2231-57-4Relevant academic research and scientific papers
Rare-earth (Eu3+, Tb3+) hybrids through amide bridge: Chemically bonded self-assembly and photophysical properties
Liu, Jinliang,Yan, Bing
, p. 580 - 587 (2010)
This work focuses on the construction of a series of chemically bonded rare-earth/inorganic/organic hybrid materials (TCH-Si-Ln, TCH-Si-Ln-Phen and TCH-Si-Ln-Bipy: Phen = 1,10-phenanthroline, Bipy = 2,2′-bipyridyl) using TCH-Si as an organic bridge molecule that can both coordinate to rare-earth ions (Eu3+ and Tb3+) and form an inorganic Si-O-Si network with tetraethoxysilane (TEOS) after cohydrolysis and copolycondensation through a sol-gel process. All of these hybrid materials exhibit homogeneous microstructures and morphologies, suggesting the occurrence of self-assembly of the inorganic network and organic chain. Measurements of the photoluminescent properties of these materials show that the ternary europium systems present stronger luminescent intensities than the binary hybrids, indicating that the introduction of the second ligands can sensitize the luminescence emission of the europium hybrid systems. However, in the terbium systems, this phenomenon was not observed.
Rapid, synergistic extractive spectrophotometric determination of copper(II) by using sensitive chromogenic reagent N″,N?-bis[(E)-(4-fluorophenyl) methylidene]thiocarbonohydrazide
Nalawade, Rekha A.,Nalawade, Avinash M.,Kamble, Ganesh S.,Anuse, Mansing A.
, p. 297 - 306 (2015)
Abstract A rapid and simple spectrophotometric method was developed for the determination of copper(II) by using newly synthesized chromogenic reagent, N″,N?-bis[(E)-(4-fluorophenyl)methylidene]thiocarbonohydrazide [bis(4-fluoroPM)TCH]. The reagent is highly sensitive and it forms yellow colored ternary complex with copper(II) in presence pyridine having composition 1:1:2 (M:L:Py) in the acidic pH range. Absorption of colored complex in amyl acetate is measured with reagent as a blank at kmax 375 nm. The synergistic effect is observed due to pyridine forming adduct with reagent in the organic phase. Beer's law was obeyed in the concentration range from 2.0 to 14 μg mL-1 for copper(II)-[bis(4-fluoroPM)TCH]-Py complex. Molar absorptivity and Sandell's sensitivity values for Cu(II)-bis(4-fluoroPM)TCH]-Py complex are 0.42545 × 105 and 0.0014 μg/cm2, respectively. The selectivity of the developed method was checked in the presence of various foreign ions. The developed method showed relative standard deviation (R.S.D.) of 0.13% for n = 10. The composition of Cu(II)-[bis(4-fluoroPM)TCH]-Py complex was determined by known methods such as Job's method of continuous variation, mole ratio method and slope ratio method. It is found that the ternary complex is stable for more than 24 h. Various factors influencing on the degree of complexation, such as, effect of pH, reagent concentration, synergent concentration, solvent etc. were studied. The accuracy and reliability of method was verified by AAS. This method is found to be simple, rapid and reproducible.
Three-input-three-output logic operations based on absorption and fluorescence dual-mode from a thiourea compound
Wang, Lianlian,Li, Bin,Zhang, Liming,Luo, Yongshi
, p. 459 - 465 (2013)
A simple organic molecule of 2-naphthol-1-aldehyde-conjugated thiourea (denoted as receptor 1) is designed and prepared. Absorption and fluorescence spectra response profiles of receptor 1 with different ionic inputs vary significantly in a DMSO-H2O solution (V/V = 9 : 1) through modulating intramolecular charge transfer (ICT) processes. In particular, the changes of the dual-modal spectra when anions, such as F-, AcO- or H2PO4-, are introduced in such an aqueous solution indicate that receptor 1 could be tolerant to H2O at least to some extent in recognizing anions. On the basis of the above results, binary logic operations (OR, NOR and INHIBIT) and their multiply-logic functions with different combinations have been achieved at the molecular level by changing different chemical inputs. The output signals can be encoded as absorption and fluorescence dual-mode, depending on the choice of 2-naphthol as the chromophore and fluorophore core.
