Displaying publications 1 - 20 of 34 in total

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  1. Tham LG, Perumal N, Syed MA, Shamaan NA, Shukor MY
    J Environ Biol, 2009 Jan;30(1):135-8.
    PMID: 20112875
    An inhibitive assay of insecticides using Acetylcholinesterase (AChE) from the local fish Clarias batrachus is reported. AChE was assayed according to the modified method of Ellman. Screening of insecticide and heavy metals showed that carbofuran and carbaryl strongly inhibited C. batrachus AChE. The inhibition concentration (IC) IC50 values (and the 95% confidence interval) for both carbofuran and carbaryl inhibition on C. batrachus AChE at 6.66 (5.97-7.52) and 130.00 (119.3-142.5) microg l(-1), respectively was within the IC50 range of Electrophorus electricus at 6.20 (6.03-6.39) and 133.01 (122.40-145.50) microg l(-1), respectively and were much lower than bovine AChE at 20.94 (19.53-22.58) and 418.80 (390.60-451.60) microg l(-1), respectively. The results showed that C. batrachus have the potential to be used as a cheaper and more readily available source of AChE than other more commercially available sources.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  2. Awang K, Chan G, Litaudon M, Ismail NH, Martin MT, Gueritte F
    Bioorg Med Chem, 2010 Nov 15;18(22):7873-7.
    PMID: 20943395 DOI: 10.1016/j.bmc.2010.09.044
    A significant acetylcholinesterase (AChE) inhibitory activity was observed for the hexane extract from the bark of Mesua elegans (Clusiaceae). Thus, the hexane extract was subjected to chemical investigation, which led to the isolation of nine 4-phenylcoumarins, in which three are new; mesuagenin A (1), mesuagenin C (3), mesuagenin D (4) and one new natural product; mesuagenin B (2). The structures of the isolated compounds were characterized by spectroscopic data interpretation, especially 1D and 2D NMR. Four compounds showed significant AChE inhibitory activity, with mesuagenin B (2) being the most potent (IC(50)=0.7μM).
    Matched MeSH terms: Acetylcholinesterase/chemistry*
  3. Suresh Kumar R, Ashraf Ali M, Osman H, Ismail R, Choon TS, Yoon YK, et al.
    Bioorg Med Chem Lett, 2011 Jul 1;21(13):3997-4000.
    PMID: 21621414 DOI: 10.1016/j.bmcl.2011.05.003
    Hexacyclic derivatives share vital pharmacological properties, considered useful in Alzheimer's disease. The aim of this study was synthesis and its evaluation for acetyl cholinesterase inhibitory activity of novel hexacyclic analogues. Compound 4f, showed potent inhibitory activity against acetyl cholinesterase enzyme with IC(50) 0.72 μmol/L.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  4. Ashraf Ali M, Ismail R, Choon TS, Kumar RS, Osman H, Arumugam N, et al.
    Bioorg Med Chem Lett, 2012 Jan 1;22(1):508-11.
    PMID: 22142546 DOI: 10.1016/j.bmcl.2011.10.087
    Pyrrolothiazolyloxindole analogues share vital pharmacological properties, considered useful in Alzheimer's disease (AD). The aim of this study was synthesis and evaluate pyralothiazolyloxindole analogues if possess acetyl cholinesterase (AChE) inhibitory activity. The easily accessible one-pot synthesis of these compounds resulted to be significantly less difficult and expensive than that of donepezil. Several compounds possess anti-cholinesterase activity in the order of micro and sub-micromolar. Particularly, compound was the most potent inhibitors of the series against acetyl cholinesterase enzyme with IC(50) 0.11μmol/L.
    Matched MeSH terms: Acetylcholinesterase/chemistry*
  5. Khan A, Ab Ghani S
    Biosens Bioelectron, 2012 Jan 15;31(1):433-8.
    PMID: 22154168 DOI: 10.1016/j.bios.2011.11.007
    The electrochemical biosensors based on poly(o-phenylenediamine) (PoPD) and acetylcholinesterase (AChE) and choline oxidase (ChO) enzymes were fabricated on carbon fibre (CF) substrate. The electropolymerized PoPD was used to reduce the interfering substances. The electrode assembly was completed by depositing functionalized carbon nano tubes (FCNTs) and Nafion (Naf). Amperometric detection of acetylcholine (ACh) and choline (Ch) were realized at an applied potential of +750 mV vs Ag/AgCl (saturated KCl). At pH 7.4, the final assembly, Naf-FCNTs/AChE-ChO((10:1))/PoPD/CF(Elip), was observed to have high sensitivity towards Ch (6.3±0.3 μA mM(-1)) and ACh (5.8±0.3 μA mM(-1)), linear range for Ch (K(M)=0.52±0.03 mM) and ACh (K(M)=0.59±0.07 mM), and for Ch the highest ascorbic acid blocking capacity (97.2±2 1mM AA). It had a response time of <5s and with 0.045 μM limit of detection. Studies on different ratio (ACh/Ch) revealed that 10:1, gave best overall response.
