Synthesis,characterization, DNA binding/cleavage,and anticancer and antimicrobial activities: Nano-sized Co(II) and Cd(II) complexes and their use as a precursor for CoO and CdO nanoparticles

In the search of effective bioactive compounds, Co(II) ( C1 ) and Cd(II) ( C2 ) complexes of the type [M(FMAPIMP)(H₂O)Cl].nH₂O (where M = Co(II); n = 2, Cd(II); n = 3, and FMAPIMP = ligand[2-((E)-((2-(((E)-furan-2-ylmethylene)amino)phenyl)imino)methyl)phenol]) were synthesized and characterized using elemental analysis, UV–Vis., cyclic voltammetry, Fourier-transform infrared (FT-IR), nuclear magnetic resonance, and mass spectral studies. The thermal stability of nano-sized Co(II) and Cd(II) complexes was studied using thermogravimetric analysis (TGA). Cobalt and cadmium oxides were synthesized using cobalt and cadmium nanoparticle (NP) structure Schiff base complexes as the raw material after calcination for 5 h at 600 °C. According to the results, Co(II) and Cd(II) complexes with mole ratio 1:1 of metal: H-FMAPIMP which octahedral are the most probable geometry for it. On the contrary, synthesized C1 and C2 NPs were used as suitable precursors for the preparation of CoO and CdO NPs. The obtained NPs were characterized using FT-IR, UV–Vis., TGA, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy techniques. PXRD analysis revealed that the obtained oxides were crystalline and corresponded to CoO and CdO phases. Crystal size, shape, and morphology were determined using SEM and TEM. H-FMAPIMP and its two complexes ( C1 and C2 ) were tested against human ovarian cancer cell line (PA-1). The synthesized Co(II) and Cd(II) complexes exhibited enhanced activity against the tested bacterial (Staphylococcus aureus and Escherichia Coli) and fungal strains (Candida albicans and Aspergillus fumigatus) as compared to H-FMAPIMP. The results of the DNA-cleavage activity indicated that the ligand and its two complexes can cleave calf thymus-DNA at different degrees. Further, antituberculosis activity was performed using microplate alamarBlue assay. Among all these synthesized compounds, C1 exhibited good cleaving ability compared to the newly synthesized C2 . Finally, the geometry of H-FMAPIMP and its Co(II) and Cd(II) complexes was optimized using molecular modeling.     

An LC-MS/MS Method for Analysis of Vitamin D Metabolites and C3 Epimers in Mice Serum: Oral Supplementation Compared to UV Irradiation

Introduction: The most common forms of vitamin D in human and mouse serum are vitamin D3 and vitamin D2 and their metabolites. The aim of this study is to determine whether diet and sunlight directly affect the circulating concentrations of vitamin D metabolites in a mouse model. We investigated the serum concentrations of eight vitamin D metabolites—vitamin D (vitamin D3 + vitamin D2), 25OHD (25OHD3 + 25OHD2), 1α25(OH)₂D (1α25(OH)₂D2, and 1α25(OH)₂D3)—including their epimer, 3-epi-25OHD (3-epi-25OHD3 and 3-epi-25OHD2), and a bile acid precursor 7alpha-hydroxy-4-cholesten-3-one (7αC4), which is known to cause interference in liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Method: The LC-MS/MS method was validated according to FDA-US guidelines. The validated method was used for the analysis of mouse serum samples. Forty blood samples from mice were collected and divided into three groups. The first group, the DDD mice, were fed a vitamin D-deficient diet (25 IU VD3/kg of diet) and kept in the dark; the second group, the SDD mice, were maintained on a standard-vitamin D diet (1000 IU VD3) and kept in the dark; and the third group, SDL, were fed a standard-vitamin D diet (1000 IU VD3) but kept on a normal light/dark cycle. LC-MS/MS was used for the efficient separation and quantitation of all the analytes. Results: The validated method showed good linearity and specificity. The intraday and interday precision were both <16%, and the accuracy across the assay range was within 100 ± 15%. The recoveries ranged between 75 and 95%. The stability results showed that vitamin D metabolites are not very stable when exposed to continuous freeze–thaw cycles; the variations in concentrations of vitamin D metabolites ranged between 15 and 60%. The overlapping peaks of vitamin D, its epimers, and its isobar (7αC4) were resolved using chromatographic separation. There were significant differences in the concentrations of all metabolites of vitamin D between the DDD and SDL mice. Between the groups SDD (control) and SDL, a significant difference in the concentrations of 3-epi-25OHD was noted, where C3 epimer was about 30% higher in SDL group while no significant differences were noted in the concentrations of vitamin D, 25OHD, 1α25(OH)₂D, and 7αC4 between SDD and SDL group. Conclusions: A validated method, combined with a simple extraction technique, for the sensitive LC-MS/MS determination of vitamin D metabolites is described here. The method can eliminate the interferences in LC-MS/MS analysis caused by the overlapping epimer and isobar due to them having the same molecular weights as 25OHD. The validated method was applied to mouse serum samples. It was concluded that a standard-vitamin D diet causes an increase in the proportion of all the vitamin D metabolites and C3 epimers and isobar, while UV light has no pronounced effect on the concentrations of the majority of the vitamin D metabolites except 3-epi-25OHD. Further studies are required to confirm this observation in humans and to investigate the biochemical pathways related to vitamin D’s metabolites and their epimers.     

