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Journal ArticleDOI

The synthesis and in vitro acetylcholinesterase and butyrylcholinesterase inhibitory activity of tacrine (Cognex®) derivaties

01 Aug 1992-Bioorganic & Medicinal Chemistry Letters (Pergamon)-Vol. 2, Iss: 8, pp 861-864
TL;DR: Chlorosubstituted derivatives of tacrine, 1,4-methylenetacrine, and their in vitro acetylcholinesterase and butyrylcholiersterase inhibitory activities are described.
About: This article is published in Bioorganic & Medicinal Chemistry Letters.The article was published on 1992-08-01. It has received 46 citations till now. The article focuses on the topics: Tacrine & Butyrylcholinesterase.
Citations
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Journal ArticleDOI
Hachiro Sugimoto1, Hiroo Ogura1, Yasuo Arai1, Youichi Iimura1, Yoshiharu Yamanishi1 
TL;DR: Donepezil showed several positive characteristics including the following: It has a novel structure compared to other conventional ChE inhibitors; it shows strong anti-AChE activity and has long lasting efficacy; the inhibitory characteristic of donepezil shows that it is highly selective for AChE as compared to butyrylcholinesterase (BuChE) and showed reversibility.

190 citations

Journal ArticleDOI
TL;DR: The development of bivalent ligands that occupy both the active and the peripheral site of AChE might be more beneficial for treatment of Alzheimer´s disease than simple inhibition of the acetylcholine hydrolysis.
Abstract: Neurodegenerative disorders, such as Alzheimer's disease, are often characterised by the degeneration of the cholinergic system. Thus, the aim of many treatment regimens is to support this system either by means of muscarinic agonists or by inhibitors of acetylcholinesterase (AChE), the latter being able to increase the concentration of acetylcholine. However, both pharmacological groups of drugs can only help in the beginning of the progressive disease. The finding that the occupation of the peripheral anionic site of AChE is able to stop the formation of the amyloid plaque led to the development of bivalent ligands that occupy both the active and the peripheral site. This dual action might be more beneficial for treatment of Alzheimer s disease than simple inhibition of the acetylcholine hydrolysis. Thus, the new bivalent ligands are the focus of this review.

180 citations

Journal ArticleDOI
TL;DR: Two isomeric series of dual binding site acetylcholinesterase (AChE) inhibitors that retain the potent and selective human AChE inhibitory activity of the parent 6-chlorotacrine while exhibiting a significant in vitro inhibitoryActivity toward the AChe-induced and self-induced Abeta aggregation and toward BACE-1, as well as ability to enter the central nervous system, which makes them promising anti-Alzheimer lead compounds.
Abstract: Two isomeric series of dual binding site acetylcholinesterase (AChE) inhibitors have been designed, synthesized, and tested for their ability to inhibit AChE, butyrylcholinesterase, AChE-induced and self-induced β-amyloid (Aβ) aggregation, and β-secretase (BACE-1) and to cross blood−brain barrier. The new hybrids consist of a unit of 6-chlorotacrine and a multicomponent reaction-derived pyrano[3,2-c]quinoline scaffold as the active-site and peripheral-site interacting moieties, respectively, connected through an oligomethylene linker containing an amido group at variable position. Indeed, molecular modeling and kinetic studies have confirmed the dual site binding of these compounds. The new hybrids, and particularly 27, retain the potent and selective human AChE inhibitory activity of the parent 6-chlorotacrine while exhibiting a significant in vitro inhibitory activity toward the AChE-induced and self-induced Aβ aggregation and toward BACE-1, as well as ability to enter the central nervous system, which ...

163 citations

Journal ArticleDOI
TL;DR: This study attempted to derive a comprehensive SAR picture for the class of acetylcholinesterase (AChE) inhibitors related to tacrine, a drug currently in use for the treatment of the Alzheimer's disease.
Abstract: In this study, we attempted to derive a comprehensive SAR picture for the class of acetylcholinesterase (AChE) inhibitors related to tacrine, a drug currently in use for the treatment of the Alzheimer's disease. To this aim, we synthesized and tested a series of 9-amino-1,2,3,4-tetrahydroacridine derivatives substituted in the positions 6 and 7 of the acridine nucleus and bearing selected groups on the 9-amino function. By means of the Hansch approach, QSAR equations were obtained, quantitatively accounting for both the detrimental steric effect of substituents in position 7 and the favorable electron-attracting effect exerted by substituents in positions 6 and 7 of the 9-amino-1,2,3,4-tetrahydroacridine derivatives. The three-dimensional (3D) properties of the inhibitors were taken into consideration by performing a CoMFA analysis on the series of AChE inhibitors made by 12 9-amino-1,2,3,4-tetrahydroacridines and 13 11H-indeno[1,2-b]quinolin-10-ylamines previously developed in our laboratory. The alignme...

144 citations

References
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Journal ArticleDOI
23 Aug 1991-Science
TL;DR: Modeling of acetylcholine binding to the enzyme suggests that the quaternary ammonium ion is bound not to a negatively charged "anionic" site, but rather to some of the 14 aromatic residues that line the gorge.
Abstract: The three-dimensional structure of acetylcholinesterase from Torpedo californica electric organ has been determined by x-ray analysis to 2.8 angstrom resolution. The form crystallized is the glycolipid-anchored homodimer that was purified subsequent to solubilization with a bacterial phosphatidylinositol-specific phospholipase C. The enzyme monomer is an alpha/beta protein that contains 537 amino acids. It consists of a 12-stranded mixed beta sheet surrounded by 14 alpha helices and bears a striking resemblance to several hydrolase structures including dienelactone hydrolase, serine carboxypeptidase-II, three neutral lipases, and haloalkane dehalogenase. The active site is unusual because it contains Glu, not Asp, in the Ser-His-acid catalytic triad and because the relation of the triad to the rest of the protein approximates a mirror image of that seen in the serine proteases. Furthermore, the active site lies near the bottom of a deep and narrow gorge that reaches halfway into the protein. Modeling of acetylcholine binding to the enzyme suggests that the quaternary ammonium ion is bound not to a negatively charged "anionic" site, but rather to some of the 14 aromatic residues that line the gorge.

