Spectral Studies Research Articles

Integrated computational modeling and in-silico validation of flavonoids-Alliuocide G and Alliuocide A as therapeutic agents for their multi-target potential: Combination of molecular docking, MM-GBSA, ADMET and DFT analysis

Alliuocide class of compounds belong to flavonoids and were isolated from Allium cepa. Alliuocide are the key phytoconstituents of Allium cepa having biological activities like anticancer, antidiabetic, anti-allergic, metabolic, and inflammatory disorders, antibacterial as well as effective antioxidants against chronic diseases. However, after their isolation report, there was no further work done and a gap of about 10 years. Herein, the present study was carried out to cover the gap and to identify new lead candidates in drug discovery pipeline. Alliuocide A and G were screened against various antioxidant, antidiabetic, anticancer and antibacterial target proteins. Target based screening by molecular docking against different target receptor co-crystal structure revealed Alliuocide A as potential hit, these results were further demonstrated by MM-GBSA studies. Further optimization of both compounds was done by in silico absorption, distribution, metabolism, excretion and toxicity (ADMET) studies. Both compounds followed Lipinski's rule of five therefore safe for further in vivo studies. Finally spectral studies along with quantum descriptors were carried out by employing DFT method at 6–311 G (d,p) basis set. These quantum chemical parameters proved to be important mechanism for correlating the inhibition efficiency with molecular quatum parameters. All these studies help in designing of derivatives for better pharmacological potential.

Hexagonal Mo Bronze: Single Crystal Structures, Electrocatalytic Hydrogen Evolution, and Proton Conductivity.

Molybdenum trioxide (MoO3) is a well-known transition metal oxide that has drawn much attention as a functional material having numerous applications. However, a vast majority of studies have primarily focused on α-MoO3, the thermodynamically stable polymorph of MoO3. This present work encompasses the synthesis of single crystals of two metastable hexagonal MoO3 described by the formulas {Mn0.03Na0.01}@[Mo0.93VIMo0.07VO3] (1) and {Cu0.01Na0.01}@[Mo0.97VIMo0.03VO3] (2), their comprehensive structural characterization by single-crystal X-ray crystallography, and routine spectral and microscopic studies. Interestingly, compound 1 acts as an efficient electrocatalyst for the hydrogen evolution reaction (HER) as well as an effective proton conductor in comparison to the performance of compound 2. The HER activity of compound 1 is characterized by an overpotential of 340 mV@1 mA cm-2 and a low Tafel slope of 75 mV/decade. The catalyst (compound 1) displays a Faradaic efficiency of 88% with a turnover frequency of 2.9 s-1. The proton conductivity value of this compound (1) is determined to be 4.9 × 10-3 S cm-1 at 55 °C under 98% relative humidity; the relevant proton conduction is operated by the Grotthuss mechanism with an activation energy of 0.17 eV.

TEMPLATE-ENGINEERED TRIVALENT IRON AND CHROMIUM CONTAINING MACROCYCLIC COMPLEXES: CHARACTERIZATION AND IN VITRO STUDIES

A novel series of tetraaza macrocyclic complexes of biological importance was synthesized by “in situ” template reaction between triethylenetetramine and dibenzoylmethane in the presence of trivalent Fe and Cr metal salts in 1:1:1 molar ratio. These complexes are represented by molecular formula [M(C[Formula: see text]H[Formula: see text]N[Formula: see text]X]X2; [Formula: see text](III) and Cr(III); [Formula: see text], NO[Formula: see text], −OAc; C[Formula: see text]H[Formula: see text]N[Formula: see text] ligand. The reported complexes were characterized by using various physicochemical and spectroscopic techniques including elemental analyses, molar conductance, thermo-gravimetric analysis, FTIR, UV–Visible and mass spectral studies. The results obtained from analytical techniques and spectroscopic techniques together suggested the complexes have a square pyramidal geometry. Various computational studies were performed including molecular docking and modeling. Further, macrocyclic complexes were also screened for their “in vitro” antimicrobial activity against selected bacterial and fungal strains. The antioxidant activity of these complexes was also evaluated. Some of the complexes were found to possess remarkable antimicrobial activity and antioxidant activity. However, complex [Fe(C[Formula: see text]H[Formula: see text]N[Formula: see text](NO[Formula: see text]](NO[Formula: see text] was found to be most potent against selected bacterial and fungal strains. On the other hand, complex [Cr(C[Formula: see text]H[Formula: see text]N[Formula: see text](NO[Formula: see text]](NO[Formula: see text] was found to show best antioxidant activity with lowest value of IC[Formula: see text].

