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)

Huperzine-A (Hup-A), a biologically potent, reversible acetylcholinesterase inhibitor for the treatment of Alzheimer disease (AD) in China, has very low blood concentration. In order to study the pharmacokinetics of newly developed Hup-A transdermal patches in animal, a rapid and sensitive ion-pair reverse-phase high performance liquid chromatography (RP-HPLC) method for the determination of Hup-A in beagle dog serum using mebendazole as internal standard has been developed and validated. The analyte and internal standard were extracted from serum using chloroform-isopropanol (95:5, v/v), analyzed on a C (18) column (5 microm, 150 mm x 4.6 mm i.d.) with a mobile phase consisting of methanol-water-glacial acetic acid (50:48.5:1.5, v/v/v), using sodium dodecylsulfonate as an ion-pair reagent, and detected with UV detector at 313 nm. The chromatographic run time was within 15 min. The assay was linear over the concentration range of 1-12 ng/ml and intra- and inter-day precision over this range was not more than 12.8%. The limit of quantification in serum was 1 ng/ml. The method was successfully applied to characterize the Hup-A concentration-time profiles and study the single and multiple doses phamacokinetics of Hup-A transdermal patches in beagle dogs. The pharmacokinetic study results showed that Hup-A patches has the characteristic of sustained or controlled drug release in vivo.
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PMID:Ion-pair reverse-phase high performance liquid chromatography method for determination of Huperzine-A in beagle dog serum. 1568 84

A biotinylated organophosphate could be useful for identifying proteins that react with organophosphorus toxicants (OP). FP-biotin, 10-(fluoroethoxyphosphinyl)-N-(biotinamidopentyl)decanamide, was synthesized and found to be stable in methanol and chloroform but less stable in water. Because acetylcholinesterase (AChE, EC 3.1.1.7) and butyrylcholinesterase (BChE, EC 3.1.1.8) are known to be sensitive targets of OP, their reactivity with FP-biotin was tested. The rate constant for reaction with human AChE was 1.8 x 10(7) M(-1) min(-1), and for human BChE, it was 1.6 x 10(8) M(-1) min(-1). A phosphorus stereoisomer, constituting about 50% of the FP-biotin preparation, appeared to be the reactive species. The binding affinity was estimated to be >85 nM for AChE and >5.8 nM for BChE. It was concluded that FP-biotin is a potent OP, well-suited for searching for new biomarkers of OP exposure.
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PMID:Reaction kinetics of biotinylated organophosphorus toxicant, FP-biotin, with human acetylcholinesterase and human butyrylcholinesterase. 1583 35

Haloxylines A (1) and B (2), new piperidine alkaloids, have been isolated from the chloroform soluble fraction of Haloxylon salicornicum and their structures elucidated by spectroscopic techniques including 2D-NMR. Both the compounds displayed antifungal and cholinesterase enzymes inhibitory potentials.
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PMID:Haloxylines A and B, antifungal and cholinesterase inhibiting piperidine alkaloids from Haloxylon salicornicum. 1586 32

Haloxysterols A-D (1-4), new C-24 alkylated sterols, have been isolated from the chloroform soluble fraction of Haloxylon recurvum, along with five known sterols 5-9, which are reported for the first time from this species. Their structures were determined by means of 1D- and 2D-NMR techniques. Compounds 1-9 inhibited cholinesterase enzymes in a concentration-dependent manner with K(i) values ranging between 0.85-25.5 and 1.0-19.0 microM against acetylcholinesterase (AChE; EC 3.1.1.7) and butyrylcholinesterase (BChE; EC 3.1.1.8) enzymes, respectively. Lineweaver-Burk, Dixon plots and their secondary replots indicated that compounds 1-9 are non-competitive inhibitors of both AChE and BChE enzymes.
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PMID:Isolation and cholinesterase-inhibition studies of sterols from Haloxylon recurvum. 1627 89

ZT-1 is a novel acetylcholinesterase (AChE) inhibitor. It is rapidly transformed to Huperzine A (Hup A) in vitro. A simple and rapid HPLC-UV method for the simultaneous determination of ZT-1 and its metabolite Hup A in plasma is described. The chromatographic separations were achieved on a C(18) ODS column (250 mm x 4.6 mm ID) using methanol-1 mmol/L ammonium acetate (70:30,v/v) as mobile phase. The flow rate was 0.7 mL/min, the detection wavelength was 313 nm and the column temperature was kept at 35 degrees C. Plasma samples were prepared as rapidly as possible and extracted immediately with 5 mL of chloroform:iso-propyl alcohol mixture (v/v, 9:1). The retention times of ZT-1 and Huperzine A (Hup A) were 18.7 and 14.4 min, respectively. The mean absolute recoveries of two analytes were >90%. Quantification limits were all 0.02 nmol/mL for ZT-1 and Hup A. This analytical method was reliable and convenient procedure that meets the criteria for the pharmacokinetic evaluation of ZT-1 on experimental animals.
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PMID:Simultaneous determination of ZT-1 and its metabolite Huperzine A in plasma by high-performance liquid chromatography with ultraviolet detection. 1628 4

