Removal of heavy metal ions from wastewaters: A review

Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer's disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases.

Acetylcholinesterase Inhibitors: Pharmacology and Toxicology

Adsorption of heavy metals on conventional and nanostructured materials for wastewater treatment purposes: A review

Cholinesterase Inhibitors in Alzheimer's Disease

Triggered by the resounding success of cisplatin, the past decades have seen tremendous efforts to produce clinically beneficial analogues. The recent achievement of oxaliplatin for the treatment of colon cancer should, however, not belie the imbalance between a plethora of investigated complexes and a very small number of clinically approved platinum drugs. Strategies opening up new avenues are increasingly being sought using complexes of metals other than platinum such as ruthenium or gallium. Based on the chemical differences between these metals, the spectrum of molecular mechanisms of action and potential indications can be broadened substantially. Other approaches focus on complexes with tumour-targeting properties, thereby maximizing the impact on cancer cells and minimizing the problem of adverse side effects, and complexes with biologically active ligands.

Antitumour metal compounds: more than theme and variations

Kinetics of 1,8-dihydroxy-2-(pyrazol-5-ylazo)-naphthalene-3,6- disulphonic acid immobilization on anion exchangers

Kinetics of the reaction of S-carboxymethyl-L-cysteine with palladium(II) chloride.

Kinetics of chelate formation between PdII and S-carboxymethyl-L-cystein

The equilibria of the complex formation between AuCl4-n(OH)n - and I- was
 studied spectrophotometrically in aqueous solutions containing KI:Au(III)£2
 in the acidity range from 1 M HCl to pH 7 at 25oC. From the hydrogen ion
 and Cl-ion dependence of the absorption spectra, it was found that AuCl2I2
 - and Au(OH)2I2 - complexes were formed. The equilibrium constants of
 complex formation were determined.

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Spectrophotometric investigations of the reaction between gold(III) and potassium iodide

The influence of malathion and its four main degradation products found in irradiated solutions (malaoxon, isomalathion, diethyl maleate and O,O-dimethyl phosphate) on acetylcholinesterase (AChE) of free and immobilized bovine erythrocytes was investigated. The concentration-dependent responses to malathion and related organophosphates, malaoxon and isomalathion, of both AChE bioassays used were obtained. The IC50 values for free and immobilized AChE (3.7 ± 0.2) × 10−4 M/(1.6 ± 0.1) × 10−4, (2.4 ± 0.3) × 10−6/(3.4 ± 0.1) × 10−6 M, and (3.2 ± 0.3) × 10−6 M/(2.7 ± 0.2) × 10−6 M were obtained in the presence of malathion, malaoxon and isomalathion, respectively. However, diethyl maleate inhibited AChE activity at concentrations >-10 mM, while O,O-dimethyl phosphate did not noticeably affect enzyme activity at all investigated concentrations. The relation between the structure of the compounds and their ability to inhibit enzyme activity was discussed.

Vesna Vasić

Papers

Kinetics of 1,8-dihydroxy-2-(pyrazol-5-ylazo)-naphthalene-3,6- disulphonic acid immobilization on anion exchangers

Kinetics of the reaction of S-carboxymethyl-L-cysteine with palladium(II) chloride.

Kinetics of chelate formation between PdII and S-carboxymethyl-L-cystein

Spectrophotometric investigations of the reaction between gold(III) and potassium iodide

The Influence of Malathion and Its Decomposition Products on Free and Immobilized Acetylcholinesterase1