Excited Charge Separation in a π-Interacting Phenothiazine-Zinc Porphyrin-Fullerene Donor-Acceptor Conjugate.

We have designed, synthesized, and characterized a donor-acceptor triad, SPS-PPY-C60, that consists of a π-interacting phenothiazine-linked porphyrin as a donor and sensitizer and fullerene as an acceptor to seek charge separation upon photoexcitation. The optical absorption spectrum revealed red-shifted Soret and Q-bands of porphyrin due to charge transfer-type interactions involving the two ethynyl bridges carrying electron-rich and electron-poor substituents. The redox properties suggested that the phenothiazine-porphyrin part of the molecule is easier to oxidize and the fullerene part is easier to reduce. DFT calculations supported the redox properties wherein the electron density of the highest molecular orbital (HOMO) was distributed over the donor phenothiazine-porphyrin entity while the lowest unoccupied molecular orbital (LUMO) was distributed over the fullerene acceptor. TD-DFT studies suggested the involvement of both the S2 and S1 states in the charge transfer process. The steady-state emission spectrum, when excited either at porphyrin Soret or visible band absorption maxima, revealed quenched emission both in nonpolar and polar solvents, suggesting the occurrence of excited state events. Finally, femtosecond transient absorption spectral studies were performed to witness the charge separation by utilizing solvents of different polarities. The transient data was further analyzed by GloTarAn by fitting the data with appropriate models to describe photochemical events. From this, the average lifetime of the charge-separated state calculated was found to be 169 ps in benzonitrile, 319 ps in dichlorobenzene, 1.7 ns in toluene for Soret band excitation, and ∼320 ps for Q-band excitation in benzonitrile.

Photometric and Spectral Studies of a Group of Wolf-Rayet Galactic Stars. II. WC and WO Sequences

Photometric and Spectral Studies of a Group of Wolf-Rayet Galactic Stars. II. WC and WO Sequences

Spectral studies of thermally stable Dy3+/Sm3+ co-doped Li2Ba5W3O15 phosphors for warm white LEDs

In the current study, a series of Li2Ba5W3O15: RE3+ (RE = Dy, Sm) [LBW:Dy3+/Sm3+] phosphors were prepared using a high-temperature solid-state method. X-ray diffraction, Scanning electron microscopy with energy-dispersive x-ray analysis scans showed that the crystal form was consistent with the standard LBW and comprised small irregularly shaped particles. Diffuse reflectance spectral (DRS) data was utilized to calculate the band gaps. Fluorescence study shows that LBW material doped with Dy3+ and Sm3+ yield distinct colors at 496 nm (blue) for Dy3+ and 582 nm (green-yellow), 612 nm (yellow), and 669 nm (red) for Sm3+ when excited by near-ultraviolet (336 nm) light. The observation of energy transfer between Dy3+ and Sm3+ ions play a role in modifying the luminescence of LBW:Dy3+/Sm3+ co-doped phosphors. With a constant excitation wavelength (λ Ex), different levels of activator doping lead to a change in the emission colors from their neutral white light to a deep orange-red region for LBW:Dy3+/Sm3+ phosphors. The decay curves demonstrate a decrease in lifetime with an increase in the concentration of activator ions (Sm3+). For D3S5 phosphor, the temperature-dependent photoluminescence characteristics were analyzed under λ Ex = 336 nm excitation. The results indicate excellent luminescence thermal stability with an activation energy of 0.16 eV at λ Ex = 336 nm. With its low color-correlated temperature and good thermal stability, the prepared phosphor sample shows potential as a solid-state emitting phosphor that can be used with UV chip stimulation for warm white LED applications.