Polynuclear transition metal complexes with thiocarbohydrazide and dithiocarbamates
Siddiqi,Khan, Sadaf,Nami, Shahab A.A.,El-ajaily
, p. 995 - 1002 (2007)
Sn(tch)2{MCl2}2 was prepared from the precursor Sn(tch)2 and MCl2. It was subsequently allowed to react with diethyldithiocarbamate which yielded the trinuclear complexes of the type Sn(tch)2{M2(dtc)4}, where tch = thiocarbohydrazide, M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and dtc = diethyldithiocarbamate. They were characterized on the basis of microanalytical, thermal (TGA/DSC), spectral (IR, UV-vis, EPR, 1H NMR) studies, conductivity measurement and magnetic moment data. On the basis of spectral data a tetrahedral geometry has been proposed for the halide complexes, Sn(tch)2{MCl2}2 except for Cu(II) which exhibits a square planar coordination although the transition metal ion in Sn(tch)2{M2(dtc)4} achieves an octahedral geometry where the dithiocarbamato moiety acts as a symmetrical bidentate ligand. The bidentate nature has been established by the appearance of a sharp single ν(C-S) around 1000 cm-1. A downfield shift observed in NHa and NHb protons on moving from Sn(tch)2 to Sn(tch)2{MCl2}2 is due to the drift of electrons toward metal atoms. A two-step pyrolysis has been observed in the Sn(tch)2{MCl2}2 complexes while their dithiocarbamato derivatives exhibit a three-stage degradation pattern. Finally, the in vitro antibacterial activity of Sn(tch)2{M2(dtc)4} and the mononuclear Sn(tch)2 has been carried out on bacterial strains Escherichia coli and Salmonella typhi. The compounds were found to be active against the test organisms. The activity of the complexes is enhanced with increasing concentration. The maximum activity in both the strains was achieved by cobalt(II) dithiocarbamate complex. Minimum activity was found for Sn(tch)2 which generally increases with the introduction of transition metal ion in the complex.
Design, synthesis and docking studies of a novel ciprofloxacin analogue as an antimicrobial agent
Jubie,Kalirajan,Yadav, Pavankumar
, p. 980 - 987 (2012)
The carboxylic acid group of ciprofloxacin was modified and amino mercapto triazole was substituted. The compound was confirmed by physical parameters (solubility, melting point), chromatographic methods (TLC) and consistent with its IR & 1HNMR spectra. The synthesized analogue was screened for antibacterial activity against one gram positive & two gram negative species. The compound exhibited good antibacterial effect towards gram negative species when compared to the standard ciprofloxacin. At the same time the analogue was retaining antibacterial activity towards gram positive species when compared to standard ciprofloxacin. The molecular docking studies showed a good correlation between their antibacterial activity and autodock binding free energy.
Novel transition metal complexes of 4-hydroxy-coumarin-3- thiocarbohydrazone: Pharmacodynamic of Co(III) on rats and antimicrobial activity
Mosa,Emara, Adel A.A.,Yousef,Saddiq
, p. 35 - 43 (2011)
A new series of stable transition metal complexes of the formula M(L)X·S, where M = Cu(II), Ni(II), Co(III), Cr(III) and Fe(III) and L is the deprotonated ligand of 4-hydroxy-coumarin-3-thiocarbohydrazone, X = Cl -, NO3- or CH3COO- and S = H2O and/or EtOH. The HL ligand was prepared by the reaction of 3-formyl-4-hydroxy-coumarine with thiocarbohydrazide in the molar ratio 1:1. The HL ligand and its metal complexes were characterized by elemental analysis, 1H NMR, IR and electronic spectra, and molar conductance and magnetic measurements and thermal gravimetric analysis (TGA). The HL ligand acts as a monobasic tridentate ONS donor in all metal complexes, and coordinated through the phenolic OH, azomethine nitrogen and thione sulfur. Electronic spectra with magnetic moments suggested varieties of geometries around the central metal atoms. Thermal gravimetric analysis indicates that the complexes are stable up to 300 °C, and release the uncoordinated and/or coordinated H 2O/solvent molecules, which is accompanied by a color change. The formed complexes after releasing the solvent were investigated and their structures are suggested to have square planar or octahedral arrangement. Pharmacodynamic of cobalt(III) complex on some biochemical parameters and histological studies in serum and heart tissue in rats have been studied. Although the complexes demonstrated a significant effect at low dose than the high dose, the ligand showed significant good effects in both high and low doses on the biochemical analysis in serum and heart tissue. Cobalt complex was screened in order to evaluate its antifungal activity against the filamentous fungi Aspergillus niger, Aspergillus fumigatus, and Aspergillus flavus, and antibacterial activity against the Candida albicans, Escherichia coli, Klebseilla pneumoniae and Pseudomonas aeruginosa.
