Displaying publications 1 - 20 of 24 in total

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  1. Khan KM, Saad SM, Shaikh NN, Hussain S, Fakhri MI, Perveen S, et al.
    Bioorg Med Chem, 2014 Jul 1;22(13):3449-54.
    PMID: 24844756 DOI: 10.1016/j.bmc.2014.04.039
    2-Arylquinazolin-4(3H)-ones 1-25 were synthesized by reacting anthranilamide with various benzaldehydes using CuCl2·2H2O as a catalyst in ethanol under reflux. Synthetic 2-arylquinazolin-4(3H)-ones 1-25 were evaluated for their β-glucuronidase inhibitory potential. A trend of inhibition IC50 against the enzyme in the range of 0.6-198.2μM, was observed and compared with the standard d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Compounds 13, 19, 4, 12, 14, 22, 23, 25, 15, 8, 17, 11, 21, 1, 3, 18, 9, 2, and 24 with the IC50 values within the range of 0.6-44.0μM, indicated that the compounds have superior activity than the standard. The compounds showed no cytotoxic effects against PC-3 cells. A structure-activity relationship is established.
  2. Khan KM, Naz F, Taha M, Khan A, Perveen S, Choudhary MI, et al.
    Eur J Med Chem, 2014 Mar 3;74:314-23.
    PMID: 24486414 DOI: 10.1016/j.ejmech.2014.01.001
    Thiourea derivatives (1-38) were synthesized and evaluated for their urease inhibition potential. The synthetic compounds showed a varying degree of in vitro urease inhibition with IC50 values 5.53 ± 0.02-91.50 ± 0.08 μM, most of which are superior to the standard thiourea (IC₅₀ = 21.00 ± 0.11 μM). In order to ensure the mode of inhibition of these compounds, the kinetic study of the most active compounds has been carried out. Most of these inhibitors were found to be mixed-type of inhibitors, except compounds 13 and 30 which were competitive, while compound 19 was identified as non-competitive inhibitor with Ki values between 8.6 and 19.29 μM.
  3. Choudhary MI, Ismail M, Shaari K, Abbaskhan A, Sattar SA, Lajis NH, et al.
    J Nat Prod, 2010 Apr 23;73(4):541-7.
    PMID: 20356064 DOI: 10.1021/np900551u
    Phytochemical and cytotoxicity investigations on organic solvent extracts of the aerial parts of Tinospora crispa have led to the isolation of 15 cis-clerodane-type furanoditerpenoids. Of these, nine compounds (1-9) were found to be new. Spectroscopic assignments of a previously reported compound, borapetoside A (13), were revised on the basis of HMQC and HMBC correlations. No discernible activity was observed when compounds 10-13 were subjected to evaluation in cytotoxicity assays against human prostate cancer (PC-3) and the normal mouse fibroblast (3T3) cell lines.
  4. Ghayur MN, Gilani AH, Khan A, Amor EC, Villaseñor IM, Choudhary MI
    Phytother Res, 2006 Jan;20(1):49-52.
    PMID: 16397921
    Syzygium samarangense (Family; Myrtaceae) or 'makopa', as it is commonly known, is native to Malaysia, some islands of Indonesia and to Far East in general. This study was undertaken to rationalize the use of this plant in hypermotility states of the gut. The hexane extract of S. samarangense (Ss.Hex) was found to dose-dependently (10-3000 microg/mL) relax the spontaneously contracting isolated rabbit jejunum. When tested for a possible calcium channel blocking (CCB) activity, the extract (10-1000 microg/mL) relaxed the high K+-induced contractions and also decreased the Ca++ dose-response curves in a dose-dependent manner (30-100 microg/mL), confirming the CCB activity. Four flavonoids isolated from the hexane extract were tested for a possible spasmolytic activity. All flavonoids, identified as: 2'-hydroxy-4',6'-dimethoxy-3'-methylchalcone (SS1), 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (SS2), 2',4'-dihydroxy-6'-methoxy-3'-methylchalcone (SS3) and 7-hydroxy-5-methoxy-6,8-dimethylflavanone (SS4), showed dose-dependent (10-1000 microg/mL) spasmolytic activity with SS2 being the most potent. These results indicate that the presence of compounds with spasmolytic and calcium antagonist activity may be responsible for the medicinal use of the plant in diarrhoea.
  5. Koko WS, Mesaik MA, Ranjitt R, Galal M, Choudhary MI
    PMID: 26553149 DOI: 10.1186/s12906-015-0931-x
    Hydnora abyssinica (HA) A. Braun is an endemic Sudanese medicinal plant traditionally used as anti-inflammatory and against many infectious diseases. However, it proved to be very rich in phenols and tannins, so the present study was undertaken to investigate the immunomodulatory potential of the whole plant ethanolic extract and its isolated compounds.
  6. Zahari A, Ablat A, Sivasothy Y, Mohamad J, Choudhary MI, Awang K
    Asian Pac J Trop Med, 2016 Apr;9(4):328-332.
    PMID: 27086149 DOI: 10.1016/j.apjtm.2016.03.008
    OBJECTIVE: To study antiplasmodial and antioxidant activities of the isolation of alkaloids from the active dichloromethane extract of Alseodaphne corneri.

