Susceptibility Spectra Research Articles

Preparation and Characterization of Schiff Base Ligand Complexes (Dimedone With Thiourea)

In this study, eight complexes of this group were prepared by reacting the new ligand prepared from the reaction of dimedone with thiourea with metal chlorides of divalent (Mn, Co, Ni, Cu ,Zn, Cd) and trivalent (Fe, Cr) transition elements. These complexes were characterised by distinctive colours, melting points and solubility, and from the diagnostic results obtained, it was found that the ligand.(1E,5E)-5-carbamothioylimino)-3,3-dimethylcyclohexylidene) thiourea(L2) , that behave as dodecameric ligands with the metal ion, to which they bind through two amine groups. The octahedral shape of the complexes was suggested by IR, UV-visible, molar electrical conductivity, and magnetic susceptibility spectra, all of which indicated paramagnetic properties except for Zn and Cd, which have diamagnetic properties, and molar conductivity showed that all complexes are non-electrolytic except for Fe and Cr. The molecular formula of the complexes forming the group was determined by elemental analysis, where the elemental percentages matched the proposed molecular formula. The results measured the biological efficacy against pathogenic bacteria of the complexes showed varying efficacy. The results of antioxidant efficacy measurement using ethanol showed varying efficacy and were compared with gallic acid using DPPH as a free radical and gave different IC50 values. Density Functional Theory (DFT) measurement results showed that the chemical properties of the prepared complexes were consistent with the results of the practical part.

ANTIMICROBIAL, ANTIOXIDANT AND CYTOTOXICITY STUDY OF Cu(II), Zn(II), Ni(II), AND Zr(IV) COMPLEXES CONTAINING O, N DONOR SCHIFF BASE LIGAND

Objective: The aim of the research is to synthesize and characterize Cu(II), Zn(II), Ni(II), and Zr(IV) complexes with a Schiff base ligand, and evaluate their antibacterial and antioxidant properties. Methods: The ligand was synthesized by refluxing salicylaldehyde with o-phenylenediamine in ethanol, forming a yellow-orange product. The complexation reaction involved stirring ethanolic solutions of Zn(II), Cu(II), Ni(II), or Zr(IV) salts with a Schiff base ligand. Thermal decomposition of Zn(II), Cu(II), Ni(II), and Zr(IV) complexes was analyzed under nitrogen, heating at 30 °C/min, measuring weight loss from ambient temperature to 800 °C. The antibacterial activity, antioxidant properties, and cytotoxicity of the synthesized compounds wereexamined using reported methods. Results: Cu(II), Zn(II), Ni(II), and Zr(IV) complexes with a Schiff base ligand were synthesized. Analyzed through Fourier-transform infrared spectroscopy (FTIR), Ultraviolet-visible (UV-vis) and physiochemical tests and confirmed the structures. Magnetic susceptibility and electronic spectra suggested geometries, supported by thermogravimetric data. Antibacterial tests revealed complexes had higher activity than ligands, and also showed antioxidant properties. Conclusion: Cu(II), Zn(II), Ni(II), and Zr(IV) Schiff base complexes were synthesized, showing tetrahedral or square planar geometries. They exhibited thermal stability and strong antibacterial activity, outperforming the ligand alone.

Microwave susceptibility analysis of ultrafast moment dynamics in a multicore magnetic nanoparticle system

Room-temperature magnetization dynamics of multicore magnetic nanoparticles often account for intrinsic dipolar magnetism to behave as a single macrospin at low-frequency regime. Either magnetic particle imaging or hyperthermia benefits from the resulting superparamagnetism in terms of nonlinear magnetization response and relaxation losses at frequencies where the rotation of magnetic moments dominates over Brownian motion for a given sinusoidal field. For this situation, spontaneous thermal relaxation (in the absence of external fields) of each composing particle moment within the cluster is critical to define effective Néel time constant and may intersect with ferromagnetic resonance (FMR) at GHz range. Here, we performed broadband AC susceptometry on both immobilized single-core and multicore iron-oxide nanoparticles up to 26.5GHz under DC bias fields. For each solid sample, we confirmed FMR frequency, where large single-core nanoparticle systems demonstrated typical resonance blueshift as DC field increased. Interestingly, high DC field induced the secondary satellite peak in the imaginary part of AC susceptibility spectra for the case of multicore nanoparticle systems. We further highlighted that a synchronous precession of the polarized macrospins under nonuniform effective fields was responsible for splitting FMR peaks at nearby microwave frequencies. Upon curve fitting of the field-dependent FMR frequency spectra, the Landau-Lifshitz-Gilbert-Kittel model later elaborates on the complex moment dynamics of multicore nanoparticle systems in correlation with distribution functions. Published by the American Physical Society 2024

