A Cadmium Coordination Polymer Based on Phosphate Clusters: Synthesis,Crystal Structure,Electrochemical Investigation and Antibacterial Activity

A new d¹⁰ coordination polymer, \(\left\{ {\left( {{\text{C}}_{5} {\text{H}}_{14} {\text{N}}_{2} } \right)_{2} \left[ {{\text{Cd}}\left( {\left( {{\text{P}}_{6} {\text{O}}_{18} } \right)\left( {{\text{H}}_{2} {\text{O}}} \right)_{2} } \right)} \right] \cdot 6{\text{H}}_{2} {\text{O}}} \right\}_{n}\), was prepared and characterized by X-ray diffraction, IR-Raman spectroscopy, thermal analysis and cyclic voltammetry. The crystal structure determination reveals that the phosphate anions alternate with the cadmium octahedral to form an anionic coordination polymer extending along [001] direction. The double protonated homopiperazine cations and the water molecules ensure the interconnection between polymers and thus giving rise to three dimensional supramolecular networks. By means of cyclic voltammetry, it is shown that whilst the reduction of the complexed Cd²⁺ occurs with a biggest difficulty than this of its free form, the anodic oxidation of the heterocyclic N donor piperazine became quite easy, when it is displayed as a counterpart diprotonated cation, between the anionic layers of \(\left[ {{\text{Cd}}({\text{P}}_{6} {\text{O}}_{18} )({\text{H}}_{2} {\text{O}})_{2} )} \right]_{\text{n}}^{{4{\text{n}} - }}\). The antibacterial activity of the coordination polymer is also discussed.     

Modulation of antioxidant systems by subchronic exposure to the aqueous extract of leaves from Achillea millefolium L. in rats

We determined the effects of subchronic exposure to aqueous extract of leaves from Achillea millefolium (AE) on enzyme- and non-enzyme-dependent antioxidant systems in rats. Seven days treatment with AE (1 g/kg/twice a day, p.o.) altered the reduced glutathione (GSH) levels and antioxidant enzyme activities in several organs of the animals. Amount of GSH in uterus was increased (73%) while in kidneys it was decreased (23%). Besides, NAD(P)H quinone oxidoreductase 1 (NQO1) activity was increased in forestomach (26%) and in liver (64%), while glutathione S-transferase activity was decreased in the forestomach (32%) and increased in the liver (41%), kidney (35%) and uterus (37%). In preliminary experiments targeting the interaction of AE with acetaminophen (600 mg/kg, p.o.), we observed augmentation of acetaminophen-induced increase of the plasmatic alanine aminotransaminase, aspartate aminotransaminase and lactate dehydrogenase. Overall, the results indicate a potential toxic interaction of AE compounds with xenobiotics that use the glutathione pathway.     

Inside Back Cover: Surfactant Directed Synthesis of Intrinsically Chiral Plasmonic Nanostructures and Precise Tuning of their Optical Activity through Controlled Self-Assembly (Angew. Chem. Int. Ed. 21/2023)

Fabrication and transmission of plasmonic chirality is a rapidly developing area of research. While nanoscale chirality is reasonably well explored, research on intrinsically chiral nanostructures, that has ramifications to origin of homochirality, is still in its infancy. Herein, we report the synthesis of dog-bone shaped chiral gold nanostructures using a chiral cationic surfactant with excess ascorbic acid. Chiral growth is attributed to the specific binding and structure breaking ability of chiral surfactant and ascorbic acid. The controlled assembly of particles facilitated tuning and enhancement of chiral signals. Experimental observations were validated with theoretical simulations modelled in frequency domain with a surface integral-equation parameterization. Work highlighting the generation and tuning of plasmonic chirality provides new insights into the understanding of intrinsic chirality and paves way for their application in enantioselective catalysis and biosensing.     

