Synthesis,spectral, DFT calculations and biological studies of solvatochromic copper(II)-ONS hydrazone derived from 2-aminochromone-3-carboxaldehyde

New ONS hydrazone ligand, 2-[(2-aminochromon-3-yl)methylidene]-N-phenylhydrazinecarbothioamide, HL , was synthesized and reacted with different salts of Cu (II) ion (OAc⁻, NO₃⁻, SO₄²⁻ and Cl⁻) in absence and presence of secondary ligands (L′); 8-hydroxyquinoline, 1,10-phenanthroline or SCN⁻; to form binary and ternary Cu(II)-chelates. The ligand and its Cu(II)-complexes were fully characterized by analytical, spectral, thermal, conductivity and magnetic susceptibility measurements. The metal chelates showed octahedral, square planar and /or distorted tetraherdal arrangements. Coats–Redfern equations used to calculate the kinetic parameters of the thermal decomposition stages (E_a, A, ΔH, ΔS and ΔG). The compounds exhibit luminescence property; promising interesting potential applications as photoactive materials. Lippert–Mataga, Bakhshiev, Kawski–Chamma–Viallet and microscopic solvent polarity parameter and E_T^N correlation methods were applied on the solvatochromic shifts of emission spectra to evaluate the ground (μ_g) and excited (μ_e) states dipole moments. Excited state dipole moment is larger than the ground state which may be attributed to π-π* transition. The coordinating anions play an important role on the position and intensity of emission band. The ligand and its metal complexes showed antimicrobial activity towards Gram–positive bacteria, Gram–negative bacteria, yeast and fungus. The molecular structural parameters of HL and its Cu(II)- complexes have been calculated on the basis of DFT engaged in the Gaussian 09 program at the B3LYP/6-31G(d,p) level; the theoretical data are correlated with the experimental data.     

A Highly Stable (4, 8)-Connected Tb-MOF Exhibiting Efficiently Luminescent Sensing towards Nitroimidazole Antibiotics

A robust 4,8-connected Tb-based metal-organic framework (Tb-MOF) with paddle wheel-shaped {Tb₂(COO)₄} subunits extended by C₃-symmetric 3,3',3''-[1,3,5-benzenetriyltris(carbonylimino)]tris-benzoate connector was hydrothermally synthesized, showing highly environmental stability, good dispersion and intense green emission in water system. Resulting critically from the well suppressed absorption towards the excitation energy, the Tb-MOF exhibits rapid and efficient fluorescent response towards nitroimidazole antibiotics with strong quenching constants and low detection limits of 1.59 × 10⁴ m ^–1 and 2.4 μM for metronidazole as well as 1.62 × 10⁴ m ^–1 and 2.9 μM for dimetridazole. Moreover, the sensitive and selective identification of the Tb-MOF has strong anti-interference and excellent regeneration ability, which endows the promising applications of the Tb-MOF as fluorescent sensing materials.     

New monodentate and bidentate silylene ligands by DFT

Considering the importance of silylene ligands in transition metal-mediated catalytic reactions, we have scrutinized eight novel monodentate ( 1 – 4 ) and bidentate ( 1 ^′ - 4 ^′ ) derivatives of 2,5-diX-cyclopentasilylene-2,4-dienes (X = NH₂, OH, PH₂, and SH), at M06/6-311++G** level of theory. To probe the complexation ability of our scrutinized silylene ligands with Rh atom ( 1 _Rh - 4 _Rh and 1 ^′ _Rh - 4 ^′ _Rh , respectively), thermodynamic and structural parameters such as complexation energy (ΔE_Com), singlet-triplet energy gap (ΔE_s-t), bond length, along with NBO and atoms in molecules analyses are provided. In going from less electron donating groups (EDGs) to more EDGs (NH₂ > OH > PH₂ > SH), the σ -donor strength and ligand flexibility increase. Structures 1 and 1 ^′ turn out as the most nucleophilic species for showing the highest nucleophilicity (N = 5.47 and 5.40 eV, respectively). Furthermore, they exhibit the highest proton affinity values (PA = 271.46 and 271.23 kcal/mol, respectively). The results indicate that bidentate coordination mode of silylene leads to a stronger Si-Rh complex. The overall orders of σ -donation ability for monodentate and bidentate silylene ligands are 1 > 2 > 3 > 4 and 1 ^′ > 2 ^′ > 3 ^′ > 4 ^′ , respectively.     