Innovation, structural inspection for new mixed complexes: DNA binding, biomedical applications and molecular docking approaches

2-Guanidinobenzimidazole (BIG) and Imidiazole (I) ligands were utilized to synthesize Cu(II), VO(II), Ag(I), and Pd(II) as mixed ligand complexes. All studied molecules were characterized through various spectral, analytical and computational studies to find out their chemical structure. TGA was applied to identify the occurrence of H2O molecules besides the mono-nuclear property of isolated complexes. These complexes were proved through DFT study to confirm the coordinating site that was proposed and displays the optimal three-dimensional structures of the studied compounds. The binding affinity of the tested complexes with CT-DNA has been tested through agarose gel, electronic spectroscopy and viscosity measurements. Furthermore, the studied molecules might bind to CT-DNA electrostatically through exterior contact, replacement, intercalation and groove surface binding with good affinity. In-vitro anti-bacterial, anti-fungi, cytotoxic and antioxidant activities are performed for all studied compounds. MOE-docking simulation results indicate promising inhibitory features of BIGIPd complexes, in agreement with in-vitro results.

Synthesis, characterisation and in vitro anticancer activity of conjugated protease inhibitor-silver nanoparticles (AgNPs-PI) against human breast MCF-7 and prostate PC-3 cancer cell lines.

The conjugated silver nanoparticles using biomolecules have attracted great attention of researchers because physical dimensions and surface chemistry play important roles in toxicity and biocompatibility of AgNPs. Hence, in the current study, synthesis of bio-conjugated AgNPs with protein protease inhibitor (PI) isolated from Streptomyces spp. is reported. UV-visible spectra of PI and AgNPs showed stronger peaks at 280 and 405nm, confirming the synthesis of conjugated AgNPs-PI. TEM and SEM images of AgNPs-PI showed spherical-shaped nanoparticles with a slight increase in particle size and thin amorphous layer around the surface of silver nanomaterial. Circular dichroism, FT-IR and fluorescence spectral studies confirmed AgNPs-PI conjugation. Conjugated AgNPs-PI showed excellent anticancer potential than AgNPs and protease inhibitor separately on human breast MCF-7 and prostate PC-3 cell lines. The findings revealed that surface modification of AgNPs with protein protease inhibitor stabilised the nanomaterial and increased its anticancer activity.

Enhancing photocatalytic efficiency of type II V2O5/TiO2 heterojunctions for malachite green dye using solar simulator irradiation

Photocatalytic responses and synergistic effects of V2O5, TiO2, and V2O5/TiO2 heterostructures with varied ratios have been investigated, revealing promising outcomes. The successful synthesis of nanostructures and heterostructures was verified through energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses. Notably, ultraviolet–visible spectroscopy and photoluminescence spectral studies confirmed that the optical band gap of V2O5/TiO2 heterostructures increases with higher TiO2 concentrations. These findings enhance our understanding of the agglomerated heterostructures of V2O5/TiO2, particularly with ratios of 1:1 and 1:3, showcasing potential applications in photocatalysis. Furthermore, their performance was subjected to Malachite Green dye degradation using a solar simulator, achieving an impressive efficiency of 93.29%. Additionally, the photocatalytic efficacy was assessed through reusability experiments over three cycles. Remarkably, the heterostructures exhibited stability across these cycles, suggesting their potential for extended use in diverse photocatalytic purposes. The importance of these results is the applicability of our fabricated V2O5/TiO2 heterostructures as a photocatalyst with high performance, especially in the realm of sustainable and efficient dye degradation processes.

