scholarly journals Macrocycliczinc(II) Complexes with Tetradentate N2O2 Donor Schiff Base Ligands Incorporating 1,3,4-Thiadiazole Ring

2020 ◽  
Vol 36 (6) ◽  
pp. 1148-1153
Author(s):  
Arti Vishwkarma ◽  
A. K. Srivastava ◽  
Om P. Pandey ◽  
Soumitra K. Sen Gupta
Keyword(s):  
Synthesis Method ◽  
Pathogenic Fungi ◽  
Macrocyclic Ligands ◽  
Water Molecules ◽  
Schiff Base Ligands ◽  
E Coli ◽  
Elemental Analyses ◽  
Thiadiazole Ring ◽  
Template Synthesis Method ◽  
Coordinated Water

A new series ofdiazadioxamacrocycliczinc(II) derivatives [{Zn(M)(H2O)2}(OAc)2] (M= macrocyclic ligands) prepared via template synthesis method, by the reaction of Schiff bases derived from bis-(2-hydrazino-1,3,4-thiadiazole-5-yl)arene/alkanes and 3,5-dichlorosalicyldehyde/2-hydroxy-1-naphthaldehyde with 1,4-dibromobutane in the presence of Zn(II) ion. The structures of all these complexes were established on the basis of elemental analyses, spectral data (IR and 1H-NMR), PXRD, SEM techniques. Presence of coordinated water molecules in the Zn(II) complexes were confirmed by TGA analyses. The antimicrobial effects of all the synthesized complexes were evaluated against different species of pathogenic fungi (A. niger, A. alternata ) and bacteria (E. coli, B. subtilis).

scholarly journals Entropy-driven binding of gut bacterial β-glucuronidase inhibitors ameliorates irinotecan-induced toxicity

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Hsien-Ya Lin ◽  
Chia-Yu Chen ◽  
Ting-Chien Lin ◽  
Lun-Fu Yeh ◽  
Wei-Che Hsieh ◽  
...  
Keyword(s):  
Cancer Metabolism ◽  
Glucuronic Acid ◽  
Intestinal Epithelial Cells ◽  
Primary Treatment ◽  
Water Molecules ◽  
Intestinal Epithelial ◽  
E Coli ◽  
Severe Diarrhea ◽  
Coordinated Water ◽  
Consequent Increase

AbstractIrinotecan inhibits cell proliferation and thus is used for the primary treatment of colorectal cancer. Metabolism of irinotecan involves incorporation of β-glucuronic acid to facilitate excretion. During transit of the glucuronidated product through the gastrointestinal tract, an induced upregulation of gut microbial β-glucuronidase (GUS) activity may cause severe diarrhea and thus force many patients to stop treatment. We herein report the development of uronic isofagomine (UIFG) derivatives that act as general, potent inhibitors of bacterial GUSs, especially those of Escherichia coli and Clostridium perfringens. The best inhibitor, C6-nonyl UIFG, is 23,300-fold more selective for E. coli GUS than for human GUS (Ki = 0.0045 and 105 μM, respectively). Structural evidence indicated that the loss of coordinated water molecules, with the consequent increase in entropy, contributes to the high affinity and selectivity for bacterial GUSs. The inhibitors also effectively reduced irinotecan-induced diarrhea in mice without damaging intestinal epithelial cells.

A Pyrazine-Bridged Ni(II) Coordination Polymer

2002 ◽  
Vol 57 (11) ◽  
pp. 1191-1194 ◽  
Author(s):  
Chirantan Roy Choudhury ◽  
Subrata Kumar Dey ◽  
Sutapa Sen ◽  
Bappaditya Bag ◽  
Samiran Mitra ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Chain Structure ◽  
Water Molecules ◽  
Polymeric Complex ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
Elemental Analyses ◽  
Coordinated Water ◽  
Nitrate Anions

The single pyrazine-bridged polymeric complex {[Ni(pyz)(H2O)4](NO3)2.2H2O}n has been synthesised and characterised by elemental analyses, IR and UV-vis spectra, and a single-crystal X-ray diffraction study. The coordination around the Ni centre is perfectly octahedral. The Ni(H2O)4 coordination planes are bridged by pyrazine ligands forming an infinite chain structure. Two nitrate anions and two water molecules exist in the lattice and are linked by intermolecular hydrogen bonds to the coordinated water molecules.

