvate.

In the title compound, [Co(C(13)H(16)NOSe(2))(2)]·CH(3)CN, the Co(II) atom is four-coordinated by two N,O-bidentate Schiff base ligands, resulting in a distorted tetra-hedral coordination for the metal ion.

Anti-inflammatory activity of licochalcone A isolated from Glycyrrhiza inflata.

Licochalcone A was isolated from the roots of Glycyrrhiza inflata and evaluated for its anti-inflammatory activity in xylene-induced mice ear edema and carrageenan-induced paw edema tests. At the same time, the inhibition of prostaglandin biosynthesis by licochalcone A was also studied in lipopolysaccharide (LPS)-induced mouse macrophage cells. At 5 mg/ ear, licochalcone A showed remarkable effects against acute inflammation induced by xylene, and at the doses of 2.5, 5, 10 mg/kg (p.o.), licochalcone A reduced significantly paw edema induced by carrageenan compared to the control at the fourth hour. Both COX-2 activity and expression were significantly inhibited by licochalcone A at all the test doses. Therefore, licochalcone A could be a useful compound for the development of new anti-inflammatory agents.

Effect of glabridin from Glycyrrhiza glabra on learning and memory in mice.

Glabridin was isolated from the roots of Glycyrrhiza glabra and its effects on cognitive functions and cholinesterase activity were investigated in mice. Glabridin (1, 2 and 4 mg kg (-1), P. O.) and piracetam (400 mg kg (-1), i. p.), a clinically used nootropic agent, were administered daily for 3 successive days to different groups of mice. The higher doses (2 and 4 mg kg (-1), P. O.) of glabridin and piracetam significantly antagonized the amnesia induced by scopolamine (0.5 mg kg (-1), I. P.) in both the elevated plus maze test and passive avoidance test. Furthermore, glabridin (2 and 4 mg kg (-1), P. O.) and metrifonate (50 mg kg (-1), I. P.), used as a standard drug, both remarkably reduced the brain cholinesterase activity in mice compared to the control group. Therefore, glabridin appears to be a promising candidate for memory improvement and it will be worthwhile to explore the potential of glabridin in the management of Alzheimer patients.

Ethyl 3-(2,4-difluoro-phen-oxy)-2-(4-methoxy-phen-yl)acrylate.

In the title mol-ecule, C(18)H(16)F(2)O(4), the two benzene rings form a dihedral angle of 55.2 (2)°. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into chains propagating along the c axis.