Highly selective Gd(III) fluorimetric sensor based on thiosemicarbazone Scaffold: A dual function ensemble for fluorescence and naked eye sensing of CN− and H2PO4− anions

Sensing ions by colorimetric and fluorimetric methods has grown tremendously due to the great environmental concern. This paper reports the colorimetric and fluorescent studies of cation and anion sensing by two thiosemicarbazone-supported receptors: (E)-2-((8-hydroxyquinolin-2-yl)methylene) hydrazine-1-carbothioamide (H2qctsc) (1) and [Gd(Hqctsc)2]+ complex (2). Under irradiation at λex = 346 nm, the fluorescence sensing behavior of H2qctsc was investigated towards various metal ions (Na+, K+, Co2+, Cu2+, Cd2+, Cr3+, Fe2+, Fe3+, Al3+, Mn2+, Pb2+, Hg2+, Ni2+, Zn2+, Nd3+, Eu3+, Gd3+, Tb3+, Ho3+and Er3+) in DMSO medium. The chemosensor H2qctsc displayed a “Turn–Off” selective recognition towards Gd3+ ions through a 3.5-fold fluorescence quenching at 476 nm with the detection limit as low as 1.42 μM. It binds with Gd3+ in a 2:1 stoichiometric ratio. Further, the (1)-Gd3+ ensemble (2) exhibited a highly selective colorimetric and fluorimetric sensing for the biologically essential anions H2PO4− and CN− detecting the ions with a detection limit of 0.94 μM and 2.19 μM respectively, amongst a wide range of anions chosen. Colorimetric is a valuable technique since visual detection can give immediate qualitative information. In the present case, a naked eye color detection, i.e., yellow → colorless (H2PO4−) and yellow → red (CN−) by the ensemble, can add value to the sensor's employability in various fields. The coordination behavior of H2qctsc was examined in a highly aqueous medium (9:1 H2O: DMSO) by adopting the potentiometric and spectrophotometric methods, which revealed the formation of a very stable complex with a high formation constant (logβ = 24.75), demonstrating it as a potent chelator for Gd3+ ion. The stoichiometry of the complex was determined by Job's plot method, which confirmed the ML2-type complex. Additionally, a solid complex 2′ abbreviated as [Gd(Hqctsc)(qctsc)] was synthesized using the conventional method and was characterized by advanced spectroscopic techniques. The spectral studies of the synthesized complex further establish its high selective recognition towards H2PO4− and CN− ions. Density functional theory (DFT) studies confirmed the structure, bonding, spectra, and sensing mechanism of H2qctsc and the Gd-complex.

Heterocyclic fluorescent Schiff base chemosensors for the detection of Fe(III) and Cu(II) ions.

Two new Schiff bases were synthesized from 1-(2,4-dihydroxyphenyl)ethanone and pyridine derivatives. Both compounds were characterized using infrared, UV-Vis., 1H NMR, 13C NMR and mass spectral studies. Density functional theory (DFT) calculations were performed for both the Schiff bases with 6-31G(d, p) as the basis set. Vibrational frequencies calculated using the theoretical method were in good agreement with the experimental values. Both the Schiff bases were highly fluorescent in nature. The cation-recognizing profile of the compounds was investigated in aqueous methanol medium. The Schiff base 4-(1-(pyridin-4-ylimino)ethyl)benzene-1,3-diol (PYEB) was found to interact with Fe(III) and Cu(II) ions, whereas the Schiff base 4,4'-((pyridine-2,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(benzene-1,3-diol) (PDEB) was found to detect Cu(II) ions. The mechanism of recognition was established as combined excited state intramolecular proton transfer (ESIPT)-chelation-enhanced fluorescence (CHEF) effect and chelation-enhanced quenching (CHEQ) process for the detection of Fe(III) and Cu(II) ions, respectively. The stability constant of the metal complexes formed during the sensing process was determined. The limit of detection for Fe(III) and Cu(II) ions with respect to Schiff base PYEB was found to be 1.64 ×10-6 and 2.16 ×10-7M, respectively. With respect to Schiff base PDEB, the limit of detection for Cu(II) ion was found to be 4.54 ×10-4M. The Cu(II) ion sensing property of the Schiff base PDEB was applied in bioimaging studies for the detection of HeLa cells.

