In vitro antimicrobial activity and DNA cleavage studies: synthesis and characterization of novel M(II) complexes with tridentate [ONO] donor Schiff base ligand derived from phenylpropane hydrazide

Three new ternary complexes of general formulation [M(L)​n] (1-​3)​, where L = N'-​(5-​chloro-​2-​hydroxybenzylidine)​-​3-​phenylpropane hydrazide; n = 2; M = Cu, Ni, Zn, complexes are synthesized, characterized by various physicochem. and UV-​Vis, FT-​IR, 1H NMR and ESI-​MS spectroscopic methods. The Cyclic voltammetry show a quasi-​reversible cyclic voltammetric response due to one electron Cu(II)​/Cu(I) redn. near 100 mV (vs. SCE) in DMF-​0.1 M KCl. All the compds. were screened for their in-​vitro antibacterial activity against Gram pos. and Gram neg. bacterial strains. Among them, Cu complex showed good activity against all microbes. The copper complex shows moderate chem. nuclease activity in the presence of MPA as a reducing agent

Platelet aggregation inhibitory activity and radical scavenging activity of Spondias mangifera Willd

The dry powder of Spondias mangifera Willd. fruits was sequentially extracted with hexane, chloroform, ethyl acetate, acetone and methanol. The extract yield increased with increase in the polarity of the solvent. The ethyl acetate extract showed potential platelet aggregation inhibitory activity with IC50 value of 0.33 mg and 0.43 mg for antagonists like collagen and ADP respectively. The methanol extract also revealed high platelet aggregation inhibition with very low IC50 value of 0.26 mg and 0.35 mg for antagonists like collagen and ADP respectively. Methanol extract showed high DPPH radical scavenging activity compared to other extracts.</jats:p

Novel ligand 1-Benzyl-3-(4-ethyl-pyridin-2-yl)-thiourea and Cu (I) complexes: DNA interaction, antibacterial and thermal studies

The new ligand 1-Benzyl-3-(4-ethyl-pyridin-2-yl)-thiourea (1), and two copper(I) complexes Cu(4ETU)2Cl (2), Cu(4ETU)(B)Cl (3) where 4ETU=1-Benzyl-3-(4-ethyl-pyridin-2-yl)-thiourea, B is a N,N-donor heterocyclic base, viz. 1,10-phenanthroline (phen, 3), were synthesized, characterized by various physico-chemical and spectroscopic techniques. The elemental analysis suggests that the stoichiometry to be 1:2 (metal:ligand) for 2 and 1:1:1 (metal:ligand:B) for 3. PXRD analysis provides the crystalline nature of the metal complexes. IR data coupled with electronic spectra and molar conductance values suggest that the complex 2 shows the presence of a trigonal planar geometry and the complex 3 shows the presence of a tetragonal geometry about the Cu(I) centre. Binding interactions of the complexes with calf thymus (CT) DNA have been investigated by absorption, emission, DNA thermal denaturation and viscosity studies. The phen complex displays significant binding propensity to the CT DNA giving an order: 3 (phen) &gt; 2. Complex 3 shows efficient oxidative cleavage of SC-DNA in the presence of H2O2 involving hydroxyl radical species as evidenced from the control data showing inhibition of DNA cleavage in the presence of DMSO and KI. The compounds were screened for their in vitro anti-bacterial activity using Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus) and Gramnegative bacteria (Esherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia). Complexes 2 &amp; 3 exhibits higher antibacterial activity against Gram-positive bacteria than the Gram-negative bacteria. Antibacterial activity is higher when thiourea coordinates to metal ion than the thiourea alone. The thermogram of complex 2 exhibits single step and complex 3 exhibits two step decomposition behavior

Fabrication, mechanical and wear properties of Aluminum (Al6061)-silicon carbide-graphite Hybrid Metal Matrix Composites

In recent times, the use of aluminum alloy-based Hybrid Metal Matrix Composites (HMMCs) is being increased in aerospace and automotive applications. HMMCs compensate for the low desirable properties of each filler used. However, the mechanical properties of HMMCs are not well understood. In particular, microstructural investigations and wear optimization studies of HMMCs are not clear. Therefore, further studies are required. The present study is aimed at fabricating and mechanical and wear characterizing and microstructure investigating of Silicon Carbide (SiC) and Graphite (Gr) added in Aluminum (Al) alloy Al6061 HMMCs. The addition of SiC particles was in the range from 0 to 9 weight percentage (wt.%) in steps of 3, along with the addition of 1 wt.% Gr in powder form. The presence of alloying elements in the Al6061 alloy was identified using the Energy Dispersive X-Ray Analysis (EDX). The dispersion of SiC and Gr particles in the alloy was investigated using metallurgical microscope and Scanning Electron Microscopy (SEM). The gain in strength can be attributed to the growth in dislocation density. The nature of fracture was quasi-cleavage. The microstructure examination reveals the uniform dispersion of the reinforcement. Density, hardness, and Ultimate Tensile Strength values observed to be increased with increased contents of SiC reinforcement. Besides, wear studies were performed in dry sliding conditions. Optimization studies were performed to investigate the effect of parameters that affecting the wear. The sliding wear resistance was noticed to be improved concerning higher amounts of reinforcement leading to a decrease in delamination and adhesive wear. The predicted values for the wear rate have also been compared with the experimental results and good correlation is obtaine