2,489 citations

Journal ArticleDOI
TL;DR: It is suggested that THA may be at least temporarily useful in the long-term palliative treatment of patients with Alzheimer's disease, and further observations will be required before a clear assessment of the role of this agent can be made.
Abstract: We treated 17 patients who had moderate to severe Alzheimer's disease with oral tetrahydroaminoacridine (THA), a centrally active anticholinesterase, in a three-phase study. In the nonblinded first phase of the study, significant improvement occurred in subjects who received the drug, as compared with their pretreatment status, on the global assessment (P = 0.001), the Orientation Test (P = 0.001), and the more sophisticated Names Learning Test (P = 0.001). During the second phase, the subjects served as their own controls in a double-blind, placebo-controlled, cross-over study in which the order of administration of the drug and placebo was randomly assigned. Among the 14 subjects completing Phase II, THA treatment produced significantly better results than placebo on the global assessment (P = 0.003), the Orientation Test (P = 0.004), the Alzheimer's Deficit Scale (P = 0.003), and the Names Learning Test (P = 0.001). Twelve subjects have entered Phase III, which involves long-term administration of oral THA. The average duration of treatment in these subjects at present is 12.6 months; symptomatic improvements have occurred, and no serious side effects attributable to THA have been observed. These encouraging initial results suggest that THA may be at least temporarily useful in the long-term palliative treatment of patients with Alzheimer's disease. We stress that further observations will be required before a clear assessment of the role of this agent can be made.

1,079 citations

Journal ArticleDOI
TL;DR: A rapid and simple radiometric assay for cholinesterase, suitable for multiple determinations, has been developed, highly reproducible, quite sensitive, and useful for applications in which multiple samples must be quickly assayed.

674 citations

Journal ArticleDOI
TL;DR: It is suggested that an adequate test of the efficacy of ChE inhibition may await the use of new and improved ChE inhibitors that produce significantly fewer side effects and greater therapeutic effects than drugs presently being tested for efficacy in the treatment of SDAT patients.
Abstract: Senile dementia of the Alzheimer type (SDAT) is a degenerative disease of the brain that affects up to 20% or more of individuals who live beyond 80 years of age. A deficiency of cholinergic function is expected to play a major role in the development of SDAT psychopathology. Possible existence of an underactive cholinergic system has led to clinical trials of cholinomimetic drugs to attempt to reverse the deficit in SDAT. Some improvement in memory function has followed the administration of cholinesterase (ChE) inhibitors, but in general the affected individuals have not been returned to normal or mildy impaired mental functions or activities of daily living functioning. This paper is a critical review of results of acute and chronic trials performed with ChE inhibitors in experimental animals and humans. We also review and discuss mechanisms of decvelopment of pharmacological behavioral tolerance to ChE inhibitors. Behavioral changes following ChE inhibition appear to coincide with predicted peak levels of acetulcholine (ACh) concentration in the brain. Yet we find an inconsistent relationship among the degree of ChE inhibition, changes in brain acetylcholine concentrations, and behavioral changes, both therapeutic and adverse effects, following administration of ChE inhibitors. ChE inhibition is associated with distressing adverse effects. The therapeutic effects of increased ACh levels in the brain may be masked by these side effects. We suggest that an adequate test of the efficacy of ChE inhibition may await the use of new and improved ChE inhibitors that produce significantly fewer side effects and greater therapeutic effects than drugs presently being tested for efficacy in the treatment of SDAT patients.

203 citations

Journal ArticleDOI
TL;DR: These compounds are related to 1,2,3,4-tetrahydro-9-acridinamine and inhibit acetylcholinesterase in vitro and are active in a model that may be predictive of activity in Alzheimer's disease--the scopolamine-induced impairment of 24-h memory of a passive dark-avoidance paradigm in mice.
Abstract: The synthesis of a series of 9-amino-1,2,3,4-tetrahydroacridin-1-ols is reported. These compounds are related to 1,2,3,4-tetrahydro-9-acridinamine (THA, tacrine). They inhibit acetylcholinesterase in vitro and are active in a model that may be predictive of activity in Alzheimer's disease--the scopolamine-induced impairment of 24-h memory of a passive dark-avoidance paradigm in mice. Two compounds, (+/-)-9-amino-1,2,3,4-tetrahydroacridin-1-ol maleate (1a, HP-029) and (+/-)-9-(benzylamino)-1,2,3,4-tetrahydroacridin-1-ol maleate (1p, HP-128), were also active in reversing the deficit in 72-h retention of a one-trial dark-avoidance task in rats, induced by ibotenic acid lesions in the nucleus basalis magnocellularis. In addition, compound 1 p showed potent in vitro inhibition of the uptake of radiolabeled noradrenaline and dopamine (IC50 = 0.070 and 0.30 microM, respectively). Compounds 1a and 1p, which showed less acute toxicity in both rats and mice than THA, are in phase II and phase I clinical trials, respectively, for Alzheimer's disease.

102 citations

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