Composite host lattices of 4,4′‐sulfonyldibenzoate water/boric acid in two tetrapropylammonium inclusion compounds

Two novel inclusion compounds of 4,4′‐sulfonyldibenzoate anions and tetrapropylammonium cations with different ancillary molecules of water and boric acid, namely bis(tetrapropylammonium) 4,4′‐sulfonyldibenzoate dihydrate, 2C₁₂H₂₈N⁺·C₁₄H₈O₆S²⁻·H₂O ( 1 ), and bis(tetrapropylammonium) 4,4′‐sulfonyldibenzoate bis(boric acid), 2C₁₂H₂₈N⁺·C₁₄H₈O₆S²⁻·2H₃BO₃ ( 2 ), were prepared and characterized using single‐crystal X‐ray diffraction. In the two salts, the host 4,4′‐sulfonyldibenzoic acid molecules, which are converted to the corresponding anions under basic conditions, can be regarded as proton acceptors which link different proton donors of the ancillary molecules of water or boric acid. In this way, an isolated hydrogen‐bonded tetramer is constructed in salt 1 and a ribbon is constructed in salt 2 . The tetramers and ribbons are then packed in a repeating manner to generate various host frameworks, and the tetrapropylammonium guest counter‐ions are contained in the cavities of the host lattices to give the final stable crystal structures. In these two salts, although the host anion and guest cation are the same, the difference in the ancillary small molecules results in different structures, indicating the significance of ancillary molecules in the formation of crystal structures.     

Determination,residue and risk assessment of trifloxystrobin,trifloxystrobin acid and tebuconazole in Chinese rice consumption

A simple and rapid analytical method for the detection of trifloxystrobin, trifloxystrobin acid and tebuconazole in soil, brown rice, paddy plants and rice hulls was established and validated by liquid chromatography with tandem mass spectrometry. Acceptable linearity (R² > 0.99), accuracy (average recoveries of 74.3–108.5%) and precision (intra- and inter-day relative standard deviations of 0.9–8.8%) were obtained using the developed determination approach. In the field trial, the half-lives of trifloxystrobin and tebuconazole in paddy plants were 5.7–8.3 days in three locations throughout China, and the terminal residue concentrations of trifloxystrobin and tebuconazole were <100 and 500 μg/kg (maximum residue limits set by China), respectively, at harvest, which indicated that, based on the recommended application procedure, trifloxystrobin and tebuconazole are safe for use on rice. The risk assessment results demonstrated that, owing to risk quotient values of both fungicides being <100%, the potential risk of trifloxystrobin and tebuconazole on rice was acceptable for Chinese consumers. These data could provide supporting information for the proper use and safety evaluation of trifloxystrobin and tebuconazole in rice.     

Curing behavior and properties of high biosourced epoxy resin blends based on a triepoxy monomer and a tricarboxylic acid hardener from 10-undecenoic acid

Renewable propane-1,2,3-triyl tris(9-(oxiran-2-yl) nonanoate) (EGU, 100 wt% biogenic) and a tricarboxylic acid triglyceride (CGTU) hardener (85.7 wt% biogenic) were synthesized from 10-undecenoic acid (10-UDA) and used to produce epoxy resins with 52–92 wt% biobased carbon. CGTU was prepared by thermally activated thiol-ene coupling of thioglycolic acid onto propane-1,2,3-triyl tris(undec-10-enoate), (GUD) in the absence of solvent. The characterized CGTU was used as a green hardener of blends based on EGU and a conventional bisphenol A-based epoxy pre-polymer (DGEBA) at various mass percentages (0–100 wt%) with an stoichiometric epoxy/acid equivalent ratio. Calorimetric studies revealed higher peak temperature, lower reaction heats, and longer gelation times in resins with high EGU proportion, evidencing the lower reactivity of aliphatic EGU compared with aromatic DGEBA. Cured resins were yellowish transparent rubber-like materials with glass transition temperatures (Tg) varying from −14 °C to −42 °C and tensile strength in the range of 1750 kPa–790 kPa, for 0 and 100 wt % EGU, respectively. The soluble fraction of all resins was less than 4.3%, reflecting a high level of crosslinking. Thermosets with high biobased content showed both UV-light protection and visible light transparency.     

The effect of triethyl citrate on the dispersibility and water vapor sorption behavior of polylactic acid/zeolite composites

The aim of this study was to investigate the water vapor adsorption behavior and mechanical properties of poly (lactic acid) (PLA)/zeolite (5, 10, or 15 phr) composites prepared with triethyl citrate (TEC; 20 phr) via a melting process. TEC was used to improve the flexibility of the PLA and the dispersibility of the zeolite in TEC-zeolite suspensions that were ultra-sonicated. It was found that zeolite was uniformly dispersed in the PLA matrix, and the interfacial adhesion between the PLA matrix and zeolite was enhanced by TEC. In addition, the tensile strengths and Young's modulus of the composites improved with increasing zeolite content. The PLA/zeolite composites prepared with TEC had increased water vapor permeability and contact angles compared to neat PLA and standard PLA/zeolite due to the presence of TEC. In particular, TEC accelerated the hydrolysis of the PLA surface in a high humidity environment, resulting in an improvement in water vapor sorption capacity. At the same zeolite content of 15 phr, the equilibrium moisture content (EMC) values of PLA/zeolite films prepared with TEC increased by up to 39.25 mg/g whereas those prepared without TEC only increased by up to 24.33 mg/g. The results suggest the possibility of applying PLA/zeolite films prepared with TEC as a flexible active packaging material.     

