Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.7 (acetylcholinesterase)
28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three xanthones, polyanxanthone A (1), B (2) and C (3) have been isolated from the methanol extract of the wood trunk of Garcinia polyantha, along with five known xanthones: 1,3,5-trihydroxyxanthone (4); 1,5-dihydroxyxanthone (5); 1,3,6,7-tetrahydroxyxanthone (6); 1,6-dihydroxy-5-methoxyxanthone (7) and 1,3,5,6-tetrahydroxyxanthone (8). Their structures were determined by means of 1D- and 2D-NMR techniques. Some of the above compounds were screened for their anticholinesterase activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes.
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PMID:Polyanxanthone A, B and C, three xanthones from the wood trunk of Garcinia polyantha Oliv. 1802 54

New acetylcholinesterase reactivators with either a (E) or (Z)-but-2-ene connecting linker were recently prepared. The purity of the compounds was checked by HPLC and was found to be sufficient for in-vitro screening. All the discussed bispyridinium reactivators were analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) to measure lipophilicity. The procedure was performed under isocratic conditions with methanol as organic modifier in the mobile phase using an end-capped non-polar C(18) stationary phase RP column. Relationships between the lipophilicity (logarithm of the RP-HPLC capacity factor, log k) and chemical structures of the studied compounds are discussed. Lipophilicity was different for the (E) and (Z) compounds and varied among the compounds in each of these groups. The lipophilicity differences also indicated an apparent influence of intramolecular interactions. Lipophilicity calculations (log P/Clog P) by means of commonly used software were not successful due to the presence of quaternary nitrogen atoms in the molecules of the reactivators.
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PMID:RP-HPLC determination of the lipophilicity of bispyridinium reactivators of acetylcholinesterase bearing a but-2-ene connecting linker. 1836 2

A purified phosphotriesterase was successfully immobilized onto trityl agarose in a fixed bed reactor. A total of up to 9200 units of enzyme activity was immobilized onto 2.0 mL of trityl agarose (65 micromol trityl groups/mL agarose), where one unit is the amount of enzyme required to catalyze the hydrolysis of one micromole of paraoxon in one min. The immobilized enzyme was shown to behave chemically and kinetically similar to the free enzyme when paraoxon was utilized as a substrate. Several organophosphate pesticides, methyl parathion, ethyl parathion, diazinon, and coumaphos were also hydrolyzed by the immobilized phosphotriesterase. However, all substrates exhibited an affinity for the trityl agarose matrix. For increased solubility and reduction in the affinity of these pesticides for the trityl agarose matrix, methanol/water mixtures were utilized. The effect of methanol was not deleterious when concentrations of less than 20% were present. However, higher concentrations resulted in elution of enzyme from the reactor. With a 10-unit reactor, a 1.0 mM paraoxon solution was hydrolyzed completely at a flow rate of 45 mL/h. Kinetic parameters were measured with a 0.1-unit reactor with paraoxon as a substrate at a flow rate of 22 mL/h. The apparent K(m) for the immobilized enzyme was 3-4 times greater than the K(m) (0.1 mM) for the soluble enzyme. Immobilization limited the maximum rate of substrate hydrolysis to 40% of the value observed for the soluble enzyme. The pH-rate profiles of the soluble and immobilized enzymes were very similar. The immobilization of phosphotriesterase onto trityl agarose provides an effective method esterase onto trityl agarose provides an effective method for hydrolyzing and thus detoxifyuing organophosphate pesticides and mammalian acetylcholinesterase inhinbitors.
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PMID:Detoxification of organophosphate pesticides using an immobilized phosphotriesterase from Pseudomonas diminuta. 1859 46