Therapeutic Phage Candidates for Targeting Prevalent Sequence Types of Carbapenem-Resistant Escherichia coli.

Carbapenem-resistant Escherichia coli (CREC) is a global threat to public health; therefore, alternative treatment options are urgently needed. Bacteriophages have emerged as promising candidates for combating CREC infections. This study aimed to investigate the genetic basis of phage sensitivity in CREC by evaluating carbapenem resistance among multidrug-resistant (MDR) E. coli isolated in Daegu, South Korea and analyzing their sequence types (STs) with phage susceptibility spectra. Among the 60 MDR E. coli isolates, 80.4% were identified as CREC, with 77.0% demonstrating resistance to imipenem and 66.6% to meropenem. Moreover, 70 lytic E. coli bacteriophages were isolated from hospital sewage water and evaluated against those 60 E. coli isolates. The phages exhibited lytic activity of 33%-60%, with average titers ranging from 5.6 × 1012 to 2.4 × 1013 PFU/mL (Plaque-Forming Unit). Furthermore, multilocus sequence typing (MLST) analysis of the bacterial isolates revealed 14 distinct STs, mostly belonging to ST131, ST410, and ST648. Notably, the phage susceptibility spectra of ST73, ST13003, ST648, ST2311, ST167, ST405, ST607, ST7962, and ST131 were significantly different. Thus, the isolated phages can effectively lyse CREC isolates, particularly those with clinically dominant STs. Conversely, ST410 exhibited a 14.2%-87.14% susceptibility spectrum, whereas ST1139, ST1487, ST10, and ST206 did not lyse, suggesting the presence of more resistant STs. Future studies are warranted to identify the reasons behind this resistance and address it. Ultimately, this study will aid in developing focused treatments to address these pressing global health issues.

New Series of Ni(II), Cu(II), Zr(IV), Ag(I), and Cd(II) Complexes of Trimethoprim and Diamine Ligands: Synthesis, Characterization, and Biological Studies

New compounds series of [M(TMP)(en)]X·nH2O and [M(TMP)(PD)]X·nH2O, where M = Ni2+, Cu2+, Zr4+, Ag+, Cd2+, TMP = trimethoprim, en = ethylenediamine, PD = o-phenylene and X= Cl− or NO3−, were prepared. The compounds were characterized using techniques including melting points, conductance, elemental analysis, FTIR, NMR, and mass spectroscopy. FTIR spectra indicated TMP acted like a bi-dentate ligand, combining via the nitrogen atoms of azomethine and pyrimidine amino groups. Diamine ligands (en or o-PD) are coordinated via two nitrogen atoms. Prepared compounds showed monomeric behavior and adopted a 6-coordinate octahedral geometry based on magnetic susceptibility and UV spectra. Conductivity measurements revealed Zr(IV) compounds were 1:2 conductive, while Ag+ and Cd2+ were 1:1 conductive; Ni2+ and Cu2+ compounds were non-conductive. Antibacterial tests on compounds and ligands against Bacillus subtilis and Staphylococcus aureus demonstrated broad-spectrum antibacterial activity. The mixed metal compounds revealed an observable tendency of antibacterial activity in the order Zr > Cd = Ag > Cu, making Zr(IV) compounds the most biologically active among them against S. aureus (Gram-positive) while the same compounds showed less antibacterial activity against B. subtilis (Gram-negative) than the free ligand.