Structural behavior and surface layer modification of (E)-N'-((1H-indol-3-yl) methylene)-4-chlorobenzohydrazide: Spectroscopic, DFT, biomedical activity and molecular dynamic simulation against Candida Albicans receptor

The synthesis of (E)-N'-((1H-indol-3-yl) methylene)-4-chlorobenzohydrazide (IMCBH) (A2) was achieved by reacting indole-3-carboxyaldehyde with 4-chlorobenzohydrazide. Their different biological properties, including antibacterial and antifungal activities, were assessed. The synthesized heterocyclic compound was characterized by its TLC, melting point, FT-IR, 1H, and 13C NMR spectral studies. Biological studies were considered to predict the effect of ligand-DNA complexed behavior. The computational methods induce an important impact to on understanding the molecular and electronic behavior of spectrum heterocyclic compounds. Using the more widely used DFT methods, the structural and electronic behavior of the synthesized IMCBH were computed. Quantum chemical reactivity parameters were calculated to reveal the active site's behavior towards other electronic-system variety. TD-DFT level was performed to depict the UV–vis and ECD spectra. Further studies were performed on the designed organic layer of the tested compound, such as electronic band structure and DOS to investigate the surface electronic properties in charge distribution. Also, Forcite dynamics on the organic surface were considered to predict the stability of the proposed solid layer. Regarding the antibacterial activity, IMCBH was docked against 6KWT target protein aiming to antibacterial effect comparison relating to co-crystalized control. Molecular dynamic simulation was performed to investigate the degree of docked pose stability according to crucial RMSD, RMSF, and H-bonds parameters.

Iron-Catalyzed Oxidative C(sp3)–C(sp3) Radical Coupling Reaction between Thiohydantoins and O-Acetyloximes for the Synthesis of 1,3-Dibenzyl-3,4-dihydropyrrolo[2,3-d]imidazole-2(1H)-thione Derivatives

AbstractA unified heteroannelation method to achieve the synthesis of 1,3-dibenzyl-3,4-dihydropyrrolo[2,3-d]imidazole-2(1H)-thione derivatives with an iron catalyst is proposed. The annelation reaction follows a C(sp3)–C(sp3) radical coupling between a thiohydantoin and an O-acetyloxime. The synthetic approach enables access to several alkynylated thiohydantoins and O-acetyloximes with controlled selectivity toward C(sp3)–C(sp3) coupling rather than C(sp3)–C(sp3)–O coupling in moderate to high yields. An optimization study has been carried out by changing the catalyst loading, oxidants, solvents, and temperature. Synthesized compounds were characterized through 1H and 13C NMR and mass spectral studies.

Photoreactivity of the Non-Steroidal Anti-inflammatory Drug Oxaprozin

Oxaprozin is a phototoxic, non-steroidal anti-inflammatory drug (NSAID) which is generally used in the treatment of inflammation, swelling, stiffness, and joint pain associated with osteoarthritis and rheumatoid arthritis. In addition to these beneficial properties some adverse phototoxic effects are also associated with this drug. For this reason here in we have investigate the photochemical behavior of selected phototoxic drug Oxaprozin. In the present study the methanolic solution of Oxaprozin was irradiated with UVA light under different experimental conditions such as aerobic and anaerobic conditions. The reaction progress was strictly monitored by using thin layer chromatography which confirms the formation of three photoproducts. The isolation of the photoproduct was done by column chromatography. The structural morphology of the isolated photoproducts was established by various spectroscopic techniques such as IR, NMR, 13C NMR mass spectroscopy and High Resolution Mass Spectrometry (HRMS). On the basis of structure the photoproducts are identified as 2-(4,5diphenyl oxazol-2-yl) acetaldehyde (2), 2-(4,5diphenyl oxazol-2yl) ethanol (3), 2ethyl-4,5diphenyl Oxazole (4) by spectral studies.

Hydrogen bond complexation of ethanol with chlorobenzene: FTIR studies

ABSTRACT FTIR spectral studies has been carried out on ethanol (EtOH), chlorobenzene (PhCl) and their binary solutions at various EtOH/PhCl mole fractions. The bonded O − H stretching region has been deconvoluted into four Gaussian peaks centring at 3543.6, 3489.4, 3406.3 and 3254.3 cm−1. The first and the last peaks have been assigned to the hydroxyl stretching bands of dimer and tetramer, while the remaining two to the trimer bands. The presence of dimer in liquid PhCl has been confirmed by the experimental C − Cl stretching bands. Experimentally, two C − Cl stretching bands have been observed, which fall outside the 1096–1089 cm−1 range reported for chlorobenzenes in literature. The positional changes in O − H , C H 3 , C H 2 , C − H and C − Cl stretching bands in the spectrum of the solutions have been analysed in terms of heteromolecular H-bond interactions. This analysis shows that the classical O − H ⋯ Cl hydrogen bonds are the dominant interaction forces.