A significant acetylcholinesterase inhibitory activity was observed for the ethyl acetate and methanol extracts from the leaves and the fruits of MYRISTICA CRASSA. Three new dimeric acylphenols, giganteone C ( 5), maingayones B and C ( 6 and 7) were isolated together with the known malabaricones B and C ( 2 and 3) and giganteone A ( 4). Compounds 2 and 3 possess significant inhibitory activity on acetylcholinesterase. LC/MS study was particularly useful to discriminate structures of compounds 6 and 7.
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PMID:Acylphenols from Myristica crassa as new acetylcholinesterase inhibitors. 1867 Nov 98

The brain insulin receptor and ERK I/II are known to play an important role in memory formation and neuroprotection. A series of experiments was designed to explore if Liriopsis tuber (LT) extracts could exhibit neuroprotection and memory enhancing actions. LT was extracted with 70% methanol and subsequently fractionated into chloroform (fraction C), chloroform/methanol-(3:1) (fraction CM), methanol-soluble (fraction M) and methanol-insoluble, water-soluble fractions (fraction A). The LT fractions (T, C, M, A) significantly inhibited the cortical depolarization induced by AMPA in cortical slices of rats. In addition, these fractions were also effective in promoting memory in the passive avoidance test in mice. To gain insight into the mechanism of memory enhancing effects by Liriopsis tuber extracts, the activities of hippocampal insulin receptors and ERK I/II were tested in rats. Extract of LT (T) dramatically stimulated tyrosine phosphorylation of the insulin receptor, while fraction C of LT also significantly stimulated the same. In addition, ERK I/II were stimulated and cholinesterase activities were inhibited by fractions T, C, M and A in the rat hippocampus. These results suggest that Liriopsis tuber extracts may exert neuroprotection and memory enhancing effects via activation of the insulin receptor and ERK I/II as well as inhibiting cholinesterase.
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PMID:Extracts of Liriopsis tuber protect AMPA induced brain damage and improve memory with the activation of insulin receptor and ERK I/II. 1880 26

Flow microcalorimetry has been applied to the determination of organophosphorus pesticides by inhibition of cholinesterase. One direct inhibitor (TEPP) and one latent inhibitor (parathion) were investigated. The former is determinable at concentrations of about 10(-6)M and the latter at about 10(-4)M. The inhibitory power of parathion is increased if methanol is used as solvent.
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PMID:Application of flow microcalorimetry to analytical problems-I. Determination of organophosphorus pesticides by inhibition of cholinesterase. 1896 Dec 36

A novel biosensor assay format for aflatoxin based on acetylcholinesterase (AChE) inhibition by aflatoxin B(1) (AFB(1)) is proposed. The AChE was present in solution and an amperometric choline oxidase biosensor was used for monitoring its residual activity. To create the biosensor, the choline oxidase was immobilized by cross-linking onto screen-printed electrodes modified with Prussian Blue (PB) and these were used to detect the H(2)O(2) at low potential (-0.05V versus a screen-printed internal silver pseudoreference electrode). For the development of the AFB(1) assay, several parameters such as AChE and substrate concentration, the methanol effect, and pH were evaluated and optimized. The linear working range was assessed to be 10-60ppb. Concentrations as low as 2ppb, which correspond to the legal limit of AFB(1) in food for humans, were detected after a pre-concentration step. The suitability of the method was evaluated using commercial olive oil samples. A recovery equal to 78+/-9% for 10ppb of AFB(1) in olive oil samples was obtained.
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PMID:Development of a bio-electrochemical assay for AFB1 detection in olive oil. 1902 30