Solid-state structure and antimicrobial and cytotoxicity studies of a cucurbit[6]uril-like Cu6 L 4 constructed from 3,5-bis[(1H-tetrazol-5-yl)methyl]-4H-1,2,4-triazol-4-amine

2018 ◽  
Vol 74 (11) ◽  
pp. 1413-1419
Author(s):  
Serhii Vasylevskyi ◽  
Anja Holzheu ◽  
Katharina M. Fromm
Keyword(s):  
Solid State ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
State Structure ◽  
Sulfate Anion ◽  
E Coli ◽  
Cytotoxicity Studies ◽  
Distorted Octahedral ◽  
Sulfate Hydrate ◽  
Coordinated Water

3,5-Bis[(1H-tetrazol-5-yl)methyl]-4H-1,2,4-triazol-4-amine (H2 L) associates under deprotonation with CuSO4 in aqueous medium to form a new waisted barrel-shaped M 6 L 4 cluster, namely hexaaquatetrakis{μ4-3,5-bis[(1H-tetrazol-5-yl)methyl]-4H-1,2,4-triazol-4-amine}-μ4-sulfato-hexacopper(II) sulfate hydrate, [Cu6(SO4)(C6H6N12)4(H2O)6]SO4·nH2O (n = ∼23) (1). Cluster 1 resembles concave cucurbit[6]uril and has one disordered sulfate anion trapped inside the cage, which additionally stabilizes the Cu6 unit. The CuII ions have either a square-pyramidal or a distorted octahedral geometry. The equatorial positions are filled by N atoms from the L 2− ligand, while the axial positions are occupied by coordinated water molecules and O atoms of the sulfate counter-ion. In the solid state, the Cu6 clusters are connected through a large number of hydrogen bonds formed by uncoordinated water molecules and an additional sulfate anion. The compound shows good antimicrobial activity against E. coli tested with the Kirby Bauer approach. In addition, the cell viability towards HeLa and L-929 cells was studied.

scholarly journals Synthesis, Structural Investigation and Antimicrobial Properties of Macrocyclic Zinc(II) Complexes with N2O2-Donor Schiff Bases Incorporating 1,2,4-Triazole Ring

2020 ◽  
Vol 32 (12) ◽  
pp. 3151-3156
Keyword(s):  
Schiff Bases ◽  
Structural Investigation ◽  
Thermal Studies ◽  
Antimicrobial Properties ◽  
Triazole Ring ◽  
Pathogenic Fungi ◽  
Elemental Analyses ◽  
Coordinated Water ◽  
In Situ Reactions

A novel series of nano-sized zinc(II) complexes of type [{Zn(M)(H2O)2}(CH3COO–)2] (where M = macrocyclic ligands) has been synthesized by the in situ reactions of Schiff bases derived from 3-(phenyl/substituted phenyl)-4-amino-5-hydrazino-1,2,4-triazoles, salicyldehyde/2-hydroxy-1- naphthaldehyde and 1,4-dibromobutane/1,5-dibromopentane in presence of zinc(II) acetate dihydrate in absolute ethanol. The structures of all these zinc(II) complexes were established on the basis of elemental analyses and spectral data (IR, 1H NMR and 13C NMR). Scanning electron microscopy studies have been carried out to investigate the particle size and surface morphology of a particular complex while thermal studies confirm the presence of coordinated water molecules in all the zinc(II) complexes. The antimicrobial effects of all the synthesized complexes were studied against different species of pathogenic fungi and bacteria.