The centipede Scolopendra subspinipes mutilans L. Koch ('Wugong'), the beetle Mylabris phalerata Pallas ('Ban mao') and the earthworm Pheretima aspergillum Chen ('DiLong') have a reputation in traditional Chinese medicine for reducing symptoms of central nervous system decline, including memory loss. A series of extracts of all three organisms was tested for acetylcholinesterase (AChE) inhibition and copper ion binding effects, the latter likely to reduce oxidative damage caused by excess copper. The beetle and centipede chloroform extracts showed the strongest AChE inhibitory effects (30.6% inhibition at 105 microg mL(-1) and 32.3% inhibition at 167 microg mL(-1), respectively) and, in the case of the centipede, this was traced to the unsaturated fatty acids present using bioassay-guided fractionation. Cantharidin from the beetle was shown to have AChE activity (31% inhibition at 1 muM, 0.196 microg mL(-1)), making it a major contributor to the activity of the beetle extract. The earthworm showed no AChE inhibitory activity. Since unsaturated fatty acids have not been previously reported to have AChE inhibitory activity, a series of related compounds was tested to determine structure-activity relationships. It was found that activity existed where there was a chain length of more than 16 C atoms with at least one unsaturated bond in the chain. The carboxylic acid group was also necessary for activity. The fatty acids present in the centipede also showed the ability to bind copper ions when tested using a novel thin layer chromatography method designed to detect copper-binding compounds. The activities reported give some support to the use of the beetle and centipede in traditional Chinese medicine for improving cognitive function.
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PMID:Relevant activities of extracts and constituents of animals used in traditional Chinese medicine for central nervous system effects associated with Alzheimer's disease. 1680 60

Prunus persica L. Batsch water extract (PPE) is a potent acetylcholinesterase (AChE) inhibitor screened for the treatment of Alzheimer's disease. The effects of oral administration of the PPE were examined with comparison of those of selective butyrylcholinesterase inhibitors of 9-amino-1,2,3,4-tetrahydroacridine hydrochloride (tacrine) and tetraidopropylpyrophosphoramide (iso-OMPA) and a selective AChE inhibitor, donepezil, on the cholinesterase activity in the brain and plasma of rats. After the sequential solvent fractionation of the methanol extract of P. persica L. Batsch, the highest inhibitory fraction was that of chloroform (75%). The concentration that was required for 50% enzyme inhibition (IC(50) value) was 5.6 microg/mL for the chloroform fraction. Oral administration of PPE or tacrine caused a dose-dependent inhibition of brain and plasma cholinesterase activities. The ID(50) values of these compounds for brain cholinesterase activity were 2.7 g/kg and 8.9 mg/kg, respectively. On the other hand, the ID(50) values for plasma cholinesterase activity were 18.6 g/kg and 27.5 mg/kg, respectively. Thus, the ratios of the ID(50) (plasma < brain) were 6.0 and 3.1, respectively. These results suggest that orally administered PPE satisfactorily penetrates into the brain and inhibits cholinesterase there and that PPE is a potent inhibitor of brain cholinesterase in comparison with plasma cholinesterase in vivo.
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PMID:Pharmacological characterization of orally active cholinesterase inhibitory activity of Prunus persica L. Batsch in rats. 1695 99

In vitro enzymes inhibition activities of the crude methanolic extract and various fractions of Colchicum luteum Baker (Liliaceae) including chloroform, ethyl acetate, n-butanol and aqueous were carried out against actylcholinesterase, butyrylcholinesterase, lipoxygenase and urease enzymes. A significant enzyme inhibition activity (89%) is shown by the crude methanolic extract and its fractions against lipoxygenase, while low to significant activity (32-75%) was evident against butyrylcholinesterase. The crude methanolic extract and its various fractions demonstrated low activity (29-61%) against acetylcholinesterase and no activity against urease.
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PMID:Inhibition activities of Colchicum luteum baker on lipoxygenase and other enzymes. 1705 79

In this study we have found that the crude extract of Psoraleae Fructus inhibited acetylcholinesterase activity in vitro and ameliorated impairment of the inhibitory avoidance response and of the water maze spatial performance caused by scopolamine in rats. Among all fractions, the chloroform fraction showed the best inhibitory effect on acetylcholinesterase activity and could reduce the scopolamine-induced inhibitory avoidance response impairment. Psoralen and isopsoralen, two major constituents of the chloroform fraction of Psoraleae Fructus identified by high performance liquid chromatography, also reduced the extent of the inhibitory avoidance response impairment. The results suggest that psoralen and isopsoralen are the major active ingredients of Psoraleae Fructus responsible for the progressive reversal of scopolamine-induced amnesia, whose effects are partially associated with inhibition of AchE activity and hence activation of the central cholinergic neuronal system.
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PMID:Psoralen and isopsoralen, two coumarins of Psoraleae Fructus, can alleviate scopolamine-induced amnesia in rats. 1731 85

The crude methanolic extract and various fractions of Andrachne cardifolia Muell, including chloroform, ethyl acetate and n-butanol fractions were subjected to in vitro enzyme inhibition activity against acetylcholinesterase, butyrylcholinesterase, lipoxygenase and urease enzymes. A significant enzyme inhibition activity (40-89%) was shown by the crude methanolic extract and its fractions against lipoxygenase, while low to significant activity (40-71%) against butyrylcholinesterase. The crude methanolic extract and its various fractions demonstrated poor to significant activity (25-73%) against acetylcholinesterase and no activity against urease.
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PMID:Enzyme inhibition activities of Andrachne cardifolia Muell. 1751 51


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