Influence of Metal Ions and of Metal Complexes on the Hydrolysis of Salicyl Phosphate

1962 ◽  
Vol 84 (16) ◽  
pp. 3041-3046 ◽  
Author(s):  
Robert. Hofstetter ◽  
Yukito. Murakami ◽  
George. Mont ◽  
Arthur E. Martell
Keyword(s):  
Metal Ions ◽  
Metal Complexes ◽  
Hydrolysis Of

Synthesis, Characterization and in vitro Biological Evaluation of a New Schiff Base Derived from Drug and its Complexes with Transition Metal Ions

2018 ◽  
Vol 69 (7) ◽  
pp. 1678-1681
Author(s):  
Amina Mumtaz ◽  
Tariq Mahmud ◽  
M. R. J. Elsegood ◽  
G. W. Weaver
Keyword(s):  
Schiff Base ◽  
Transition Metal ◽  
Metal Ions ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Free Ligand ◽  
Transition Metal Ions ◽  
Biological Evaluation ◽  
Pyridoxal Hydrochloride

New series of copper (II), cobalt (II), zinc (II), nickel (II), manganese (II), iron (II) complexes of a novel Schiff base were prepared by the condensation of sulphadizine and pyridoxal hydrochloride. The ligand and metal complexes were characterized by utilizing different instrumental procedures like microanalysis, thermogravimetric examination and spectroscopy. The integrated ligand and transition metal complexes were screened against various bacteria and fungus. The studies demonstrated the enhanced activity of metal complexes against reported microbes when compared with free ligand.

scholarly journals Carbonic Anhydrase Inhibitors Part 721 Synthesis and Antiglaucoma Properties of Metal Complexes of p-Fluorobenzolamide

1999 ◽  
Vol 6 (2) ◽  
pp. 67-73 ◽  
Author(s):  
Claudiu T. Supuran ◽  
Andrea Scozzafava ◽  
Luca Menabuoni ◽  
Francesco Mincione ◽  
Fabrizio Briganti ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Carbonic Anhydrase ◽  
Metal Ions ◽  
Metal Complexes ◽  
Carbonic Anhydrase Inhibitors ◽  
Physico Chemical ◽  
New Compounds

Metal complexes of a heterocyclic sulfonamides possessing very strong carbonic anhydrase (CA) inhibitory properties, i.e., 5-(p-fluorobenzenesulfonylamido)-1,3,4-thiadiazole-2-sulfonamide (p-fluorobenzolamide) were prepared. The new complexes contained metal ions such as Zn(II), Cu(II), Co(II), Ni(II), Cd(II) and Mn(II). The new compounds were characterized by standard physico-chemical procedures, and assayed as inhibitors of three CA isozymes, CA I, II and IV. Very good inhibition has been evidenced both for the parent sulfonamides as well as for the prepared complexes, against all three investigated isozymes. Some of these new complexes as well as the parent sulfonamide, strongly lowered intraocular pressure (IOP) in normotensive rabbits when administered as a 2% solution into the eye.

Hydrolysis of 5′,5′-Tri- or Tetraphosphate-mRNA 5′-cap Analogs Promoted by Cu2+or Zn2+Metal Ions

2011 ◽  
Vol 30 (2) ◽  
pp. 135-148 ◽  
Author(s):  
Alicja Stachelska-Wierzchowska ◽  
Zbigniew J. Wieczorek
Keyword(s):  
Metal Ions ◽  
Hydrolysis Of

scholarly journals Hydrolysis of Metal Ions in Cation Exchange Resin

1961 ◽  
Vol 82 (12) ◽  
pp. 1650-1653
Author(s):  
Hiroyuki TSUBOT ◽  
Hidetake KAKIHANA
Keyword(s):  
Metal Ions ◽  
Cation Exchange ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Hydrolysis Of

Radioactive Tracer Study Performed in a Dipole Geometry in a Highly Conductive Fracture Zone

