Ligand engineering to achieve synergistic properties in a 2D bilayer supertetrahedral chalcogenide cluster-based assembled material.

Incorporating functional organic linkers into supertetrahedral chalcogenolate cluster-based materials is an effective synthetic strategy to expand structural diversity and generate tunable optical and photoelectric properties arising from synergistic effects. Herein, a mixed ligand engineering approach was adopted to design a supertetrahedral cluster-based assembled material [(Cd6Ag4(SPh)16(TPPA)(BPE)0.5)·2DMF]n (denoted as SCCAM-3) with a 2D bilayer architecture and broader visible-light absorption. Interestingly, SCCAM-3 demonstrates a long-lived afterglow at 83 K and efficient photocatalytic activity for degrading tetracycline in water.

BL02, a phage against carbapenem- and polymyxin-B resistant Klebsiella pneumoniae, isolated from sewage: A preclinical study.

The emergence of Carbapenem-resistant Klebsiella pneumoniae (CRKP) represents a threat to public health. Polymyxin-B is generally considered a last-resort antibiotic. In this study, we isolated a carbapenem- and polymyxin-B resistant K. pneumoniae phage BL02 for the first time in Southwestern China and evaluated its biological characteristics and whole-genome sequence. Polymyxin-B resistant K. pneumoniae, (CK02), was isolated from the blood of a male with severe septic shock, and phage BL02 was screened and purified from the hospital sewage. BL02 could lyse 40 out of 46 CRKP isolates (86.96%) and has high activity in the pH range of 6-10 and the temperature range of 4-55 °C. The latency period of BL02 was about 10 min and the lysis period was about 50 min. The genome results showed that BL02 was a linear dsDNA with a total length of 175,595 bp and a GC content of 41.83%. A total of 275 ORFs were predicted and no tRNA, rRNA, drug resistance genes, or virulence genes were found in the genome. Phylogenetic analysis showed that BL02 belongs to the family Straboviridae. Treatment of infected mice with two antibiotics (tigecycline or ceftazidime/avibactam) resulted in 7-day survival rates of 28.57% and 42.86%, respectively. In contrast, the survival rate of mice in the single-dose BL02-treated group was 71.43%. In summary, this preclinical study isolated a phage capable of lysing polymyxin-B resistant K. pneumoniae and validated its safety and efficacy in an in vivo model, which provides a reference for further research on controlling MDR pathogens.

Synthesis, Biological Evaluation, and Molecular Docking Studies of Hydrazones as Novel Xanthine Oxidase Inhibitors.

A series of hydrazones, 2-cyano-N'-(4-diethylamino-2-hydroxybenzylidene)acetohydrazide (1), N'-(5-bromo-2-hydroxy-3-methoxybenzylidene)-3-chlorobenzohydrazide monohydrate (2·H2O), N'-(2-hydroxy-3-methylbenzylidene)-4-nitrobenzohydrazide (3), and N'-(2-hydroxy-3-trifluoromethoxybenzylidene)-4-nitrobenzohydrazide (4), were prepared and structurally characterized by elemental analysis, IR and 1H NMR spectra, and single crystal X-ray determination. Xanthine oxidase inhibitory activities of the compounds were studied. Among the compounds, 2-cyano-N'-(4-diethylamino-2-hydroxybenzylidene)acetohydrazide shows the most effective activity. Docking simulation was performed to insert the compounds into the crystal structure of xanthine oxidase at the active site to investigate the probable binding modes.

Synthesis, Crystal Structures and Catalytic Property of Dioxidomolybdenum(VI) Complexes with Tridentate Hydrazones.

New dioxidomolybdenum(VI) complexes with the formula [MoO2L(MeOH)], derived from N'-(5-chloro-2-hydroxy-benzylidene)-2-methylbenzohydrazide (H2L1) and N'-(3,5-dichloro-2-hydroxybenzylidene)-2-methylbenzohydrazide (H2L2) were prepared. Crystal and molecular structures of the complexes were determined by single crystal X-ray dif-fraction method. Both complexes were further characterized by elemental analysis and FT-IR spectra. Single crystal X-ray structural studies indicate that the hydrazones L1 and L2 coordinate to the MoO2 cores through the enolate oxygen, phenolate oxygen and azomethine nitrogen. The Mo atoms in both complexes are in octahedral coordination. Catalytic properties for epoxidation of styrene by the complexes using PhIO and NaOCl as oxidant have been studied.

Syntheses, X-Ray Single Crystal Structures and Biological Activities of Cobalt(III) Complexes with Reduced Schiff Base Ligands.

A new mononuclear cobalt(III) complex, [Co(HL1)2]Cl (1), derived from the reduced Schiff base 2,2'-((ethane-1,2-diylbis(azanediyl))bis(methylene))diphenol (H2L1), and a new dinuclear cobalt(III) complex, [Co2(L2)2]∆2H2O (2), derived from the reduced Schiff base 6,6'-(2-hydroxypropane-1,3-diyl)bis(azanediyl)bis(methylene)bis(2-bromo-4-chlorophenol) (H2L2), were synthesized and characterized by infrared and electronic spectroscopy, and single crystal X-ray diffraction techniques. The ligands were synthesized first, and then bound to the Co(III) centre. Compound 1 contains a mononuclear [Co(HL1)2]+ cation and a chloride anion. The cationic moiety possesses crystallographic inversion center symmetry. Compound 2 contains a dinuclear [Co2(L2)2] molecule and two water hydrate molecules. The Co atoms in the complexes are in octahedral coordination. Both complexes showed potential antimicrobial activity.

Synthesis, Crystal Structures and Antimicrobial Activity of Oxidovanadium(V) Complexes with Hydrazone and Pyrone Ligands.

A pair of oxidovanadium(V) complexes, [VOLL1] (1) and [VOLL2] (2), where L is the dianionic form of the hydrazone ligand N'-(5-chloro-2-hydroxybenzylidene)pivalohydrazide (H2L), L1 and L2 are the deprotonated forms of 3-hydroxy-2-methyl-4H-pyran-4-one (HL1; maltol) and 2-ethyl-3-hydroxy-4H-pyran-4-one (HL2; ethyl maltol), respectively, have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, and single-crystal X-ray crystallographic determination. The V atoms in the complexes are in octahedral coordination, with the hydrazone ligand coordinated to the V atoms through the phenolate O, imino N and enolate O atoms, and with the pyrone ligands coordinated to the V atoms through two O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.