Multivariate analysis applied to X-ray fluorescence to assess soil contamination pathways: case studies of mass magnetic susceptibility in soils near abandoned coal and W/Sn mines

Determining the origin and pathways of contaminants in the natural environment is key to informing any mitigation process. The mass magnetic susceptibility of soils allows a rapid method to measure the concentration of magnetic minerals, derived from anthropogenic activities such as mining or industrial processes, i.e., smelting metals (technogenic origin), or from the local bedrock (of geogenic origin). This is especially effective when combined with rapid geochemical analyses of soils. The use of multivariate analysis (MVA) elucidates complex multiple-component relationships between soil geochemistry and magnetic susceptibility. In the case of soil mining sites, X-ray fluorescence (XRF) spectroscopic data of soils contaminated by mine waste shows statistically significant relationships between magnetic susceptibility and some base metal species (e.g., Fe, Pb, Zn, etc.). Here, we show how qualitative and quantitative MVA methodologies can be used to assess soil contamination pathways using mass magnetic susceptibility and XRF spectra of soils near abandoned coal and W/Sn mines (NW Portugal). Principal component analysis (PCA) showed how the first two primary components (PC-1 + PC-2) explained 94% of the sample variability, grouped them according to their geochemistry and magnetic susceptibility in to geogenic and technogenic groups. Regression analyses showed a strong positive correlation (R2 > 0.95) between soil geochemistry and magnetic properties at the local scale. These parameters provided an insight into the multi-element variables that control magnetic susceptibility and indicated the possibility of efficient assessment of potentially contaminated sites through mass-specific soil magnetism.

Synthesis, Characterization, Antimicrobial and Cytotoxic Investigations of Some Transition Metal(II) Complexes with Tridentate Schiff Base Derived from Pyrrolopyrimidine

A Schiff base pyrrolopyrimidine-hydrazide-m-chlorobenzaldehyde (HPPHmCB) was synthesized via condensation reaction between a pyrrolopyrimidinehydrazide and 3-chlorobenzaldehyde and its transition metal(II) complexes complexes followed by the characterization and electrochemical analysis. The magnetic susceptibility, electrolytic conductivity, elemental analysis, FT-IR, electronic absorption, ESR and PMR spectra were employed to elucidate the structural properties. The Schiff base HPPHmCB ligand acts as a tridentate N,N,N donor and produces complexes of type [M(PPHmCB)2], which exhibit a square planar geometry for Pd(II) complex, tetrahedral for Hg(II), Cd(II) and Zn(II) complexes and octahedral geometry for Mn(II), Cu(II), Fe(II), Co(II) and Ni(II) complexes. The minimum inhibitory concentration (MIC) approach was used to screen the in vitro antibacterial and antifungal activities of synthesized Schiff base HPPHmCB ligand and its metal(II) complexes. The results showed that the significant microbial activities by both ligand and its transition metal(II) complexes. Moreover, in vitro cytotoxicity properties of Schiff base HPPHmCB ligand and its metal(II) complexes were also investigated against Artemia salina using the brine shrimp bioassay.

Magnetic-field dependence of the magnetic dynamics of barium hexaferrite nanoplatelet suspensions

Because of their unique structural and magnetic properties, ferrofluid suspensions consisting of barium hexaferrite nanoplatelets have been in the spotlight of intensive research. Analysis of the dynamic magnetic susceptibility spectra can elucidate both of these properties using the magnetic-field dependence of the Brownian relaxation mechanism. Applying a small probe field and uniform static bias fields in different configurations, the effect of single particles and collective behaviour is distinctly separated. The importance of considering magnetic interparticle interactions is illustrated by comparing models neglecting or considering such interactions, highlighting limitations considering particle concentration, interaction and excitation-field strengths.