Storage instability is one of the serious problems that greatly restrict pesticide use. Routine checks on the composition and toxicity of 30% emulsifiable concentrates (EC) of chloramidophos (CP) during storage indicated that 78.6% of the active ingredient had decreased, whereas the anti-acetylcholinesterase (AChE) activity of the formulation was potentiated by 3.5 times. To understand the mechanism for these changes, detailed knowledge of the products present and their effects on anti-AChE potential deserves attention. It was likely that the basis for these changes was methanol, the cosolvent of CP EC, because when the purified CP was stored in methanol at 50 degrees C for 2 weeks, CP drop and toxic potentiation similar to those observed in CP EC also appeared. The major products of the CP-methanol reaction mixture were isolated and identified by HPLC and GC-MS, respectively, and their inhibitory potentials against AChE and effectiveness as potentiators were assessed. Following redetermination of the main product (O,S-dimethyl-[(2,2,2)-trichloro-1-methoxyethyl]phosphoramidothioate (MCP)) and high anti-AChE material (methamidophos), which were preconfirmed in the reaction mixture in CP EC, it was successfully demonstrated that the majority of CP in the formulation had been transformed to a new stable compound, MCP. Meanwhile, formation of another product, methamidophos, resulted in toxic potentiation.
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PMID:Mechanisms of composition change and toxic potentiation of chloramidophos emulsifiable concentrate during storage. 1913 86

This article reports the results of selected biological activities, including anticholinesterase, antioxidant, antibacterial, antifungal and antiviral properties, of the petroleum ether, chloroform and methanol extracts as well as the alkaloid fraction of Lycopodium complanatum L. ssp. chamaecyparissus (A. Br.) Doll (LCC, Lycopodiaceae) growing in Turkey. Anticholinesterase effect of the extracts was tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at concentrations of 0.2 and 1 mg mL(-1) using microplate-reader assay based on Ellman method. Antioxidant activity of the LCC extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging method at 0.2 mg mL(-1) using microplate-reader assay. Both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza (PI-3) were employed for antiviral assessment of LCC exracts using Madin-Darby Bovine Kidney and Vero cell lines. Antibacterial and antifungal activities of the extracts were screened against the bacteria: Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Acinobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis as well as the fungi: Candida albicans and C. parapsilosis. Only the petroleum ether extract of LCC possessed remarkable activity against both AChE and BChE at 1 mg mL(-1) (76.5 and 69.6%, respectively), whereas LCC extracts showed low free radical-scavenging activity. All of the extracts were found to be more effective against the ATCC strains than isolated ones, particularly S. aureus, while the extracts had moderate antifungal activity. On the other hand, we found that only the petroleum ether extract was active against HSV. In addition, we also analysed the content of the alkaloid fraction of the plant by capillary gas chromatography-mass spectrometry (GC-MS) and identified lycopodine as the major alkaloid (60.8%).
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PMID:In vitro biological activity screening of Lycopodium complanatum L. ssp. chamaecyparissus (A. Br.) Doll. 1938 28

Ethno pharmacological approach has provided several leads to identify potential new drugs from plant sources, including those for memory disorders. Acetylcholinesterase inhibitors (AChEI) give a symptomatic relief to some of the clinical manifestations of the disease. The main objective of this study is to standardize the extract of Trigonella foenum graecum L with trigonelline by HPTLC method and determine the in vitro AChE inhibitory activity of Trigonella foenum graecum L and its constituents using galanthamine as a reference. Different concentrations of hydro alcoholic extract of Trigonella foenum graecum and trigonelline were subjected to HPTLC analysis using the mobile phase n propanol, methanol and water (4:1:2, v/v). The R(f) of trigonelline was found to be 0.43, and the correlation coefficient of 0.99 was indicative of good linear dependence of peak area on concentration. The concentration of trigonelline was found to be 13mgg(-1)w/w in the hydro alcoholic extract of Trigonella foenum graecum. The AChE inhibitory activity of crude fenugreek seed extracts, fractions and trigonelline was evaluated using Ellman's method in 96-well micro plate's assay and TLC bioassay detection. The ethyl acetate fraction of the alcohol extract (IC50 53.00 +/- 17.33microg/ml), and total alkaloid fraction (IC50 9.23+/-6.08microg/ml) showed potential AChE inhibition. Trigonelline showed IC50 233+/-0.12microM. Galanthamine was used as standard and it showed inhibition of acetyl cholinesterase with an IC50 value of 1.27+/-0.21microM.
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PMID:Acetylcholinesterase enzyme inhibitory potential of standardized extract of Trigonella foenum graecum L and its constituents. 1957 40


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