Synthesis and Properties of a New Bacteriostatic Agent of Ballast Water

2013 ◽  
Vol 726-731 ◽  
pp. 2461-2467 ◽  
Author(s):  
Bai Kang Zhu
Keyword(s):  
Ballast Water ◽  
Cobalt Complex ◽  
Synthesis Method ◽  
Water Molecules ◽  
Monoclinic System ◽  
Cell Parameters ◽  
Distorted Octahedral ◽  
Bacteriostatic Agent ◽  
Coordinated Water ◽  
Better Than

The intrusion of pathogens into ballast water, not only destroys marine ecological environment, but also threatens human health. The study synthesized a new cobalt complex with a ligand of 3-pyridine-4-benzoic acid by hydrothermal synthesis method. Its structure was characterized by elemental analyzer and single crystal diffractometer, and its infrared spectroscopy, thermal stability and inhibitory activity were analyzed. The results show that the complex belongs to the monoclinic system and space group C2 / c, with unit cell parameters a = 8.2484 (9) Å, b = 10.3371 (11) Å, c = 12.2031 (14) Å, α = 89.588 (2) °, β = 87.0870 (10) °, cell volume = 982.03 (19) Å3, Z = 2, F (000) = 508, Dcalc = 1.709mg/cm3, R1 = 0.0391 and wR2 = 0.0807. The asymmetric unit of the complex consists of the two Co ions, four ligand molecules and two coordinated water molecules, each center Co ions forms a hexacoordinated distorted octahedral structure. The MIC of complex for Escherichia coli, Salmonella and Vibrio parahaemolyticus in ballast water are respectively 78μg/mL, 39μg/mL and 78μg/mL, and its antimicrobial effects is better than ligands, which can be used as a novel bacteriostatic agent of ballast water.

A Rare Example of a Dinuclear Cobalt(II) Complex with Dipicolinate and Bridging 2-Aminopyrazine Ligands. Preparation, Structural, Spectroscopic and Thermal Characterization

2011 ◽  
Vol 66 (8) ◽  
pp. 813-818 ◽  
Author(s):  
Masoumeh Tabatabaee ◽  
Boris-Marko Kukovec ◽  
Vajieh Razavimahmoudabadi
Keyword(s):  
Dipicolinic Acid ◽  
3D Structure ◽  
Thermal Characterization ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
Distorted Octahedral ◽  
Elemental Analyses ◽  
Coordinated Water ◽  
Oxygen Atoms

A dinuclear cobalt(II) complex, [Co2(H2O)4(dipic)2(μ-apyz)] (dipicH2 = pyridine-2,6-dicarboxylic (dipicolinic) acid, apyz = 2-aminopyrazine) (1), has been hydrothermally synthesized and characterized by elemental analyses, spectroscopic methods (IR, UV/Vis), thermal analysis as well as by X-ray diffraction studies. The dinuclear complex is composed of two cobalt(II) ions bridged by a 2-aminopyrazine molecule. Each cobalt(II) ion is coordinated by one nitrogen and two oxygen atoms of the tridentate dipicolinate anion, one heterocyclic nitrogen atom of the 2-aminopyrazine and two oxygen atoms of coordinated water molecules. The resulting geometry for the CoN2O4 coordination environment can be described as distorted octahedral. Various hydrogen bonds of the type O-H···O and N-H···O are also present in the crystal structure. This arrangement leads to the formation of a 3D structure.

scholarly journals Crystal structure oftrans-diaqua(3,10-dimethyl-1,3,5,8,10,12-hexaazacyclotetradecane)copper(II) pamoate

2019 ◽  
Vol 75 (5) ◽  
pp. 533-536 ◽  
Author(s):  
Liudmyla V. Tsymbal ◽  
Irina L. Andriichuk ◽  
Vladimir B. Arion ◽  
Yaroslaw D. Lampeka
Keyword(s):  
Bond Length ◽  
Macrocyclic Ligand ◽  
Octahedral Geometry ◽  
Macrocyclic Ligands ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Hydrogen Bonding Interactions ◽  
Pamoic Acid ◽  
Proton Donors ◽  
Coordinated Water