Static and dynamic magnetic characteristics in concentric permalloy nanorings

Magnetic nanodisks and nanorings have been focus of attention for quite some time due to their applicability in magnetic memory devices. In this paper, static and dynamic magnetic properties of Permalloy concentric thin ring nanostructures are reported as a function of the number of rings by using micromagnetic simulations. The maximum outer radius (R) and thickness (t) of the concentric rings are fixed at 100 nm and 20 nm respectively. The distance between any two neighbouring rings is always maintained equal to the width of each ring while the number of nanorings is increased starting from one to five. In-plane magnetic hysteresis loops show that in all cases, the remanence and coercivity values are found to be almost zero while vortex state is exhibited with opposite helicity in adjacent nanorings. When the number of nanorings reach five, the narrowest hysteresis loop is observed with almost no hysteresis at all. Dynamic susceptibility spectra was computed by relaxing the system from a out of plane saturated state followed by an in-plane excitation using a small field pulse. In most of the cases, the in plane magnetic field pulse excites azimuthal spin wave modes. The resonance frequency corresponding to these excitation modes depends on the remanent configuration and the number of peaks increase with increment in the number of rings. The ferromagnetic resonance mode that is common for all the samples considered, moves towards lower frequency with increase in number of concentric rings.

From Single-Particle to Collective Dynamics in Supercooled Liquids.

It has been recognized recently that the considerable difference between photon correlation (PCS) and dielectric (BDS) susceptibility spectra arises from their respective association with single-particle and collective dynamics. This work presents a model that captures the narrower width and shifted peak position of collective dynamics (BDS), given the single-particle susceptibility derived from PCS studies. Only one adjustable parameter is required to connect the spectra of collective and single-particle dynamics. This constant accounts for cross-correlations between molecular angular velocities and the ratio of the first- and second-rank single-particle relaxation times. The model is tested for three supercooled liquids, glycerol, propylene glycol, and tributyl phosphate, and is shown to provide a good account of the difference between BDS and PCS spectra. Because PCS spectra appear to be rather universal across a range of supercooled liquids, this model provides a first step toward rationalizing the more material-specific dielectric loss profiles.

Dual imaging agent for magnetic particle imaging and computed tomography.

Magnetic particle imaging (MPI) is a novel biomedical imaging modality that allows non-invasive, tomographic, and quantitative tracking of the distribution of superparamagnetic iron oxide nanoparticle (SPION) tracers. While MPI possesses high sensitivity, detecting nanograms of iron, it does not provide anatomical information. Computed tomography (CT) is a widely used biomedical imaging modality that yields anatomical information at high resolution. A multimodal imaging agent combining the benefits of MPI and CT imaging would be of interest. Here we combine MPI-tailored SPIONs with CT-contrast hafnium oxide (hafnia) nanoparticles using flash nanoprecipitation to obtain dual-imaging MPI/CT agents. Co-encapsulation of iron oxide and hafnia in the composite nanoparticles was confirmed via transmission electron microscopy and elemental mapping. Equilibrium and dynamic magnetic characterization show a reduction in effective magnetic diameter and changes in dynamic magnetic susceptibility spectra at high oscillating field frequencies, suggesting magnetic interactions within the composite dual imaging tracers. The MPI performance of the dual imaging agent was evaluated and compared to the commercial tracer ferucarbotran. The dual-imaging agent has MPI sensitivity that is ∼3× better than this commercial tracer. However, worsening of MPI resolution was observed in the composite tracer when compared to individually coated SPIONs. This worsening resolution could result from magnetic dipolar interactions within the composite dual imaging tracer. The CT performance of the dual imaging agent was evaluated in a pre-clinical animal scanner and a clinical scanner, revealing better contrast compared to a commercial iodine-based contrast agent. We demonstrate that the dual imaging agent can be differentiated from the commercial iodine contrast agent using dual energy CT (DECT) imaging. Furthermore, the dual imaging agent displayed energy-dependent CT contrast arising from the combination of SPION and hafnia, making it potentially suitable for virtual monochromatic imaging of the contrast agent distribution using DECT.

Interplay between steric and hydrodynamic interactions for ellipsoidal magnetic nanoparticles in a polymer suspension.

