scholarly journals Correction: Variable coordination and C–S bond cleavage activity of N-substituted imidazolidine-2-thiones towards copper: synthesis, spectroscopy, structures, ESI-mass and antimicrobial studies

2017 ◽  
Vol 46 (43) ◽  
pp. 15138-15138
Author(s):  
Jaspreet K. Aulakh ◽  
Tarlok S. Lobana ◽  
Henna Sood ◽  
Daljit S. Arora ◽  
Isabel Garcia-Santos ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Dalton Trans ◽  
Cleavage Activity ◽  
Antimicrobial Studies ◽  
Variable Coordination

Correction for ‘Variable coordination and C–S bond cleavage activity of N-substituted imidazolidine-2-thiones towards copper: synthesis, spectroscopy, structures, ESI-mass and antimicrobial studies’ by Jaspreet K. Aulakh, et al., Dalton Trans., 2017, 46, 1324–1339.

Variable coordination and C–S bond cleavage activity of N-substituted imidazolidine-2-thiones towards copper: synthesis, spectroscopy, structures, ESI-mass and antimicrobial studies

2017 ◽  
Vol 46 (4) ◽  
pp. 1324-1339 ◽  
Author(s):  
Jaspreet K. Aulakh ◽  
Tarlok S. Lobana ◽  
Henna Sood ◽  
Daljit S. Arora ◽  
Isabel Garcia-Santos ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Bond Cleavage ◽  
Living Cells ◽  
Cleavage Activity ◽  
Antimicrobial Studies ◽  
Variable Coordination

N-substituted imidazoldine-2-thiones with copper(i) halides have shown variable nuclearity, C–S bond cleavage, antimicrobial activity and non-toxicity in some cases to living cells.

Cytosolic CP bond cleavage activity in bacterial cells isolated from soil

1991 ◽  
Vol 71 (2) ◽  
pp. 128-130 ◽  
Author(s):  
Nobue Osamura ◽  
Kousaku Murata ◽  
Akira Kimura
Keyword(s):  
Bond Cleavage ◽  
Bacterial Cells ◽  
Cleavage Activity

scholarly journals A Novel Mechanism for Resistance to the Antimetabolite N -Phosphonoacetyl-l-Aspartate by Helicobacter pylori

1998 ◽  
Vol 180 (21) ◽  
pp. 5574-5579 ◽  
Author(s):  
Brendan P. Burns ◽  
George L. Mendz ◽  
Stuart L. Hazell
Keyword(s):  
Helicobacter Pylori ◽  
Nmr Spectroscopy ◽  
De Novo ◽  
Bond Cleavage ◽  
Substrate Inhibition ◽  
Mechanism Of Resistance ◽  
Cleavage Activity ◽  
Compound C ◽  
Aspartase Activity ◽  
H Pylori

ABSTRACT The mechanism of resistance toN-phosphonoacetyl-l-aspartate (PALA), a potent inhibitor of aspartate carbamoyltransferase (which catalyzes the first committed step of de novo pyrimidine biosynthesis), inHelicobacter pylori was investigated. At a 1 mM concentration, PALA had no effects on the growth and viability ofH. pylori. The inhibitor was taken up by H. pylori cells and the transport was saturable, with aKm of 14.8 mM and aV max of 19.1 nmol min−1 μl of cell water−1. By 31P nuclear magnetic resonance (NMR) spectroscopy, both PALA and phosphonoacetate were shown to have been metabolized in all isolates of H. pyloristudied. A main metabolic end product was identified as inorganic phosphate, suggesting the presence of an enzyme activity which cleaved the carbon-phosphorus (C-P) bonds. The kinetics of phosphonate group cleavage was saturable, and there was no evidence for substrate inhibition at higher concentrations of either compound. C-P bond cleavage activity was temperature dependent, and the activity was lost in the presence of the metal chelator EDTA. Other cleavages of PALA were observed by 1H NMR spectroscopy, with succinate and malate released as main products. These metabolic products were also formed when N-acetyl-l-aspartate was incubated with H. pylori lysates, suggesting the action of an aspartase. Studies of the cellular location of these enzymes revealed that the C-P bond cleavage activity was localized in the soluble fraction and that the aspartase activity appeared in the membrane-associated fraction. The results suggested that the twoH. pylori enzymes transformed the inhibitor into noncytotoxic products, thus providing the bacterium with a mechanism of resistance to PALA toxicity which appears to be unique.