4-amino-1,2,4-triazole-3-thione as a promising scaffold for the inhibition of serine and metallo-β-lactamases
Linciano, Pasquale,Gianquinto, Eleonora,Montanari, Martina,Maso, Lorenzo,Bellio, Pierangelo,Cebrián-Sastre, Esmeralda,Celenza, Giuseppe,Blázquez, Jesús,Cendron, Laura,Spyrakis, Francesca,Tondi, Donatella
, (2020)
The emergence of bacteria that co-express serine-and metallo-carbapenemases is a threat to the efficacy of the available β-lactam antibiotic armamentarium. The 4-amino-1,2,4-triazole-3-thione scaffold has been selected as the starting chemical moiety in the design of a small library of β-Lactamase inhibitors (BLIs) with extended activity profiles. The synthesised compounds have been validated in vitro against class A serine β?Lactamase (SBLs) KPC-2 and class B1 metallo β?Lactamases (MBLs) VIM-1 and IMP-1. Of the synthesised derivatives, four compounds showed cross-class micromolar inhibition potency and therefore underwent in silico analyses to elucidate their binding mode within the catalytic pockets of serine-and metallo-BLs. Moreover, several members of the synthesised library have been evaluated, in combination with meropenem (MEM), against clinical strains that overexpress BLs for their ability to synergise carbapenems.
Design, synthesis and biological evaluation of pleuromutilin-Schiff base hybrids as potent anti-MRSA agents in vitro and in vivo
Li, Bo,Zhang, Zhe,Zhang, Jian-Feng,Liu, Jie,Zuo, Xiang-Yi,Chen, Fang,Zhang, Guang-Yu,Fang, Han-Qing,Jin, Zhen,Tang, You-Zhi
, (2021/06/22)
A series of pleuromutilin derivatives with 1,2,4-triazole-3-substituted Schiff base structure were designed and synthesized under mild conditions. The in vitro antibacterial activities of the synthesized derivatives against 4 strains of Staphylococcus aureus (MRSA ATCC 43300, S.aureus ATCC 29213, S.aureus 144 and S.aureus AD3) and 1 strain of E. coli (ATCC 25922) were evaluated by the broth dilution method. Among these derivatives, compound 60 exhibited superior in vitro antibacterial effect against MRSA (MIC = 0.25 μg/mL) than tiamulin (MIC = 0.5 μg/mL), and compound 60 (?2.28 log10 CFU/mL) also displayed superior in vivo antibacterial efficacy than tiamulin (?1.40 log10 CFU/mL) in reducing MRSA load in the mouse thigh infection model. The time-kill study and the post-antibiotic effect study indicated that compound 60 showed a faster bactericidal kinetic and longer PAE time (exposure to 2 × MIC and 4 × MIC for 2 h, the PAE was 4.06 and 4.27 h) against MRSA compared with tiamulin (exposure to 2 × MIC and 4 × MIC for 2 h, the PAE was 1.72 and 2.14 h). Meanwhile, most of these compounds had no significant inhibitory effect on RAW 264.7 cells and HepG2 cells at the concentration of 4 μg/mL. Additionally, the development of resistance study showed that MRSA did not easily develop resistance against compound 60 compared with tiamulin after induction for 8 passages.
Multi metal ion recognizing unsymmetrical tetra dentate schiff bases associated with antifungal activity
Dhasarathan, Saranya,Kaliappan, Ilango,Selvaraj, Kamatchi P.,Shunmugaperumal, Selvaraj
, p. 833 - 846 (2021/09/08)
New unsymmetrical Schiff bases containing azomethine moiety with simple aromatic section in one side and ferrocene fragment attached imine on the other side have been synthesized. Advent of metal-to-ligand charge transfer band for the coordination of Cu2+ ions with receptors and appropriate changes in UV-Visible spectra for other metal ion combination with the sensor is reported. Observed extravagant ΔEp values suggest quasi-reversible process. The ΔIpa amount calculated from the anodic current Ipa value noticed for receptor solution and different metal ion added sensor solution discloses the concentration of metal ions required for effective sensing. The synthesized ligands were subjected to antimicrobial activity against four bacterial and two fungal stains and the zone of inhibition (in mm) was calculated. Further molecular docking study was carried out and the binding energy (Kcal.mol-1) for the synthesized ligand (R1 and R2) with the selected protein was intended.
Pleuromutilin derivative with 1,2,4-triazole Schiff base as well as preparation and application of pleuromutilin derivative
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Paragraph 0102-0103, (2020/10/04)
The invention belongs to the field of medicinal chemistry, and particularly relates to a pleuromutilin derivative with 1,2,4-triazole Schiff base as well as preparation and application of the pleuromutilin derivative. The pleuromutilin derivative with 1,2,4-triazole Schiff base is a compound represented by a formula 2 or a pharmaceutically acceptable salt thereof, and a solvate, an enantiomer, a diastereoisomer, a tautomer or a mixture of the solvate, the enantiomer, the diastereoisomer and the tautomer of the compound of formula 2 or the pharmaceutically acceptable salt thereof, the compoundnot only has good in-vitro antibacterial activity, but also has the advantage of low preparation cost compared with valnemulin and retapamulin, so that the compound is particularly suitable for beingused as a novel antibacterial drug for preventing and treating human or animal bacterial infectious diseases, particularly infectious diseases caused by drug-resistant staphylococcus aureus.