Magnetic nanoparticles couple to polymeric environments by several mechanisms. These include van der Waals, steric, hydrodynamic and electrostatic forces. This leads to numerous interesting effects and potential applications. Still, the details of the coupling are often unknown. In a previous work, we showed that, for spherical particles, hydrodynamic coupling alone can explain experimentally observed trends in magnetic AC susceptibility spectra [P. Kreissl, C. Holm and R. Weeber, Soft Matter, 2021, 17, 174-183]. Non-spherical, elongated particles are of interest because an enhanced coupling to the surrounding polymers is expected. In this publication we study the interplay of steric and hydrodynamic interactions between those particles and a polymer suspension. To this end, we obtain rotational friction coefficients, relaxation times for the magnetic moment, and AC susceptibility spectra, and compare these for simulations with and without hydrodynamic interactions considered. We show that, even if the particle is ellipsoidal, its hydrodynamic interactions with the surrounding polymers are much stronger than the steric ones due to the shape-anisotropy of the particle.

Influence of intramolecular dynamics on the relaxation spectra of simple liquids.

The shape of the structural relaxation peak in the susceptibility spectra of liquids is of great interest, as it promises to provide information about the distribution of molecular mobilities and dynamic heterogeneity. However, recent studies suggest a generic shape of this peak near the glass transition temperature irrespective of the liquid under investigation, which somehow reduces the information contained in the peak shape. By contrast, at higher temperatures, say, around the melting point, the situation is different and the peak shape varies strongly between different liquids. In this study, we investigate molecules with a ring-tail structure and address the question how intramolecular dynamics influences the peak shape at these temperatures. Using depolarized light scattering and dielectric spectroscopy, we observe a bimodal relaxation, which we attribute to the fact that the reorientation of the ring group to some extent decouples from the rest of the molecule. This shows that the relaxation spectra are sensitive to details of the molecular motions at high temperatures, whereas in the supercooled state this microscopic information seems to give way to a generic shape, probably due to the onset of cooperativity which extends across different intramolecular moieties.

Remote Sensing of the Nano-Rheological Properties of Soft Materials Using Magnetic Nanoparticles and Magnetic AC Susceptometry.

We have developed a nano-rheological characterization tool to extract the frequency- and scale-dependent rheological properties of soft materials during oral processing. Taking advantage of AC susceptometry, the dynamic magnetization of magnetic nanoparticles blended in the matrix material is measured. The magnetic AC susceptibility spectra of the particles are affected by the viscosity and mechanical modulus of the matrix material and provide the rheological properties of the matrix. Commercially available iron-oxide magnetic nanoparticles with 80 and 100 nm particle sizes are used as tracers in the frequency range of 1 Hz-10 kHz. The AC susceptibility is measured using two differentially connected coils, and the effects of the sample temperature and distance with respect to the detection coils are investigated. The developed measurement setup shows the feasibility of remote nano-rheological measurements up to 2 cm from the coil system, which can be used to, e.g., monitor the texture of matrix materials during oral processing.

Synthesis, Characterization, and Biological Activity of Mixed ligand Complexes from 8-Hydroxyquinoline and new Ligand for β-Enaminone

The synthesized ligand [4-chloro-5-(N-(5,5-dimethyl-3-oxocyclohex-1-en-1-yl)sulfamoyl)-2-((furan-2-ylmethyl)amino)benzoic acid] (H2L1) was identified utilizing Fourier transform infrared spectroscopy (FT-IR), 1 H, 13 C – NMR, (C.H.N), Mass spectra, UV-Vis methods based on spectroscopy. To detect mixed ligand complexes, analytical and spectroscopic approaches such as micro-analysis, conductance, UV-Visible, magnetic susceptibility, and FT-IR spectra were utilized. Its mixed ligand complexes [M(L1)(Q)Cl2] [ where M= Co(II), Ni(II), and Cd(II)] and complexes [Pd(L1)(Q)] and [Pt(L1)(Q)Cl2]; [H2L1] =β-enaminone ligand =L1 and Q= 8-Hydroxyquinoline = L2]. The results showed that the complexes were synthesised utilizing the molar ratio M: L1:L2 (1 :1 :1). The formation of six-coordinate octahedral geometry was proposed for metal complexes Co (II), Ni (II), Cd (II), and Pt (IIII), while the Pd (II) complex was square planar. By using the agar well diffusion method, the ligands and complexes were evaluated for antibacterial activity against Staphylococcus aureus, Escherichia coli. The studies demonstrate that the ligand and its complexes have variable activity against the bacterial types, Some of the complexes had an effect on bacteria, while others had less inhibitory action than the ligand. Also, the produced ligand and its metal complexes have been tested for fungi (Candida albicans );the complexes exhibited suppressing activity against fungi compared to the ligand prepared from them. Keywords: β-enaminones, 5,5-dimethylcyclohexane-1,3-dione , Furosemide, Mixed-ligand complexes, 8-Hydroxyquinoline.