Pharmacognostical fingerprinting and selective bioactivity studies of Solanum glaucophyllum Desf.

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Anindya Sundar Ray ◽  
Suman Kalyan Mandal ◽  
Chowdhury Habibur Rahaman
Keyword(s):  
Medicinal Plant ◽  
Radical Scavenging ◽  
Ethanol Extract ◽  
Inhibition Zone ◽  
Phytochemical Analysis ◽  
Antimicrobial Studies ◽  
Maximum Inhibition ◽  
Crude Drugs ◽  
Phytochemical Studies ◽  
Dpph Radical Scavenging

Solanum glaucophyllum Desf. (Solanaceae) is traditionally used for curing several health conditions in both human and domesticated animals. There is no data available regarding pharmacognostic standardization and pharmacological activity of this less known medicinal plant. Therefore, the aim of the present work is to prepare pharmacognostic fingerprints of crude drugs obtained from the leaf and stem parts of S. glaucophyllum. Apart from this detailed phytochemical analysis, antioxidant and antimicrobial studies have also been carried out. Pharmacognostic study revealed that the leaves are amphistomatic and stomata are strictly of anisocytic type. Values of stomatal index, palisade ratio, ash content of the investigated parts are found distinct and can be used as pharmacognostic standards for evaluation of crude drugs of this medicinal plant. Phytochemical studies of the leaf and stem parts indicated that phenolics, flavonoids, tannins and alkaloids are present in quite impressible amount. Curcumin content in stem was found very high through HPLC analysis. In DPPH radical scavenging assay, the stem part showed significant antioxidant potential. Ethanol extract of stem produced maximum inhibition zone (11mm) against Pseudomonas aeruginosa at the concentration of 50 mg/ml among five test microorganisms. Some pharmacognostic features recorded in this study as diagnostic ones will help in proper identification of this ethnomedicinal plant in its fresh as well as dried form. On the other hand preliminary phytochemical, antioxidant and antimicrobial studies highlight the S. glaucophyllum as a promising candidate for bioprospecting.

Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

2020 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada Wheelaghan ◽  
Sandra Aristizábal ◽  
Robert Fayzullin ◽  
Shrinwantu Pal ◽  
...  
Keyword(s):  
Alkyl Group ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Terminal Alkyne ◽  
Alkyl Aryl ◽  
Metal Metal ◽  
The Stability ◽  
Selective Formation ◽  
Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

Room Temperature Alkali Metal Reduction of Carbon Dioxide

2020 ◽  
Author(s):  
Lucas A. Freeman ◽  
Akachukwu D. Obi ◽  
Haleigh R. Machost ◽  
Andrew Molino ◽  
Asa W. Nichols ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Alkali Metals ◽  
Room Temperature ◽  
Chemical Reduction ◽  
Bond Cleavage ◽  
Open Shell ◽  
Metal Reduction ◽  
One Pot ◽  
Earth Abundant ◽  
Electron Reduction

The reduction of the relatively inert carbon–oxygen bonds of CO<sub>2</sub> to access useful CO<sub>2</sub>-derived organic products is one of the most important fundamental challenges in synthetic chemistry. Facilitating this bond-cleavage using earth-abundant, non-toxic main group elements (MGEs) is especially arduous because of the difficulty in achieving strong inner-sphere interactions between CO<sub>2</sub> and the MGE. Herein we report the first successful chemical reduction of CO<sub>2</sub> at room temperature by alkali metals, promoted by a cyclic(alkyl)(amino) carbene (CAAC). One-electron reduction of CAAC-CO<sub>2</sub> adduct (<b>1</b>) with lithium, sodium or potassium metal yields stable monoanionic radicals clusters [M(CAAC–CO<sub>2</sub>)]<sub>n</sub>(M = Li, Na, K, <b> 2</b>-<b>4</b>) and two-electron alkali metal reduction affords open-shell, dianionic clusters of the general formula [M<sub>2</sub>(CAAC–CO<sub>2</sub>)]<sub>n </sub>(<b>5</b>-<b>8</b>). It is notable that these crystalline clusters of reduced CO<sub>2</sub> may also be isolated via the “one-pot” reaction of free CO<sub>2</sub> with free CAAC followed by the addition of alkali metals – a reductive process which does not occur in the absence of carbene. Each of the products <b>2</b>-<b>8</b> were investigated using a combination of experimental and theoretical methods.<br>

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