Severe perturbation and observation of forbidden transitions in asymmetrically deuterated methanol (CHD2OH) and atlas of very accurate torsional rotational spectrum obtained using Synchrotron radiation

High-resolution spectral studies have been continued for the doubly deuterated methanol species (CHD2OH) in the entire region from far infrared (FIR) to Infrared (IR). The spectrum has been obtained using a conventional Fourier transform spectrometer and the state-of-the-art Synchrotron radiation-based spectrometer with unprecedented resolution and very high signal-to-noise (S/N). During the investigation severe perturbation was encountered. The perturbation has been characterized as due to first and second-order Coriolis interaction. The interaction affected a wide range of states and caused the spectral study quite challenging. The perturbation caused a variety of mixing of states producing hybrid states. This hybridization resulted in producing a large number of transitions which should not be allowed by the dipole selection rules via the “intensity borrowing effect”. It was possible to identify a large number of such forbidden transitions that gain sufficient strength through the “Intensity borrowing” effect. The transitions connecting to these perturbed states have been analyzed using standard Coriolis interaction formulae. The possibility of “Fermi” interaction has been excluded as the interaction is highly dependent on the rotational quantum number J. In general, this kind of transition should be excluded from global analysis and should be treated in isolation. It is pertinent to note that some previously published works studied these states using un-substantiated assignments being perhaps unaware of the perturbation. Corrections have been suggested for the analysis and understanding of the properties of the energy levels which have subtle differences with the energy levels of normal asymmetric molecules. In all, available microwave (MW) millimeter wave (MMW) far infrared (FIR), and infrared (IR) assignments have been put together to prepare the most accurate and and complete atlas of about 12,000 spectral lines. This atlas (Appendix A) should be considered a work-in-progress supplement to this paper and supersedes all other lists known to date on this species can be had from one of us (IM) or via Researchgate.

Fabrication, physicochemical characterization and theoretical studies of some new mixed ligands complexes based on N-(1H-benzimidazol-2-yl)-guanidine and 1, 10-phenanthroline: DNA interaction, biological applications and molecular docking approach