Synthesis and characterization of some novel complexes of Pd(II) and Pt(II) with bidentate Schiff base ligand

A novel series of Pd(II) and Pt(II) complexes with Schiff base ligand 2-(pyridine-2′-carbaldehydeimino) pyrazine have been synthesized and characterized by micro elemental analysis, molar conductivity, magnetic susceptibility, FTIR, NMR and electronic absorption spectra. General molecular formula of the complexes has been found to be [M(L)(B)2] where M= Pd(II) and Pt(II) cations L=Schiff base and B= bases such as water, ammonia, pyridine and ɑ-picoline. All the bases contain nitrogen and oxygen as their donor sites. The molar conductance values of metal complexes suggest their electrolytic nature. On the basis of elemental analysis, molar conductance, magnetic moment measurements and spectral data complexes were proposed to be square planar.

Synthesis and Physicochemical Studies for Novel Bioactive Metal Complexes of Macrolide Antibiotic Tylosin

Tylosin is a well-established antibiotic that has been widely employed in human and veterinary medicines. It can act as a potential ligand binding metal ions due to various donor atoms in the structure. Our study on the complexation of various metal ions with tylosin ligand revealed that they preferably coordinate with mycaminose fragment to establish Novel trends complexes. Tylosin ligand (TYS) behaves as bidentate for complexation with different metal ions such as Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II). Various essential metal complexes of tylosin were synthesized and characterized by techniques such as UV, IR, Elemental analysis, magnetic susceptibility and ESR spectra of Cu(II) complex. These techniques are used to know their geometries and mode of bonding, with stoichiometry, 2:2 (M:L). Thermal analysis (TGA and DTA) of ligands and their metal complexes were carried out to distinguish between the coordinate and hydrate solvents and to estimate the stability ranges, peak temperatures. The thermodynamic parameters, such as activation energy (ΔE*), the enthalpy of activation (ΔH*), entropy of activation (ΔS*) and Gibbs free energy (ΔG*) are calculated and discussed. Some tylosin complexes show higher activity than tylosin for some bacterial and fungal strains. Low concentration value of minimum inhibitory concentration (MIC) results is 15.625 μg/ml for both complexes [Zn2(TYS)2Cl2(H2O)4]·25H2O and [Cu2(TYS)2Cl2(H2O)4]·25H2O with B. cereus genus maybe a valuable data used to produce novel therapeutic agent. This study constitutes several essential aspects for future research on tylosin metal complexes as antibacterial assessment and as potential medicinal agents.

Synthesis and Physicochemical Studies for Novel Bioactive Metal Complexes of Macrolide Antibiotic Tylosin

