Temperature dependent magnetoelectric studies are performed for 0.37 BiScO3-0.63 PbTiO3-NiFe2O4 laminate composites in the temperature range of 25 °C–200 °C. The co-fired laminates are sintered at ...two different temperatures, 1100 °C and 1200 °C, closer to the sintering temperature of the ferroelectric and ferrite phases. The effect of sintering temperature on co-fired laminates is investigated by analyzing the structural, morphology, ferroelectric properties along with the direct and converse magnetoelectric coefficients. With increase in sintering temperature, the magnetoelectric coupling coefficient of the co-fired laminate is found to increase. The direct magnetoelectric coefficient of co-fired laminate, sintered at 1200 °C, is found to be comparable to that of the epoxy bonded laminate. Finally, the temperature dependent direct magnetoelectric studies are carried out in co-fired laminates and the results are compared with that of epoxy bonded laminate. The magnetoelectric interaction in epoxy bonded laminate, strongly affected by temperature, can be ascribed to softening of the epoxy layer. The co-fired laminate, which has no epoxy layer, exhibits a better thermal stability in terms of stable magnetoelectric coefficient up to 200 °C making it a suitable candidate for high temperature magnetic field sensors.
•Direct and converse magnetoelectric studies are performed in co-fired composites.•Sintering conditions improves magnetoelectric coupling in co-fired laminates.•Co-fired samples shows better thermal stability than epoxy bonded laminates.•Softening of epoxy with temperature decreases magnetoelectric coupling.
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•Design and synthesis of Quinolinyl dihydropyridine carboxylates (QDC) derivatives.•QDC derivatives incorporate the antibacterial activity of quinolines with drug resistance reversal ...effect of 1,4 DHP’s.•The QDC derivatives were characterized by NMR, FT-IR, Mass and CHN analysis.•The QDC derivatives were screened for antibacterial activity, MIC and cytotoxicity.•Molecular docking studies of QDC diastereomers with bacterial cell wall were studied.•The mode of antibacterial action of QDC derivatives were evaluated via SEM analysis.•All the QDC derivatives exhibited antibacterial activity against vibrio cholera.
Novel pyranoquinolinyl dihydropyridine carboxylate (PDC) derivatives were designed by incorporating the multi-drug resistance modulating effects of 1,4 dihydropyridines along with potential antibacterial activity of quinolines in the molecular design. The designed PDC derivatives were synthesized by multi-step synthesis involving Michael addition, reduction followed by inverse electro demand Diels-Alder reaction to produce pyranoquinolinyl dihydropyridine carboxylates in good yields. All the PDC derivatives were characterized by 1H NMR, 13C NMR, FT-IR, Mass spectral and CHN analysis. The Quinolinyl dihydropyridine carboxylate derivatives were evaluated for in vitro antibacterial activity by agar well diffusion method. Molecular docking studies revealed that the exo diethyl 4-(4aR,5S,10bR)-5-(4-chlorophenyl)-3,4,4a,5,6,10b-hexahydro-2H-pyrano3,2-cquinolin-8-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate diastereomer (5c) forms four hydrogen bonds with the cell wall protein of vibrio cholerae in comparison to the endo diethyl 4-((4aR,5R,10bR)-5-(4-chlorophenyl)-3,4,4a,5,6,10b-hexahydro-2H-pyrano3,2-cquinolin-8-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate diastereomer (4c) which forms two hydrogen bonds with the cell wall protein of vibrio cholerae and hence leading to better anchorage, enhanced gold score and relatively good antibacterial activity for the exo PDC derivatives. Minimum inhibitory concentration (MIC) of the active compounds was evaluated by macro dilution method. The mechanism of antibacterial action of the PDC derivatives was investigated by SEM studies. The cytotoxicity of PDC derivatives were evaluated against fibroblast cells (L-929).
Zeokarb-225, is a heterogenous, recyclable, eco-benign catalyst for the liquid phase electrophilic substitution reactions of indoles with aldehydes or indole aldehydes to afford the corresponding ...bis(indolyl)methanes or tris(indolyl)methanes in good yields. The catalyst is also effective for the synthesis of new diindolylcarbazolylmethanes in good yields. The catalyst was characterized by FT-IR and in situ DRIFT studies (pyridine adsorption). All the products were extensively characterized by NMR, FT-IR, GC-MS and CHN analyses. A mechanism for the catalytic activity is proposed. The catalyst can be recovered and reused without loss of activity. The work-up of the reaction consists of a simple filtration, followed by concentration of the crude product and purification. The effect of solvent, the effect of substituents, the influence of mole ratio, the effect of stirring speed and the recyclable use of the catalyst are also investigated.
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•The first target specific synthesis of pyranoquinolinyl acrylic acid diastereomers.•Spectral characterisation of the products by NMR, FT-IR, Mass and CHN analysis.•Synthesis of ...biologically active diastereomers by employing Eu(hfc)3 or Eu(tfc)3.•Molecular docking and in vitro α-glucosidase inhibitory studies of products.•Lipinski evaluation and plausible mechanism for the synthesis is proposed.