Investigation of ageing effects on the electrical properties of polyaniline/silver nanocomposites

Polyaniline(PANI)/Ag nanocomposites, synthesized by incorporation of separately prepared silver nanoparticles in 1-methyl-2-pyrrolidinone(NMP) solution of PANI, have been aged at the accelerated temperature of 120 oC to simulate a storage period of 2 years at 25 oC. The accelerated ageing of these materials is done by using the activation energy calculated from data collected using heat flow calorimetry (HFC). The impedance spectroscopic studies of NMP plasticized aged nanocomposite films suggest a microphase separation into reduced and oxidized repeat units. There is crosslinking of the PANI films during ageing thereby obstructing the charge transfer between PANI chains and silver nanoparticles. As a result, the resistivity is increased.     

Genomic and biochemical approaches in the discovery of mechanisms for selective neuronal vulnerability to oxidative stress

Background  

Oxidative stress (OS) is an important factor in brain aging and neurodegenerative diseases. Certain neurons in different brain regions exhibit selective vulnerability to OS. Currently little is known about the underlying mechanisms of this selective neuronal vulnerability. The purpose of this study was to identify endogenous factors that predispose vulnerable neurons to OS by employing genomic and biochemical approaches.     

Alkyl Enol Ethers: Development in Intermolecular Organic Transformation

Alkyl enol ethers (AEE) are versatile synthetic intermediates with a unique reactivity pattern. This review article summarizes the synthesis of AEE as well as its reactivity and how enol ether undergoes intermolecular reactions for various bond formation, leading to the construction of several useful organic molecules. The synthetic applications of alkyl enol ethers towards intermolecular bond-forming reactions include metal-catalyzed reactions, cycloaddition and heterocycle formation as well as rwactions in the field of natural products synthesis. The achievement of these impressive transformations prove the countless synthetic potential of AEE. The main objective of this review is to bring attentiveness among synthetic chemists to show how AEE extensively can be used to react with both electrophiles as well as nucleophiles, thereby behaving as an ambiphilic reactant. We trust that the unique reactivity pattern of alkyl enol ethers and the fundamental mechanistic idea can attract chemists in AEE chemistry. Exclusively, intermolecular reactions of AEE with other functionalized moieties have not been reviewed to the best of our knowledge.     

Diphenylphosphorylated PEG (DPPPEG) as a new support for generation of nano-Pd(0) as catalyst for carbon–carbon bond formation via copper-free Sonogashira and homocoupling reactions of aryl halides in PEG

In this study, synthesis and application of diphenylphosphorylated PEG₂₀₀ (DPPPEG₂₀₀) are described. Herein, we report a very simple procedure for the preparation of DPPPEG₂₀₀ as a stable solid through the reaction of PEG₂₀₀ with ClPPh₂. This compound was used as a very suitable ligand for the in situ generation of nano-Pd(0) particles through its reaction with PdCl₂ as a pre-catalyst. Isolation of this catalyst is very simple through addition of diethyl ether to the reaction mixture and centrifugations. Full characterization of the nano-Pd(0)/DPPPEG200 was performed by XRD spectra, UV–Vis spectra, and also by TEM image. This nano-complex was used as an efficient catalyst for copper-free Sonogashira and homocoupling reactions of aryl halides. The sonogashira reaction of aryl halides was conducted at 80 °C in PEG. However, the homocoupling reaction was performed at 100 °C for aryl iodides and activated aryl bromides and at 130 °C for deactivated aryl bromides and aryl chlorides in PEG. The catalyst was recovered and recycled for four consecutive runs.     