    Matched MeSH terms: Acetylcholinesterase/chemistry*
  6. Nasir MN, Abdullah J, Habsah M, Ghani RI, Rammes G
    Phytomedicine, 2012 Feb 15;19(3-4):311-6.
    PMID: 22112723 DOI: 10.1016/j.phymed.2011.10.004
    The asiatic acid, a triterpenoids isolated from Centella asiatica was used to delineate its inhibitory effect on acetylcholinesterase (AChE) properties, excitatory post synaptic potential (EPSP) and locomotor activity. This study is consistent with asiatic acid having an effect on AChE, a selective GABA(B) receptor agonist and no sedative effect on locomotor.
    Matched MeSH terms: Acetylcholinesterase/chemistry*
  7. Gwaram NS, Ali HM, Abdulla MA, Buckle MJ, Sukumaran SD, Chung LY, et al.
    Molecules, 2012 Feb 28;17(3):2408-27.
    PMID: 22374313 DOI: 10.3390/molecules17032408
    Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 μM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  8. Fadaeinasab M, Hadi AH, Kia Y, Basiri A, Murugaiyah V
    Molecules, 2013 Mar 25;18(4):3779-88.
    PMID: 23529036 DOI: 10.3390/molecules18043779
    Plants of the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders. Rauvolfia reflexa, a member of the family, has been used as an antidote for poisons and to treat malaria. The dichloromethane, ethanol and methanol extracts from the leaves of Rauvolfia reflexa showed potential acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, with IC50 values in the 8.49 to 52.23 g/mL range. Further cholinesterase inhibitory-guided isolation of these extracts afforded four bioactive compounds, namely: (E)-3-(3,4,5-trimethoxyphenyl)acrylic acid (1), (E)-methyl 3-(4-hydroxy-3,5-dimethoxyphenyl) acrylate (2), 17-methoxycarbonyl-14-heptadecaenyl-4-hydroxy-3-methoxycinnamate (3) and 1,2,3,4-tetrahydro-1-oxo-β-carboline (4). The isolated compounds showed moderate cholinesterase inhibitory activity compared to the reference standard, physostigmine. Compounds 1 and 2 showed the highest inhibitory activity against AChE (IC50 = 60.17 µM) and BChE (IC50 = 61.72 µM), respectively. Despite having similar molecular weight, compounds 1 and 2 were structurally different according to their chemical substitution patterns, leading to their different enzyme inhibition selectivity. Compound 2 was more selective against BChE, whereas compound 1 was a selective inhibitor of AChE. Molecular docking revealed that both compounds 1 and 2 were inserted, but not deeply into the active site of the cholinesterase enzymes.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  9. Basiri A, Murugaiyah V, Osman H, Kumar RS, Kia Y, Ali MA
    Bioorg Med Chem, 2013 Jun 1;21(11):3022-31.
    PMID: 23602518 DOI: 10.1016/j.bmc.2013.03.058
    A series of hitherto unreported pyrido-pyrimidine-2-ones/pyrimidine-2-thiones were synthesized under microwave assisted solvent free reaction conditions in excellent yields and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activity. Among the pyridopyrimidine derivatives, 7e and 7l displayed 2.5- and 1.5-fold higher enzyme inhibitory activities against AChE as compared to standard drug, galanthamine, with IC50 of 0.80 and 1.37 μM, respectively. Interestingly, all the compounds except 6k, 7j and 7k displayed higher inhibitory potential against BChE enzyme in comparison to standard with IC50 ranging from 1.18 to 18.90 μM. Molecular modeling simulations of 7e and 7l was performed using three-dimensional structure of Torpedo californica AChE (TcAChE) and human butyrylcholinesterase (hBChE) enzymes to disclose binding interaction and orientation of these molecule into the active site gorge of respective receptors.
    Matched MeSH terms: Acetylcholinesterase/chemistry*
  10. Ali Hassan SH, Abu Bakar MF
    ScientificWorldJournal, 2013;2013:278071.