The asymmetric unit of the title compound,trans-diaqua(3,10-dimethyl-1,3,5,8,10,12-hexaazacyclotetradecane-κ4N1,N5,N8,N12)copper(II) 4,4′-methylenebis(3-hydroxynaphthalene-2-carboxylate), [Cu(C10H26N6)(H2O)2](C23H14O6) {[Cu(L)(H2O)2](pam), whereL= 3,10-dimethyl-1,3,5,8,10,12-hexaazacyclotetradecane and pam = dianion of pamoic acid} consists of two independent halves of the [Cu(L)(H2O)2]2+cation and one dicarboxylate anion. The CuIIatoms, lying on inversion centres, are coordinated by the four secondary N atoms of the macrocyclic ligands and the mutuallytransO atoms of the water molecules in a tetragonally elongated octahedral geometry. The average equatorial Cu—N bond length is significantly shorter than the average axial Cu—O bond length [2.007 (10) and 2.486 (18) Å, respectively]. The macrocyclic ligand in the complex cations adopts the most energetically stabletrans-III conformation. The complex cations and anions are connectedviahydrogen-bonding interactions between the N—H groups of the macrocycles and the O—H groups of coordinated water molecules as the proton donors and the O atoms of the carboxylate as the proton acceptors into layers lying parallel to the (1\overline{1}1) plane.

A gadolinium cryptate with two coordinated water molecules

1998 ◽  
pp. 3711-3714 ◽  
Author(s):  
S. W. Annie Bligh ◽  
Michael G. B. Drew ◽  
Noreen Martin ◽  
Beatrice Maubert ◽  
Jane Nelson
Keyword(s):  
Water Molecules ◽  
Coordinated Water

scholarly journals Enhanced Extracellular Synthesis of Gold Nanoparticles by Soluble Extracts from Escherichia coli Transformed with Rhizobium tropici Phytochelatin Synthase Gene

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 472
Author(s):  
Qunying Yuan ◽  
Manjula Bomma ◽  
Zhigang Xiao
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Synthesis Method ◽  
Nanoparticle Synthesis ◽  
Morphological Properties ◽  
Phytochelatin Synthase ◽  
Rhizobium Tropici ◽  
Whole Cells ◽  
E Coli ◽  
Recombinant Cells

Phytochelatins, the enzymatic products of phytochelatin synthase, play a principal role in protecting the plants from heavy metal and metalloid toxicity due to their ability to scavenge metal ions. In the present study, we investigated the capacity of soluble intracellular extracts from E. coli cells expressing R. tropici phytochelatin synthase to synthesize gold nanoparticle. We discovered that the reaction mediated by soluble extracts from the recombinant E. coli cells had a higher yield of gold nanoparticles, compared to that from the control cells. The compositional and morphological properties of the gold nanoparticles synthesized by the intracellular extracts from recombinant cells and control cells were similar. In addition, this extracellular nanoparticle synthesis method produced purer gold nanoparticles, avoiding the isolation of nanoparticles from cellular debris when whole cells are used to synthesize nanoparticles. Our results suggested that phytochelatins can improve the efficiency of gold nanoparticle synthesis mediated by bacterial soluble intracellular extracts, and the potential of extracellular nanoparticle synthesis platform for the production of nanoparticles in large quantity and pure form is worth further investigation.

scholarly journals Crystal structure of poly[diaquabis(μ5-benzene-1,3-dicarboxylato)(N,N-dimethylformamide)cadmium(II)disodium(I)]

2017 ◽  
Vol 73 (11) ◽  
pp. 1599-1602 ◽  
Author(s):  
Matimon Sangsawang ◽  
Kittipong Chainok ◽  
Nanthawat Wannarit
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Carboxylate Groups ◽  
Benzene Rings ◽  
Coordinated Water ◽  
Coordinate Geometry

The title compound, [CdNa2(C8H4O4)2(C3H7NO)(H2O)2]nor [CdNa2(1,3-bdc)2(DMF)(H2O)2]n, is a new CdII–NaIheterobimetallic coordination polymer. The asymmetric unit consists of one CdIIatom, two NaIatoms, two 1,3-bdc ligands, two coordinated water molecules and one coordinated DMF molecule. The CdIIatom exhibits a seven-coordinate geometry, while the NaIatoms can be considered to be pentacoordinate. The metal ions and their symmetry-related equivalents are connectedviachelating–bridging carboxylate groups of the 1,3-bdc ligands to generate a three-dimensional framework. In the crystal, there are classical O—H...O hydrogen bonds involving the coordinated water molecules and the 1,3-bdc carboxylate groups and π–π stacking between the benzene rings of the 1,3-bdc ligands present within the frameworks.

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