scholarly journals Synthesis and characterisation of bismacrocyclic DO3A-amide derivatives – an approach towards metal-responsive PARACEST agents

2016 ◽  
Vol 45 (15) ◽  
pp. 6555-6565 ◽  
Author(s):  
Nevenka Cakić ◽  
Tatjana Ž. Verbić ◽  
Ratomir M. Jelić ◽  
Carlos Platas-Iglesias ◽  
Goran Angelovski
Keyword(s):  
Lanthanide Complexes ◽  
Zinc Ions ◽  
Amide Derivatives ◽  
Calcium Magnesium

Three bismacrocyclic amide derivatives bearing two types of chelating moieties were prepared. The properties of their lanthanide complexes in the absence and presence of calcium, magnesium or zinc ions were studied.

scholarly journals Lanthanide complexes of DOTA-nitroxide conjugates for redox imaging: Spectro-electrochemistry, CEST, relaxivity, and cytotoxicity.

2021 ◽  
Author(s):  
Damien Mouchel dit Leguerrier ◽  
Richard Barre ◽  
Quentin Ruet ◽  
Daniel Imbert ◽  
Christian Philouze ◽  
...  
Keyword(s):  
Lanthanide Complexes ◽  
Redox Active ◽  
Amide Derivatives ◽  
L1 And L2

The lanthanide(III) complexes (Gd, Eu, Dy, Yb) of DOTA tris(amide) and bis(amide) derivatives (L1 and L2) featuring one redox active TEMPO arm were prepared. Ligand L2 harbours an alkyne fragment...

scholarly journals Biosynthesis and Degradation of H2O2 by Vaginal Lactobacilli

2009 ◽  
Vol 76 (2) ◽  
pp. 400-405 ◽  
Author(s):  
Rebeca Martín ◽  
Juan E. Suárez
Keyword(s):  
Defense Mechanisms ◽  
Antimicrobial Effect ◽  
Zinc Ions ◽  
Hydrogen Peroxide Production ◽  
Vaginal Colonization ◽  
Vaginal Lactobacilli ◽  
Lactobacillus Jensenii ◽  
Calcium Magnesium ◽  
Tetramethyl Benzidine ◽  
Model Strain

ABSTRACT Hydrogen peroxide production by vaginal lactobacilli represents one of the most important defense mechanisms against vaginal colonization by undesirable microorganisms. To quantify the ability of a collection of 45 vaginal Lactobacillus strains to generate H2O2, we first compared three published colorimetric methods. It was found that the use of DA-64 as a substrate rendered the highest sensitivity, while tetramethyl-benzidine (TMB) maintained its linearity from nanomolar to millimolar H2O2 concentrations. Generation of H2O2 was found to be especially common and strong for L. jensenii strains, while it was variable among L. crispatus and L. gasseri strains. Biosynthesis of H2O2 only occurred upon agitation of the cultures, but the H2O2-producing machinery was already present in them before aeration started. Calcium, magnesium, manganese, and zinc ions did not affect H2O2 production, while Cu2+ inhibited the growth of Lactobacillus jensenii CECT 4306, which was chosen as a model strain. Cultures with Fe3+, hemin, and hemoglobin did not accumulate H2O2. Fe3+ activated an extracellular peroxidase that destroyed the H2O2 being produced by the cultures. This protected the lactobacilli against its antimicrobial effect. The production of the enzyme appears to be constitutive, the Fe3+ ions being a necessary cofactor of the reaction.

Effects of certain cations on the formation and infectivity of Phytophthora zoospores. 2. Effects of copper, boron, cobalt, manganese, molybdenum, and zinc ions

1977 ◽  
Vol 23 (8) ◽  
pp. 1002-1010 ◽  
Author(s):  
D. M. Halsall
Keyword(s):  
Mycelial Growth ◽  
Copper Ions ◽  
Protective Action ◽  
Fungal Species ◽  
Zinc Ions ◽  
Dilute Solution ◽  
Infection Period ◽  
Total Inhibition ◽  
Pot Trials ◽  
Calcium Magnesium

The effects of copper, boron, cobalt, manganese, molybdenum, and zinc on the production of zoosporangia by P. cinnamomi and P. drechsleri in the presence of favourable concentrations of calcium, magnesium, potassium, and iron were investigated. Copper ions were the most effective in reducing the numbers of zoosporangia formed by both fungal species. Molybdenum was also slightly inhibitory.Total inhibition of mycelial growth occurred between 1 and 5 × 10−5 M Cu2+ whereas total inhibition of sporangial formation occurred between 1 and5 × 10−7 M Cu2+. At copper concentrations between 10−5 M and 5 × 10−7 M, many P. drechsleri zoosporangia were abnormal in appearance and nonviable.Infection of eucalypt cotyledons by P. drechsleri zoospores was inhibited by 10−6 M Cu2+ but this inhibition was reversed by EDTA (10−4 M). There was no evidence for interaction between Cu2+ and Ca2+, Mg2+, K+, or Fe2+ present in the solutions used in the axenic production of zoospores. Preliminary pot trials indicated that CuSO4 had a protective action for safflower seedlings to infection by P. drechsleri when CuSO4 was applied as a dilute solution over the infection period.