    PMID: 24298210 DOI: 10.1155/2013/278071
    Cyphomandra betacea is one of the underutilized fruits which can be found in tropical and subtropical countries. This study was conducted to determine the antioxidant activity and phytochemical contents in different parts (i.e., flesh and peel) of the fruits. Antioxidants were analyzed using DPPH and ABTS free radical scavenging assays as well as FRAP assay. Anticholinesterase activity was determined using enzymatic assay using acetyl cholinesterase enzyme. For 80% methanol extract, the peel of the fruit displayed higher antioxidant activity in both FRAP and ABTS free radical scavenging assays while the flesh displayed higher antioxidant activity in the DPPH assay. Total phenolic and total flavonoid content were higher in the peel with the values of 4.89 ± 0.04 mg gallic acid equivalent (GAE)/g and 3.36 ± 0.01 mg rutin equivalent (RU)/g, respectively. Total anthocyanin and carotenoid content were higher in the flesh of the fruit with the values of 4.15 ± 0.04 mg/100 g and 25.13 ± 0.35 mg/100 g. The anticholinesterase was also higher in the peel of C. betacea. The same trends of phytochemicals, antioxidant, and anticholinesterase were also observed in the distilled water extracts. These findings suggested that C. betacea has a potential as natural antioxidant-rich nutraceutical products.
    Matched MeSH terms: Acetylcholinesterase/chemistry*
  11. Yusoff M, Hamid H, Houghton P
    Molecules, 2014 Jan 20;19(1):1201-11.
    PMID: 24448061 DOI: 10.3390/molecules19011201
    Quaternary alkaloids are the major alkaloids isolated from Tinospora species. A previous study pointed to the necessary presence of quaternary nitrogens for strong acetylcholinesterase (AChE) inhibitory activity in such alkaloids. Repeated column chromatography of the vine of Tinospora crispa extract led to the isolation of one new protoberberine alkaloid, 4,13-dihydroxy-2,8,9-trimethoxydibenzo[a,g]quinolizinium (1), along with six known alkaloids-dihydrodiscretamine (2), columbamine (3), magnoflorine (4), N-formylannonaine (5), N-formylnornuciferine (6), and N-trans-feruloyltyramine (7). The seven compounds were isolated and structurally elucidated by spectroscopic analysis. Two known alkaloids, namely, dihydrodiscretamine and columbamine are reported for the first time for this plant. The compounds were tested for AChE inhibitory activity using Ellman's method. In the AChE inhibition assay, only columbamine (3) showed strong activity with IC50 48.1 µM. The structure-activity relationships derived from these results suggest that the quaternary nitrogen in the skeleton has some effect, but that a high degree of methoxylation is more important for acetylcholinesterase inhibition.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  12. Kia Y, Osman H, Kumar RS, Basiri A, Murugaiyah V
    Bioorg Med Chem, 2014 Feb 15;22(4):1318-28.
    PMID: 24461561 DOI: 10.1016/j.bmc.2014.01.002
    One pot, three-component reaction of 1-acryloyl-3,5-bisarylmethylidenepiperidin-4-ones with isatin and sarcosine in molar ratios of 1:1:1 and 1:2:2 furnished to mono- and bis-spiropyrrolidine heterocyclic hybrids comprising functionalized piperidine, pyrrolidine and oxindole structural motifs. Both mono and bis-spiropyrrolidines displayed good inhibitory activity against acetylcholinesterase (AChE) with IC₅₀ values of 2.36-9.43 μM. For butyrylcholinesterase (BChE), mono-cycloadducts in series 8 with IC₅₀ values of lower than 10 μM displayed better inhibitory activities than their bis-cycloadduct analogs in series 9 with IC₅₀ values of 7.44-19.12 μM. The cycloadducts 9j and 8e were found to be the most potent AChE and BChE inhibitors with IC₅₀ values of 2.35 and 3.21 μM, respectively. Compound 9j was found to be competitive inhibitor of AChE while compound 8e was a mixed-mode inhibitor of BChE with calculated Ki values of 2.01 and 6.76 μM, respectively. Molecular docking on Torpedo californica AChE and human BChE showed good correlation between IC₅₀ values and free binding energy values of the synthesized compounds docked into the active site of the enzymes.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  13. Bukhari SN, Jantan I, Masand VH, Mahajan DT, Sher M, Naeem-ul-Hassan M, et al.
    Eur J Med Chem, 2014 Aug 18;83:355-65.