Tylosin is a well-established antibiotic that has been widely employed in human and veterinary medicines. It can act as a potential ligand binding metal ions due to various donor atoms in the structure. Our study on the complexation of various metal ions with tylosin ligand revealed that they preferably coordinate with mycaminose fragment to establish Novel trends complexes. Tylosin ligand (TYS) behaves as bidentate for complexation with different metal ions such as Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II). Various essential metal complexes of tylosin were synthesized and characterized by techniques such as UV, IR, Elemental analysis, magnetic susceptibility and ESR spectra of Cu(II) complex. These techniques are used to know their geometries and mode of bonding, with stoichiometry, 2:2 (M:L). Thermal analysis (TGA and DTA) of ligands and their metal complexes were carried out to distinguish between the coordinate and hydrate solvents and to estimate the stability ranges, peak temperatures. The thermodynamic parameters, such as activation energy (ΔE*), the enthalpy of activation (ΔH*), entropy of activation (ΔS*) and Gibbs free energy (ΔG*) are calculated and discussed. Some tylosin complexes show higher activity than tylosin for some bacterial and fungal strains. Low concentration value of minimum inhibitory concentration (MIC) results is 15.625 μg/ml for both complexes [Zn2(TYS)2Cl2(H2O)4]·25H2O and [Cu2(TYS)2Cl2(H2O)4]·25H2O with B. cereus genus maybe a valuable data used to produce novel therapeutic agent. This study constitutes several essential aspects for future research on tylosin metal complexes as antibacterial assessment and as potential medicinal agents.

Synthesis, Theoretical Study, and Biological Evaluation of Some Metal Ions with Ligand "Methyl -6-[2-(4-Hydroxyphenyl) -2-((1-Phenylethylidene) Amino) Acetamido] -2,2-Dimethyl-5—Oxo-1-Thia-4-Azabicyclo [3.2.0] Heptane-3-Carboxyylate

Schiff base (methyl 6-(2- (4-hydroxyphenyl) -2- (1-phenyl ethyl ideneamino) acetamido) -3, 3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0] heptane-2-carboxylate)Co(II), Ni(II), Cu (II), Zn (II), and Hg(II)] ions were employed to make certain complexes. Metal analysis M percent, elemental chemical analysis (C.H.N.S), and other standard physico-chemical methods were used. Magnetic susceptibility, conductometric measurements, FT-IR and UV-visible Spectra were used to identified. Theoretical treatment of the generated complexes in the gas phase was performed using the (hyperchem-8.07) program for molecular mechanics and semi-empirical computations. The (PM3) approach was used to determine the heat of formation (ΔH˚f), binding energy (ΔEb), and total energy (ET) for ligands and metal complexes at 298 ᴼK. To explore the reactive sites of the compounds, the electrostatic potential of the ligand (L) was computed. PM3 was used to calculate the vibrational frequencies of the ligand (L) and its metal complexes, which were then compared to experimental data. The antibacterial activity of (L) and its metal complexes against three harmful microorganisms were examined: Staphylococcus aureus (gram positive), Echerchia coli (gram negative), and Candida albicans.

Hyperspectral CARS microscopy and quantitative unsupervised analysis of deuterated and non-deuterated fatty acid storage in human cells.

Coherent anti-Stokes Raman scattering (CARS) implemented as a vibrational micro-spectroscopy modality eradicates the need for potentially perturbative fluorescent labeling while still providing high-resolution, chemically specific images of biological samples. Isotopic substitution of hydrogen atoms with deuterium introduces minimal change to molecular structures and can be coupled with CARS microscopy to increase chemical contrast. Here, we investigate HeLa cells incubated with non-deuterated or deuterium-labeled fatty acids, using an in-house-developed hyperspectral CARS microscope coupled with an unsupervised quantitative data analysis algorithm, to retrieve Raman susceptibility spectra and concentration maps of chemical components in physically meaningful units. We demonstrate that our unsupervised analysis retrieves the susceptibility spectra of the specific fatty acids, both deuterated and non-deuterated, in good agreement with reference Raman spectra measured in pure lipids. Our analysis, using the cell-silent spectral region, achieved excellent chemical specificity despite having no prior knowledge and considering the complex intracellular environment inside cells. The quantitative capabilities of the analysis allowed us to measure the concentration of deuterated and non-deuterated fatty acids stored within cytosolic lipid droplets over a 24 h period. Finally, we explored the potential use of deuterium-labeled lipid droplets for non-invasive cell tracking, demonstrating an effective application of the technique for distinguishing between cells in a mixed population over a 16 h period. These results further demonstrate the chemically specific capabilities of hyperspectral CARS microscopy to characterize and distinguish specific lipid types inside cells using an unbiased quantitative data analysis methodology.