The fabrication and structural identification of mixed ligand chelates resulting from 1-(1H-benzimidazol-2-yl) guanidine (BIG = main ligand) and 1,10-Phenanthroline (phen) (secondary ligand). The tested compounds were investigated using TGA, CHN, spectra analysis (FT-IR, Mass spectra, NMR), melting point, magnetic moments, molar conductance, Ultraviolet–Visible spectroscopy as well computational studies. The conductance results showed that the tested Pd(II), VO(II) and Ag(I) chelates have electrolytes in fresh solutions of DMSO lies in the range 38.12–118.87 Ω−1 cm2 mol−1 except, Cu(II) chelate is a non-electrolyte it is value equal 15.16 Ω−1 cm2 mol−1. FT-IR spectrum displays that the tested main ligand is coordinated with metal ions in a bi-dentate behavior with N, N donor sites of the HN=C and C=N. While the second ligand coordinated with metal ions through its N2 atom in the pyridine ring. Moreover, the obtained analytical data regarding complexation in solution, molar ratio and continuous variation methods suggest 1M: 1 L molar ratio. Also the stability constant of tested complexes was identified in solution state and the formation constants (Kf) were evaluated by applying continuous-variation method. Stability of complexes was arranged by BIGPAg > BIGPVO > BIGPCu > BIGPPPd in agreement with Kf values. The pH profile revealed that the wide range of pH stability of the tested complexes is at pH = 4- 10 in most of them. Magnetic and electronic spectra are applied to deduce the coordinating ability of the tested ligands and the geometric structure of the studied chelates. That data of magnetic susceptibility for ternary mixed chelates are locked to an octahedral geometry for Cu(II) & VO(II) chelates due to the data of (μeff = 1.8 and 1.83 B.M) respectively and Pd(II) and Ag(I) chelates are diamagnetic with square planar and tetrahedral geometry, respectively. The TGA study of these studied complexes displays that the hydrated H2O, acetate, nitrate, and acetylacetonate anions are removed in the first (45°C-180°C) and second degradation steps followed directly by degradation of the studied ligands in the following stages. The thermodynamic factors, like ΔS*, ΔH*, E*, A and ΔG* are evaluated from the TGA curves and explained. The DFT/B3LYP computation method was applied for the estimation of the MEP, (HUMO & LUMO) energy for the studied compounds. In-silico assay was executed by two different approaches over compounds to evaluate their biological behavior and degree of interaction with biological systems, before practical application. BIGPPd complex displayed priority in interaction with various protein. In-vitro assay was then carried out for compounds against different microbes and BIGPPd showed high antimicrobial activity with inhibition zones are established to be 45.75 ± 0.10 and 41.95 ± 0.05 mm against B. Cereus and G. Candidum at 25 µg/mL. Also, their cytotoxic behavior was examined against MCF-7, HepG2 and HCT-116 carcinoma cell lines, high cytotoxicity was clearly recorded with BIGPPd complex with IC50% are established to be (5, 6.25 and 7.14 µg/mL) respectively. Furthermore, antioxidant activity was examined, and the complexes exhibited high reactivity with trapping free radicals. The BIGPPd exhibited significant free radical scavenging activity with an IC50 value of 20.15 μg/ml. The interaction of metal chelates with DNA was detected by gel electrophoreses, viscosity and spectral studies. Spectrophotometric titration and viscosity studies expose that each of tested complex is an avid binder to DNA. The intrinsic binding constants were calculated for all the tested compounds could bind to Ct-DNA generally through replacement, intercalative mode & minor groove binding of interactions with the sequence: BIGPVO (6.05×104) > BIGPCu > BIGPPd> BIGPAg >BIG (1.16×103). This may be due to enhanced hydrophobic & electrostatic interaction of aromatic rings. Finally, such complexes may be considered as a promising bioactive agent.

Dual-Channel Imine-Amine Photoisomerization in a Benzoimidazole and Benzothiazole Coupled System: Photophysics and Applications.

A molecule, namely 2-(1H-benzo[d]imidazol-2-yl)-6-(benzo[d]thiazol-2-yl)-4-bromophenol (BIBTB), having a two-way proton transfer unit of thiazole and imidazole moieties was synthesized and characterized by NMR, electrospray ionization mass spectrometry (ESI-MS), and single-crystal diffraction studies. Steady state and time-resolved spectral studies of BIBTB support excited state intramolecular proton transfer (ESIPT), causing imine-amine tautomerization through a two-way 6-membered H-bonded ring, where the N atoms of benzothiazole and the benzoimidazole unit are involved as proton acceptor sites. Interestingly, in a nonpolar and moderately polar solvent, photoisomerization in BIBTB is found to be favored toward the thiazole ring, whereas in a highly polar solvent, it is favored toward the imidazole ring. A spectral comparison of BIBTB with judicially designed molecules 2-(benzo[d]thiazol-2-yl)-4-bromophenol (HBT) and 2-(1H-benzo[d]imidazol-2-yl)-4-bromophenol (BIB) supports these inferences. Theoretical calculation using the Density Functional Theory (DFT) at CAM-B3LYP/6-311+G(d,p) level supports the existence of two low-energy 6-membered hydrogen-bonded planar conformers in the ground state in the gas phase and in solvents of different dielectrics. The potential energy curves (PECs) calculated along the proton transfer (PT) coordinate are found to have a high energy barrier in the ground state and to be barrierless or have a low energy barrier in the excited state for both the forms. The calculated vertical excitation and the emission energy from the relaxed excited and PT states show good correlation with the experimental spectral data. Aggregation of BIBTB in water with red shifted emission was established from X-ray single-crystal structure analysis, solid state emission, and Dynamic Light Scattering (DLS) measurement. The molecule BIBTB also acts as a fluorescence probe for sensing the explosive picric acid in the subnano scale and can be used to determine the proportion of water in dimethyl sulfoxide (DMSO) solvent.