Daphne mucronata-mediated phytosynthesis of silver nanoparticles and their novel biological applications,compatibility and toxicity studies

This contribution reports the biosynthesis of silver nanoparticles (AgNPs) using aqueous leaf extracts of D. mucronata and their diverse applications. Synthesized AgNPs were characterized using diverse techniques, i.e. UV, XRD, EDS, SEM, TEM, FTIR and TGA/DTA. These techniques confirmed the authenticity of the synthesized nanoparticles. The bimodulated AgNPs revealed the highest radical scavenging potential, i.e. 86.4% relative to plant extract at 600?μg/ml. Escherichia coli was found to be the most susceptible strain to AgNPs. Growth of vancomycin-resistant Staphylococcus aureus was also inhibited. Hemolytic activity revealed negligible hemolysis, indicating the biocompatible nature of biomodulated AgNPs. Furthermore, no mutagenic properties were shown by the biogenic AgNPs. Synthesized nanoparticles possessed promising insecticidal potential and had no phytotoxic activity. No haemagglutination was observed for biogenic AgNPs.     

Nifuroxazide Mitigates Angiogenesis in Ehlrich’s Solid Carcinoma: Molecular Docking,Bioinformatic and Experimental Studies on Inhibition of Il-6/Jak2/Stat3 Signaling

Nifuroxazide is an antidiarrheal medication that has promising anticancer activity against diverse types of tumors. The present study tested the anticancer activity of nifuroxazide against Ehrlich’s mammary carcinoma grown in vivo. Furthermore, we investigated the effect of nifuroxazide on IL-6/jak2/STAT3 signaling and the possible impact on tumor angiogenesis. The biological study was supported by molecular docking and bioinformatic predictions for the possible effect of nifuroxazide on this signaling pathway. Female albino mice were injected with Ehrlich carcinoma cells to produce Ehrlich’s solid tumors (ESTs). The experimental groups were as follows: EST control, EST + nifuroxazide (5 mg/kg), and EST + nifuroxazide (10 mg/kg). Nifuroxazide was found to reduce tumor masses (730.83 ± 73.19 and 381.42 ± 109.69 mg vs. 1099.5 ± 310.83) and lessen tumor pathologies. Furthermore, nifuroxazide downregulated IL-6, TNF-α, NFk-β, angiostatin, and Jak2 proteins, and it also reduced tumoral VEGF, as indicated by ELISA and immunohistochemical analysis. Furthermore, nifuroxazide dose-dependently downregulated STAT3 phosphorylation (60% and 30% reductions, respectively). Collectively, the current experiment shed light on the antitumor activity of nifuroxazide against mammary solid carcinoma grown in vivo. The antitumor activity was at least partly mediated by inhibition of IL-6/Jak2/STAT3 signaling that affected angiogenesis (low VEGF and high angiostatin) in the EST. Therefore, nifuroxazide might be a promising antitumor medication if appropriate human studies will be conducted.     

Photocatalytic degradation of benzothiophene by a novel photocatalyst,removal of decomposition fragments by MCM-41 sorbent

Research on Chemical Intermediates - In this study, a catalyst was synthesized by introduction of ZnO onto the surface of FSM-16 catalyst support (ZnO/FSM-16). Impregnation of catalyst support by...     

Asymptotic Behavior of Eigenvalues of Variance-Covariance Matrix of a High-Dimensional Heavy-Tailed Lévy Process

Methodology and Computing in Applied Probability - In this paper, we study the limiting behavior of eigenvalues of the variance-covariance matrix of a random sample from a multivariate subordinator...