In the present investigation we report the first target specific, highly diastereoselective synthesis of new class of pyranoquinolinyl/furoquinolinyl-acrylic acid diastereomers and evaluation of their invitro α-glucosidase inhibitory activity. All the products were thoroughly characterized by 1H NMR, 13C NMR, FT-IR, Mass spectral and CHN analysis. A highly diastereoselective target specific route of synthesis for the biologically active diastereomers were developed by usingchiral catalyst Europium tris3-heptafluoropropylhydroxyl methylene-(−)-camphorate (A) or Europiumtris3-(trifluoromethyl)hydroxylmethylene-(+)-camphorate (B). It was found that among a set of 4 diastereomeric products obtained, exodiasteromers of pyranoquinolinyl acrylic acid adducts exhibited relatively high α-glucosidase inhibitory activity. The newly synthesized compounds exhibited IC50 values in the range of (0.40 ± 0.02–30.3 ± 0.84 μM) as compared to standard acarbose (IC50 = 0.65 ± 0.02 μM). It was found that compounds 11a, 11c, 11d and 12d were found to be more active than standard acarbose. It was also found that unsubstituted compound (11a) or compounds with chlorine or methoxy substituent (11c, 11d, 12d) showed potential α-glucosidase inhibitory activity. However a reversal in activity was observed with Nitro substituent (11b, 13b) wherein the endodiastereomers were found to be more active than exodiastereomers. Molecular docking studies were used for design of the compound and understand the mode of binding between the compound and target enzyme. A plausible mechanism for the diastereoselective synthesis was also proposed.
In the present study, we report the design and eco‐benign synthesis of new class of carbazolyl‐1,4‐dihydropyridine (1,4‐CDHP) and carbazolyl‐1,8‐dioxodecahydroacridine (CAD) derivatives via a ...three‐component coupling reaction of substituted carbazole aldehydes, ethyl acetoacetate/dimedone, and ammonium acetate under solvent‐free conditions at 112°C to 115°C. We also report an efficient one‐pot synthesis of new class of carbazolyl polyhydroquinoline (CPQ) derivatives via a four‐component coupling reaction of substituted ethyl acetoacetate, dimedone, ammonium acetate, and carbazole aldehydes in acetonitrile/water medium (3:1) at 73°C to 75°C in moderate yields. All the products were thoroughly characterized by 1H NMR, 13C NMR, Fourier transform infrared (FTIR), mass spectral, and CHN analysis. The synthesized heterocyclic compounds were evaluated for their in vitro antibacterial activity against pathogenic strains of both Gram‐negative and Gram‐positive bacteria. Minimum inhibitory concentration (MIC) of the active compounds was evaluated by macrodilution method. The CPQ derivative (8a) displayed superior antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi with the MIC values of 16.0 to 32.0 μg/mL in comparison with the reference drug. The mechanism of antibacterial action of the CPQ derivatives was investigated via scanning electron microscope (SEM) studies. The molecular docking studies indicate that the CPQ derivative (8a) binds to the cell wall protein of E coli and P aeruginosa by formation of hydrogen bonds with amino acid residues (TYR328 and GLU249) of the bacterial cell wall protein. The 1,4‐CDHP, CAD, and CPQ derivatives were either noncytotoxic or exhibited minimal cytotoxicity towards human mononuclear cells from peripheral blood. All the products were evaluated for Lipinski rule of five (RO5) and were found to have good oral bioavailability.
A new mono(bis(2-(4-butylphenyl)imino)methyl)phenoxy)zinc(II)dichloride (MBPMP) single crystal was grown by slow evaporation technique in ethanol. Single crystal XRD studies confirm that the MBPMP ...crystal is mononuclear, with tetragonal coordination geometry and P4
1
2
1
2 noncentrosymmetric space group. The FT-IR spectral analysis was used for identifying the functional groups and bonding nature present in the MBPMP crystal. The UV–Visible-NIR studies reveals that the MBPMP single crystal exhibits a very broad transparency window in the near infrared and visible regions between 220 to 1200 nm and the optical transparency of the MBPMP crystal is 99.49% with the lower cut-off wavelength of 220 nm. The optical energy band gap evaluated from the transmission spectrum was found to be 5.63 eV. The Vickers microhardness number 1.8544 P/d
2
kg/mm
3
and the work hardening coefficient number (n = 2.326) indicates that the MBPMP single crystal is soft natured. TGA/DSC analysis of the title coordination compound indicated that there is no weight loss up to 209 °C indicating that the grown MBPMP crystal is thermally stable up to 209 °C. MBPMP single crystal exhibits lower dielectric constant and lower dielectric loss at higher frequencies indicating good quality optical crystal. The second harmonic generation efficiency of the MBPMP crystal by using Kurtz’s powder technique employing Q-switched Nd: YAG laser found that the intensity of bright green light emission is 1.2 times greater than that of standard KDP crystal. The laser damage threshold value of the MBPMP single crystal was calculated to be 3.86 GW/cm
2
.
Electrophilic substitution of indoles with carbonyl compounds was carried out over HY, Hβ and H-ZSM-5 zeolites as effective heterogeneous catalysts. These zeolites afford good to excellent yield of ...bis(indolyl)methanes at room temperature. Vibrindole A, a novel beneficial compound, has been successfully synthesised for the first time in the presence of zeolite in good yield. The yield of bis(indolyl)methanes increases in the order H-ZSM-5
<
Hβ
<
HY, which is in accordance with the acid site density of the catalyst. The catalysts can be reused five times without any loss in catalytic activity.
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