    METHODS: Phytochemical studies of the crude extract led to the isolation of six alkaloids using recycle high performance liquid chromatography and preparative thin layer chromatography. The antiplasmodial activity of the isolated compounds was evaluated using the histidine-rich protein II assay. The isolated alkaloids were also tested for their antioxidant activity using three different assays; DPPH, ferric reducing ability of plasma and metal chelating assays.

    RESULTS: Malaria infection caused the formation of free radicals which subsequently led to oxidative stress and apoptosis. The antioxidant properties of the alkaloids under investigation revealed that in addition to the antiplasmodial activity, the alkaloids could also prevent oxidative stress. (+)-laurotetanine and (+)-norstephasubine exhibited strong antiplasmodial activities with IC50 values of 0.189 and 0.116 μM, respectively.

    CONCLUSIONS: Interestingly, the two most potent compounds that exhibit antiplasmodial activity also exhibit good antioxidant activities. The crude dichloromethane extract and the isolated compounds exert substantial antiplasmodial and antioxidative activities which in turn suppress oxidative stress and cause less damage to the host.

  7. Imran S, Taha M, Ismail NH, Fayyaz S, Khan KM, Choudhary MI
    Bioorg Chem, 2015 Oct;62:83-93.
    PMID: 26275866 DOI: 10.1016/j.bioorg.2015.08.001
    This article describes discovery of 29 novel bisindolylmethanes consisting of thiourea moiety, which had been synthesized through three steps. These novel bisindolylmethane derivatives evaluated for their potential inhibitory activity against carbonic anhydrase (CA) II. The results for in vitro assay of carbonic anhydrase II inhibition activity showed that some of the compounds are capable of suppressing the activity of carbonic anhydrase II. Bisindoles having halogen at fifth position showed better inhibitory activity as compared to unsubstituted bisindoles. Derivatives showing inhibition activity docked to further, understand the binding behavior of these compounds with carbonic anhydrase II. Docking studies for the active compound 3j showed that nitro substituent at para position fits into the core of the active site. The nitro substituent of compound 3j is capable of interacting with Zn ion. This interaction believed to be the main factor causing inhibition activity to take place.
  8. Ikram R, Mohamed Jan B, Vejpravova J, Choudhary MI, Zaman Chowdhury Z
    Nanomaterials (Basel), 2020 Oct 11;10(10).
    PMID: 33050617 DOI: 10.3390/nano10102004
    Nanocomposite materials have distinctive potential for various types of captivating usage in drilling fluids as a well-designed solution for the petroleum industry. Owing to the improvement of drilling fluids, it is of great importance to fabricate unique nanocomposites and advance their functionalities for amplification in base fluids. There is a rising interest in assembling nanocomposites for the progress of rheological and filtration properties. A series of drilling fluid formulations have been reported for graphene-derived nanocomposites as additives. Over the years, the emergence of these graphene-derived nanocomposites has been employed as a paradigm to formulate water-based drilling fluids (WBDF). Herein, we provide an overview of nanocomposites evolution as engineered materials for enhanced rheological attributes in drilling operations. We also demonstrate the state-of-the-art potential graphene-derived nanocomposites for enriched rheology and other significant properties in WBDF. This review could conceivably deliver the inspiration and pathways to produce novel fabrication of nanocomposites and the production of other graphenaceous materials grafted nanocomposites for the variety of drilling fluids.
  9. Taha M, Baharudin MS, Ismail NH, Khan KM, Jaafar FM, Samreen, et al.
    Bioorg Med Chem Lett, 2013 Jun 1;23(11):3463-6.
    PMID: 23608761 DOI: 10.1016/j.bmcl.2013.03.051
    Compounds 1-25 showed varying degree of antileishmanial activities with IC50 values ranging between 1.95 and 88.56 μM. Compounds 2, 10, and 11 (IC50=3.29±0.07 μM, 1.95±0.04 μM, and 2.49±0.03 μM, respectively) were found to be more active than standard pentamidine (IC50=5.09±0.04 μM). Compounds 7 (IC50=7.64±0.1 μM), 8 (IC50=13.17±0.46 μM), 18 (IC50=13.15±0.02 μM), and 24 (IC50=15.65±0.41 μM) exhibited good activities. Compounds 1, 3, 4, 5, 9, 12, 15, 18, and 19 were found to be moderately active. Compounds 13, 14, 16, 17, 20-25 showed weak activities with IC50 values ranging between 57 and 88 μM.
  10. Imran S, Taha M, Ismail NH, Fayyaz S, Khan KM, Choudhary MI
    Bioorg Chem, 2016 10;68:90-104.