Evaluation of antimicrobial activity and bioactive compound analysis of Verbascum thapsus L. A folklore medicinal plant

BackgroundThe prevalence of microbial infectious diseases is a major contributor to morbidity and mortality on a global scale due to the emergence of antibiotic-resistant microbes, despite the fact that many new antibiotics have been introduced for several decades. In present scenario, the potential utilization of natural plant derived extracts for medicinal and therapeutic purposes has increased remarkably due to adverse effects of synthetic drugs and resistance among pathogenic microbes. Aim of the studyVerbascum thapsus L. (Common mullein) has been traditionally used as a medicine for lung, skin and throat and many other disorders since time immemorial, therefore, the current study was aimed to evaluate the antimicrobial activity of leaf and root extracts of Verbascum thapsus against pathogenic bacterial and fungal strains and its phytochemical composition by spectral studies. MethodsSoxhlet extraction method was employed for extraction process by using varying polarity solvents like hexane, ethyl acetate and methanol. Phytochemical analysis of methanol extract was determined by Fourier Transform-Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC–MS). Antimicrobial activity was evaluated by determining the MIC and MBC/MFC of each extract by broth dilution method. ResultsThe antimicrobial competence of each extract sample was evaluated against six pathogenic bacterial strains and three fungal strains. Methanolic extract of leaves and the ethyl acetate extract of roots of Verbascum thapsus exhibited significant zones of inhibition against all the tested microorganisms. The highest inhibition zone was observed against the bacterial strain Bacillus subtilis (24.1±0.18 mm) followed by Streptococcus pyogenes (22.9±0.64 mm) and the fungal strain Aspergillus niger (22.8±0.55 mm) at a concentration of 500 μg/ml. Methanolic leaf extract strongly inhibited the growth of tested microbial strains with MIC ranged from 15.625 to 125 μg/ml. The FTIR and GCMS analysis confirms the presence of bioactive compound, possessing broad range of therapeutic activities. ConclusionThis Presence of various important phytoconstituents and broad-spectrum antimicrobial activity points Verbascum thapsus as a promising source for the isolations of molecules responsible for antimicrobial activities.

High‐potent trifunctional polybenzoxazines coatings for superhydrophobic cotton fabrics and mild steel corrosion protection applications

AbstractNew trifunctional polybenzoxazines were developed and utilized as a high‐potent coating material for superhydrophobic cotton fabrics and mild steel corrosion protection applications. New trifunctional benzoxazines resin have been synthesized using trihydroxytriphenylmethane (TTM) with dimethylaminopropylamine (dmapa), 1‐(3‐aminopropyl)imidazole (ipa) and aminoethoxyethanol (aee) as amine sources with paraformaldehyde through Mannich condensation. The structural confirmation of synthesized benzoxazines was ascertained by spectral studies. The ring opening polymerization of TTM‐Bzs was studied using DSC analysis. All the three TTM‐Bz monomers show curing temperature lower than 210°C. The thermo‐stability and water contact angle (WCA) of polybenzoxazines were studied using thermogravimetric analysis and goniometer, respectively. Among the TTM‐PBz studied, the poly(dmapa) exhibit better thermo‐stability and hydrophobic behavior when compared to rest of the synthesized polybenzoxazines. Poly(TTM‐dmapa)‐coated cotton fabric exhibits the superhydrophobic behavior and mild steel (MS)‐coated specimen possesses the higher charge transfer resistance value of 3.47 × 107 Ω cm2. It was also inferred that all the TTM‐PBz‐coated MS specimens exhibit higher corrosion protection behavior as well as good thermo‐stability and hydrophobic nature. Further, the obtained results suggested that these materials can be suitably exploited for hydrophobic anticorrosion applications with improved performance and enhanced longevity.