1990 ◽  
Vol 212 ◽  
Author(s):  
Johan Byegård ◽  
Gunnar Skarnemark ◽  
Mats Skålberg
Keyword(s):  
Metal Ions ◽  
Metal Complexes ◽  
Fracture Zone ◽  
Radioactive Tracer ◽  
Tracer Experiment ◽  
Tracer Study ◽  
Redox Potentials ◽  
Chemical Analogue

ABSTRACTA radioactive tracer experiment has been performed in a highly conductive fracture zone, using a dipole geometry. Anions (131I− and 82Br−) and complexed metal ions (51Cr-EDTA, 58Co-EDTA, 111In-EDTA, 140La-DOTA, 160Tb-EDTA, 169Yb-EDTA and 177Lu-DOTA) have been injected and their properties as non-sorbing tracers were evaluated. Besides, studies of slightlysorbing cations (24Na+, 58Co2+, 86Rb+ and 201T1+) were performed. 99mTcO4 and its chemical analogue 186ReO4 were also injected to study the behaviour of Tc at low redox-potentials. Breakthrough was obtained for Re and for all metal complexes and anions. Some differences in the recovery yields could be seen. No transport of cations, except for Na, could be measured. No breakthrough of Tc could be observed. This indicates that TcO4− was reduced and sorbed.

scholarly journals The Hydrolysis of Pyridylmethyl Phosphates and the Catalysis of Metal Ions

1967 ◽  
Vol 40 (11) ◽  
pp. 2724-2724 ◽  
Author(s):  
Yukito Murakami ◽  
Makoto Takagi
Keyword(s):  
Metal Ions ◽  
Hydrolysis Of

Catalytic Hydrolysis of Phosphate Diester with Metal Complexes of Macrocyclic Tetraamine in Comicellar Solution

2010 ◽  
Vol 19 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Qing-Xiang Xiang ◽  
Xiao-Qi Yu ◽  
Jing-Song You ◽  
Qian-Shun Yan ◽  
Rn-Gang Xie
Keyword(s):  
Metal Complexes ◽  
Catalytic Hydrolysis ◽  
Phosphate Diester ◽  
Hydrolysis Of

scholarly journals Pectin methylesterase, metal ions and plant cell-wall extension. Hydrolysis of pectin by plant cell-wall pectin methylesterase

1991 ◽  
Vol 279 (2) ◽  
pp. 343-350 ◽  
Author(s):  
J Nari ◽  
G Noat ◽  
J Ricard
Keyword(s):  
Cell Wall ◽  
Metal Ions ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Direct Interaction ◽  
Enzyme Reaction ◽  
Pectin Methylesterase ◽  
High Concentrations ◽  
Enzyme Molecules ◽  
Hydrolysis Of

The hydrolysis of p-nitrophenyl acetate catalysed by pectin methylesterase is competitively inhibited by pectin and does not require metal ions to occur. The results suggest that the activastion by metal ions may be explained by assuming that they interact with the substrate rather than with the enzyme. With pectin used as substrate, metal ions are required in order to allow the hydrolysis to occur in the presence of pectin methylesterase. This is explained by the existence of ‘blocks’ of carboxy groups on pectin that may trap enzyme molecules and thus prevent the enzyme reaction occurring. Metal ions may interact with these negatively charged groups, thus allowing the enzyme to interact with the ester bonds to be cleaved. At high concentrations, however, metal ions inhibit the enzyme reaction. This is again understandable on the basis of the view that some carboxy groups must be adjacent to the ester bond to be cleaved in order to allow the reaction to proceed. Indeed, if these groups are blocked by metal ions, the enzyme reaction cannot occur, and this is the reason for the apparent inhibition of the reaction by high concentrations of metal ions. Methylene Blue, which may be bound to pectin, may replace metal ions in the ‘activation’ and ‘inhibition’ of the enzyme reaction. A kinetic model based on these results has been proposed and fits the kinetic data very well. All the available results favour the view that metal ions do not affect the reaction through a direct interaction with enzyme, but rather with pectin.

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