Production and characterization of elastomeric cardiac tissue-like patches for Myocardial Tissue Engineering

Cardiovascular disease remains the leading cause of death. Damaged heart muscle is the etiology of heart failure. Heart failure is the most frequent cause of hospital and emergency room admissions. As a differentiated organ, current therapeutics and techniques can not repair or replace the damaged myocardial tissue. Myocardial tissue engineering is one of the promising treatment modalities for repairing damaged heart tissue in patients with heart failure. In this work, random Polylactic acid (PLA), Polylactic acid/Polyethylene glycol (PLA/PEG) and random and aligned Polylactic acid/Polyethylene glycol/Collagen (PLA/PEG/COL) nanofiber patches were successfully produced by the electrospinning technique. In vitro cytotoxic test (MTT), morphological (SEM), molecular interactions between the components (FT-IR), thermal analysis (DSC), tensile strength and physical analysis were carried out after production. The resulting nanofiber patches exhibited beadless and smooth structures. When the fiber diameters were examined, it was observed that the collagen doped random nanofiber patches had the lowest fiber diameter value (755 nm). Mechanical characterization results showed that aligned nanofiber patches had maximum tensile strength (5.90 MPa) values compared to PLA, PLA/PEG, and PLA/PEG/COL (random). In vitro degradation test reported that aligned patch had the highest degradation ratio. The produced patches displayed good alignment with tissue on cardiomyocyte cell morphology studies. In conclusion, newly produced patches have noticeable potential as a tissue-like cardiac patch for regeneration efforts after myocardial infarction.     

Purification of hyaluronidase as an anticancer agent inhibiting CD44

Hyaluronidase (Hyal) can be employed to accomplish a diversity of complications related to hyaluronic acid (HA). Hyal contains some classes of catalysts that cleave HA. This enzyme is detected in several human tissues as well as in animal venoms, pathogenic organisms and cancers. Destructive cancer cells regularly increase the CD44 receptor existing in a cell membrane. This receptor acts as an exact receptor for HA, and HA is recognized to motivate the migration, spread, attack and metastasis of cancer cells. Nearly all of the methods used to purify Hyal are highly costly and not proper for industrial applications. This survey aims to review different methods of Hyal purification, which acts as an anticancer agent by degrading HA in tissues and thus inhibiting the CD44–HA interaction. Hyal can be successfully employed in the management of cancer, which is associated with HA–CD44. This review has described different methods for Hyal purification to prepare an origin to develop a novel purification technique for this highly appreciated protein. Using multiple columns is not applicable for the purification of Hyal and thus cannot be used at the industrial level. It is better to use affinity chromatography of anti-Hyal for Hyal with one-step purification.     

Role of anti-inflammatory interventions in high-fat-diet-induced obesity

Lipotoxicity is defined as deposition of excess fat associated with an inflammatory response. Metabolomic analysis of fatty acids (FAs) can be a marker of silent inflammation. ω3-Enriched diet, celecoxib, and safranal may have a protective anti-inflammatory role. In this work, total FAs extracted from red blood cells and arachidonic acid-to-eicosapentaenoic acid (AA-to-EPA) ratios were assessed using GC–MS assay in single-ion monitoring mode. The study was conducted on 64 male rats divided into eight groups: I, controls; II, rats received high-fat diet (HFD), III, rats received ω-6-enriched HFD; IV, rats received ω-3-enriched HFD; V, rats received celecoxib with HFD; VI, rats received safranal with HFD; VII and VIII, rats received celecoxib and safranal with ω-3 HFD, respectively. GC–MS Gas chromatography Mass spectrometry was performed for analysis of fatty acid methyl ester. Enzyme-linked immunosorbent assay was used to analyze serum interleukin-6 (IL-6) and transforming growth factor-beta 1 (TGF-β1) concentrations. A statistically significant decrease of AA-to-EPA ratio was observed in group VII when compared with the groups receiving HFDs. This group also showed the lowest serum IL-6 level and highest TGF-β1 level. In conclusion, ω3-enriched diet along with drugs (e.g. celecoxib) and herbal medications (e.g. safranal) may have an anti-inflammatory effect in lipotoxicity. GC–MS with single-ion monitoring is valid for the analysis of FAs.