    PMID: 24980117 DOI: 10.1016/j.ejmech.2014.06.034
    A series of novel carbonyl compounds was synthesized by a simple, eco-friendly and efficient method. These compounds were screened for anti-oxidant activity, in vitro cytotoxicity and for inhibitory activity for acetylcholinesterase and butyrylcholinesterase. The effect of these compounds against amyloid β-induced cytotoxicity was also investigated. Among them, compound 14 exhibited strong free radical scavenging activity (18.39 μM) while six compounds (1, 3, 4, 13, 14, and 19) were found to be the most protective against Aβ-induced neuronal cell death in PC12 cells. Compounds 4 and 14, containing N-methyl-4-piperidone linker, showed high acetylcholinesterase inhibitory activity as compared to reference drug donepezil. Molecular docking and QSAR (Quantitative Structure-Activity Relationship) studies were also carried out to determine the structural features that are responsible for the acetylcholinesterase and butyrylcholinesterase inhibitory activity.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  14. Abd Razik BM, Osman H, Basiri A, Salhin A, Kia Y, Ezzat MO, et al.
    Bioorg Chem, 2014 Dec;57:162-168.
    PMID: 25462993 DOI: 10.1016/j.bioorg.2014.10.005
    Novel aromatic embedded Schiff bases have been synthesized in ionic liquid [bmim]Br and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activities. Among the newly synthesized compounds, 5f, 5h and 7j displayed higher AChE enzyme inhibitory activities than standard drug, galanthamine, with IC50 values of 1.88, 2.05 and 2.03μM, respectively. Interestingly, all the compounds except for compound 5c displayed higher BChE inhibitories than standard with IC50 values ranging from 3.49 to 19.86μM. Molecular docking analysis for 5f and 7j possessing the most potent AChE and BChE inhibitory activities, disclosed their binding interaction templates to the active site of AChE and BChE enzymes, respectively.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  15. Kia Y, Osman H, Kumar RS, Murugaiyah V, Basiri A, Khaw KY, et al.
    Med Chem, 2014;10(5):512-20.
    PMID: 24138113
    A series of hitherto unreported piperidone embedded α,β-unsaturated ketones were synthesized efficiently in ionic solvent and evaluated for cholinesterase inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Most of the synthesized compounds displayed good enzyme inhibition; therein compounds 7i and 7f displayed significant activity against AChE with IC50 values of 1.47 and 1.74 µM, respectively. Compound 6g showed the highest BChE inhibitory potency with IC50 value of 3.41 µM, being 5 times more potent than galanthamine. Molecular modeling simulation was performed using AChE and BChE receptors extracted from crystal structure of human AChE and human BChE to determine the amino acid residues involved in the binding interaction of synthesized compounds and their relevant receptors.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  16. Almansour AI, Kumar RS, Arumugam N, Basiri A, Kia Y, Ali MA, et al.
    Molecules, 2015 Jan 29;20(2):2296-309.
    PMID: 25642838 DOI: 10.3390/molecules20022296
    A series of novel dimethoxyindanone embedded spiropyrrolidines were synthesized in ionic liquid, [bmim]Br and were evaluated for their inhibitory activities towards cholinesterases. Among the spiropyrrolidines, compound 4f exhibited the most potent activity with an IC50 value of 1.57 µM against acethylcholinesterase (AChE). Molecular docking simulation for the most active compound was employed with the aim of disclosing its binding mechanism to the active site of AChE receptor.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  17. Liew KF, Chan KL, Lee CY
    Eur J Med Chem, 2015 Apr 13;94:195-210.
    PMID: 25768702 DOI: 10.1016/j.ejmech.2015.02.055
    A series of novel aurones bearing amine and carbamate functionalities at various positions (rings A and/or B) of the scaffold was synthesized and evaluated for their acetylcholinesterase and butyrylcholinesterase inhibitory activities. Structure-activity relationship study disclosed several potent submicromolar acetylcholinesterase inhibitors (AChEIs) particularly aurones bearing piperidine and pyrrolidine moieties at ring A or ring B. Bulky groups particularly methoxyls, and carbamate to a lesser extent, at either rings were also prominently featured in these AChEI aurones as exemplified by the trimethoxyaurone 4-3. The active aurones exhibited a lower butyrylcholinesterase inhibition. A 3'-chloroaurone 6-3 originally designed to improve the metabolic stability of the scaffold was the most potent of the series. Molecular docking simulations showed these AChEI aurones to adopt favourable binding modes within the active site gorge of the Torpedo californica AChE (TcAChE) including an unusual chlorine-π interaction by the chlorine of 6-3 to establish additional bondings to hydrophobic residues of TcAChE. Evaluation of the potent aurones for their blood-brain barrier (BBB) permeability and metabolic stability using PAMPA-BBB assay and in vitro rat liver microsomes (RLM) identified 4-3 as an aurone with an optimal combination of high passive BBB permeability and moderate CYP450 metabolic stability. LC-MS identification of a mono-hydroxylated metabolite found in the RLM incubation of 4-3 provided an impetus for further improvement of the compound. Thus, 4-3, discovered within this present series is a promising, drug-like lead for the development of the aurones as potential multipotent agents for Alzheimer's disease.