Simultaneous determination of chlorzoxazone and ketoprofen in binary mixtures and in ternary mixtures containing the chlorzoxazone degradation product by reversed-phase liquid chromatography

New, simple, rapid, and precise reversed-phase high-performance liquid chromatographic (LC) methods were developed for the simultaneous determination of chlorzoxazone (CH) and ketoprofen (KT) in binary mixtures and in ternary mixtures containing the CH degradation product, 2-amino-4-chlorophenol (CD). The analytes were separated by LC on a Lichrosphere 60 C18 column (250 x 4 mm, 5 microm). The mobile phases, methanol-water (40:60, v/v) at 1 mL/min and methanol-0.05% phosphoric acid (60:40, v/v, pH 2.81) at 1.5 mL/min, satisfactorily resolved the binary and ternary mixtures, respectively. The UV detector was operated at 280 nm for the determination of CH and at 254 nm for the determination of KT and CD. Linearity, accuracy, and precision were found to be acceptable over the concentration ranges of 20-240 and 5-60 microg/mL for CH and KT, respectively, in the binary mixtures and 50-300, 10-60, and 20-160 microg/mL for CH, KT, and CD, respectively, in the ternary mixtures. The optimized methods proved to be specific, robust, and accurate for the quality control of CH and KT in pharmaceutical preparations.     

Deacetylcephalosporin C production in Penicillium chrysogenum by expression of the isopenicillin N epimerization, ring expansion, and acetylation genes

Penicillium chrysogenum npe6 lacking isopenicillin N acyltransferase activity is an excellent host for production of different beta-lactam antibiotics. We have constructed P. chrysogenum strains expressing cefD1, cefD2, cefEF, and cefG genes cloned from Acremonium chrysogenum. Northern analysis revealed that the four genes were expressed in P. chrysogenum. The recombinant strains TA64, TA71, and TA98 secreted significant amounts of deacetylcephalosporin C, but cephalosporin C was not detected in the culture broths. DAC-acetyltransferase activity was found in all transformants containing the cefG gene. HPLC analysis of cell extracts showed that transformant TA64, TA71, and TA98 accumulate intracellularly deacetylcephalosporin C and, in the last strain (TA98), also cephalosporin C. Mass spectra analysis confirmed that transformant TA98 synthesize true deacetylcephalosporin C and cephalosporin C. Even when accumulated intracellularly, cephalosporin C was not found in the culture broth.     

Zinc in gastrointestinal and liver disease

Zinc is an essential trace element with important biological functions, depending on the structural and/or catalytic role played by zinc ions in a large variety of enzymes. Zinc plays a critical role in cellular integrity, protein synthesis, nucleic acid metabolism, contributing to cell growth, proliferation, differentiation and death. The present review reports data on zinc homeostasis and metabolism, zinc absorption, intercellular trafficking, intracellular transport inside enterocytes and hepatocytes. Particular emphasis is given to data regarding the role of zinc carriers ZnTs and Zips, and to their expression in liver and gut in experimental and in human studies. The role of zinc in the gastrointestinal tract and in the liver as a powerful antioxidant and its relationship with apoptosis is discussed. Possible implications of zinc status in different disorders of the gastrointestinal tract are presented, focusing on its possible introduction in the therapy of inflammatory bowel diseases. Data on the role of zinc and zinc carriers in the evolution of liver fibrosis towards cirrhosis are also discussed. Finally, data on the ability of zinc therapy to obtain regression of liver cirrhosis in patients affected by Wilson's disease are reported, and the hypothesis that zinc could protect against liver fibrosis in chronic liver disease of different origin is presented.     

Hartree-Fock and Kohn-Sham time-dependent response theory in a second-quantization atomic-orbital formalism suitable for linear scaling

We present a second-quantization based atomic-orbital method for the computation of time-dependent response functions within Hartree-Fock and Kohn-Sham density-functional theories. The method is suited for linear scaling. Illustrative results are presented for excitation energies, one- and two-photon transition moments, polarizabilities, and hyperpolarizabilities for hexagonal BN sheets with up to 180 atoms.