A Highly Selective Luminescent Sensor for Detecting Mercuric Ions in Water

2009 ◽  
Vol 62 (12) ◽  
pp. 1593 ◽  
Author(s):  
Sofian M. Kanan ◽  
Imad A. Abu-Yousef ◽  
Nora Hassouneh ◽  
Ahmed Malkawi ◽  
Naser Abdo ◽  
...  
Keyword(s):  
Linear Response ◽  
Limit Of Detection ◽  
Environmental Water ◽  
Zinc Ions ◽  
Ambient Conditions ◽  
Luminescent Sensor ◽  
Sodium Calcium ◽  
Calcium Magnesium ◽  
Mercuric Ions ◽  
Ph Range

A chemoluminescent sensor utilizing the substrate 2,6-pyridinedicarboxaldehydebis(o-hydroxyphenylimine) (S1) was developed for low-concentration detection of mercuric ions in aqueous solutions. The sensor selectively detects mercury in the presence of sodium, calcium, magnesium, and iron ions. A strong binding was observed between the mercuric ions and the substrate at a pH range of 6.5–7.5, which makes the substrate a distinctive luminescence sensor for detecting mercury at ambient conditions. The sensor shows a linear response towards Hg2+ in the concentration range 5.0 × 10–5 to 2.5 × 10–8 M with a limit of detection of 5.0 × 10–8 M. The sensor can also detect zinc ions at a pH of 10 or higher. The results indicate that this sensor has a promising future for the detection of mercury in real environmental water samples.

Tubulin structure at intermediate resolution

1995 ◽  
Vol 53 ◽  
pp. 852-853
Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales
Keyword(s):  
High Resolution ◽  
Structural Data ◽  
Therapeutic Drug ◽  
Zinc Ions ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Negative Stain ◽  
Functional Mechanisms ◽  
Tubulin Structure

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.

Phospholipid Composition of Mitochondria of Gills of Pike (Esox lucius) under the Zinc Ions Impact

2013 ◽  
Vol 49 (6) ◽  
pp. 98-101
Author(s):  
Yu. I. Senyk ◽  
V. O. Khomenchuk ◽  
V. Z. Kurant ◽  
V. V. Grubinko
Keyword(s):  
Phospholipid Composition ◽  
Esox Lucius ◽  
Zinc Ions ◽  
Pike Esox Lucius

Formation of water chemistry in the Modonkul river under the action of mine drainage effluent

2020 ◽  
pp. 56-66
Author(s):  
Z. I. Khazheeva ◽  
S. S. Sanzhanova
Keyword(s):  
Water Chemistry ◽  
Mine Drainage ◽  
High Concentration ◽  
Catchment Basin ◽  
Sulfate Anion ◽  
Concentrated Flow ◽  
Sodium Calcium ◽  
Calcium Cation ◽  
Calcium Magnesium ◽  
The Town

The Dzhida ore field in the Zakamensk district of Buryatia features high concentration of mineralization within a small area. The Dzhida deposit is composed of complex ore. The ore field contains commercial-value primary deposits: Pervomai stockwork of molybdenum, Kholtoson tungsten lode and Inkur stockwork of tungsten. The Modonkul river catchment basin lies inside the Dzhida ore field. A real threat to the town of Zakamensk is created by manmade sand-bulk (old) tailings and slurry dump. By now, the concentrated flow of natural and man-made sand enters the low terrace and floodplain of the Modonkul river in the form of a talus train. This study is focused on the influence of the mine drainage effluent and the Inkur tributary on the water chemistry in the Modonkul river. 80 water samples were taken from the surface layer 0-0.5 m thick at five stations. Physicochemical indices of water were measured at the water sampling points, and the water chemistry was analyzed in a laboratory. In the background conditions, cations and anions in the Modonkul water chemistry range in decreasing order as follows: Са2+ > Mg2+ > Na++К+ и HCO - > SO 2- > Cl-. In the zone of mixture of natural and mine process water, the chemistry changes: from hydrocarbonate to sulfate (anion), from calcium-magnesium to sodium-calcium (cation). Downstream the natural chemistry changes to the hydrocabonate-sulfate composition, with prevailing content of calcium in cations. Iron content of water lowers 3-4 times after influx of mine effluents, while the contents of Mn, Zn, Co and Cd grow and then decrease downstream.

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