    Matched MeSH terms: Acetylcholinesterase/chemistry
  18. Almansour AI, Kumar RS, Arumugam N, Basiri A, Kia Y, Ali MA
    Biomed Res Int, 2015;2015:965987.
    PMID: 25710037 DOI: 10.1155/2015/965987
    A series of hexahydro-1,6-naphthyridines were synthesized in good yields by the reaction of 3,5-bis[(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones with cyanoacetamide in the presence of sodium ethoxide under simple mixing at ambient temperature for 6-10 minutes and were assayed for their acetylcholinesterase (AChE) inhibitory activity using colorimetric Ellman's method. Compound 4e with methoxy substituent at ortho-position of the phenyl rings displayed the maximum inhibitory activity with IC50 value of 2.12 μM. Molecular modeling simulation of 4e was performed using three-dimensional structure of Torpedo californica AChE (TcAChE) enzyme to disclose binding interaction and orientation of this molecule into the active site gorge of the receptor.
    Matched MeSH terms: Acetylcholinesterase/chemistry*
  19. Razik BM, Osman H, Ezzat MO, Basiri A, Salhin A, Kia Y, et al.
    Med Chem, 2016;12(6):527-36.
    PMID: 26833077
    BACKGROUND: The search for new cholinesterase inhibitors is still a promising approach for management of Alzheimer`s disease. Schiff bases are considered as important class of organic compounds, which have wide range of applications including as enzyme inhibitors. In the present study, a new green ionic liquid mediated strategy was developed for convenient synthesis of two series of Schiff bases 3(a-j) and 5(a-j) as potential cholinesterase inhibitors using aromatic aldehydes and primary amines in [bmim]Br.

    METHODS: The synthesized compounds were evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential by modified Ellman's method. The molecular interactions between the most active compound and the enzyme were analyzed by molecular docking.

    RESULTS: Among them, 3j displayed higher inhibitory activities than reference drug, galanthamine, with IC50 values of 2.05 and 5.77 µM, for AChE and BChE, respectively. Interestingly, all the compounds except 3b displayed higher BChE inhibitions than galanthamine with IC50 values ranging from 5.77 to 18.52 µM. Molecular docking of compound 3j inside the TcAChE and hBChE completely coincided with the inhibitory activities observed. The compound forms strong hydrogen bonding at the peripheral anionic site of AChE whereas on BChE, it had hydrophobic and mild polar interactions.

    CONCLUSION: An efficient and eco-friendly synthetic methodology has been developed to synthesize Schiff bases in a very short reaction time and excellent yields in ionic solvent, whereby the compounds from series 3 showed promising cholinesterase inhibitory activity.

    Matched MeSH terms: Acetylcholinesterase/chemistry
  20. Yeong KY, Liew WL, Murugaiyah V, Ang CW, Osman H, Tan SC
    Bioorg Chem, 2017 02;70:27-33.
    PMID: 27863748 DOI: 10.1016/j.bioorg.2016.11.005
    A series of novel cholinesterase inhibitors containing nitrobenzoate core structure were synthesized by a facile and efficient method. The structure of the novel compounds were fully characterized and confirmed by analytical as well as spectroscopic methods. Compound indicated as 2f was found to possess the best cholinesterase inhibitory activities of all the evaluated compounds. Results suggest that 2f is a selective acetylcholinesterase inhibitor, although it also inhibits butyrylcholinesterase at higher concentration. Kinetics inhibition result suggest that 2f is a mixed-mode inhibitor of acetylcholinesterase. In addition, it was found to have low cytotoxicity. Molecular docking on compound 2f was carried out to rationalize the observed in vitro enzymatic assay results. Most importantly, the potential of nitrobenzoate derivatives as cholinesterase inhibitor was shown through this study. In summary, we discovered nitrobenzoates as a new scaffold that may eventually yield useful compounds in treatment of Alzheimer's disease.
    Matched MeSH terms: Acetylcholinesterase/chemistry
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