    PMID: 27474804 DOI: 10.1016/j.bioorg.2016.07.011
    In this study, 45 bisindolylmethanes having sulfonamide moiety had been synthesized through 3 steps. In vitro assay for inhibition of carbonic anhydrase showed that some of the compounds having sulfonamide moiety are capable of inhibiting carbonic anhydrase II. Bisindoles having halogens at fifth position showed better inhibitory activity as compared to unsubstituted bisindoles. The results obtained from in vitro inhibitory activity were subjected through 3D QSAR and docking studies to identify important features contributing to the activity and further improve the structure. Pharmacophore studies suggest that bisindolylmethane moiety is contributing significantly towards the inhibition activity. Docking studies showed that compounds having nitro substituent (5g and 5i) were found to be able interact with Zn(2+) ion, Thr199, His94, His96, and His119, which interferes with the ZnOHThr199Glu106 hydrogen bond network. Bulky nitro substituent at ortho position for compound 5g prevents the compound from interacting with other residues like Thr199 and Thr200. Methyl substituent at ortho position for Compound 5i induces less steric hindrance effect, thus allowing second oxygen atom of sulfonamide to interact with Thr199 (2.51Å). Hydrogen bonding between NH on indole ring with Glu69 might have increased stability of ligand-receptor complex.
  11. Iqbal S, Saleem M, Azim MK, Taha M, Salar U, Khan KM, et al.
    Bioorg Chem, 2017 06;72:89-101.
    PMID: 28390994 DOI: 10.1016/j.bioorg.2017.03.014
    Discovery and development of carbonic anhydrase inhibitors is crucial for their clinical use as antiepileptic, diurectic and antiglaucoma agents. Keeping this in mind, we have synthesized carbohydrazones 1-27 and evaluated them for their in vitro carbonic anhydrase inhibitory potential. Out of twenty-seven compounds, compounds 1 (IC50=1.33±0.01µM), 2 (IC50=1.85±0.24µM), 3 (IC50=1.37±0.06µM), and 9 (IC50=1.46±0.12µM) have showed carbonic anhydrase inhibition better than the standard drug zonisamide (IC50=1.86±0.03µM). Moreover, compounds 4 (IC50=2.32±0.04µM), 5 (IC50=3.96±0.35µM), 7 (IC50=2.33±0.02µM), and 8 (IC50=2.67±0.01µM) showed good inhibitory activity. Cheminformatic analysis has shown that compounds 1 and 2 possess lead-like properties. In addition, kinetic and molecular docking studies were also performed to investigate the binding interaction between carbohydrazones and carbonic anhydrase enzyme. This study has identified a novel and potent class of carbonic anhydrase inhibitors with the potential to be investigated further.
  12. Taha M, Naz H, Rasheed S, Ismail NH, Rahman AA, Yousuf S, et al.
    Molecules, 2014 Jan 21;19(1):1286-301.
    PMID: 24451249 DOI: 10.3390/molecules19011286
    A series of 4-methoxybenzoylhydrazones 1-30 was synthesized and the structures of the synthetic derivatives elucidated by spectroscopic methods. The compounds showed a varying degree of antiglycation activity, with IC50 values ranging between 216.52 and 748.71 µM, when compared to a rutin standard (IC50=294.46±1.50 µM). Compounds 1 (IC50=216.52±4.2 µM), 3 (IC50=289.58±2.64 µM), 6 (IC50=227.75±0.53 µM), 7 (IC50=242.53±6.1) and 11 (IC50=287.79±1.59) all showed more activity that the standard, and these compounds have the potential to serve as possible leads for drugs to inhibit protein glycation in diabetic patients. A preliminary SAR study was performed.
  13. Taha M, Ismail NH, Lalani S, Fatmi MQ, Atia-Tul-Wahab, Siddiqui S, et al.
    Eur J Med Chem, 2015 Mar 6;92:387-400.
    PMID: 25585009 DOI: 10.1016/j.ejmech.2015.01.009
    In an effort to design and synthesize a new class of α-glucosidase inhibitor, we synthesized benzothiazole hybrid having benzohydrazide moiety (5). Compound 5 was reacted with various substituted aryl aldehyde to generate a small library of compounds 6-35. Synthesis of compounds was confirmed by the spectral information. These compounds were screened for their α-glucosidase activity. They showed a varying degree of α-glucosidase inhibition with IC50 values ranging between 5.31 and 53.34 μM. Compounds 6, 7, 9-16, 19, 21-30, 32-35 showed superior activity as compared to standard acarbose (IC50 = 906 ± 6.3 μM). This has identified a new class of α-glucosidase inhibitors. The predicted physico-chemical properties indicated the drug appropriateness for most of these compounds, as they obey Lipinski's rule of five (RO5). A hybrid B3LYP density functional theory (DFT) was employed for energy, minimization of 3D structures for all synthetic compounds using 6-311 + G(d,p) basis sets followed by molecular docking to explore their interactions with human intestinal C- and N-terminal domains of α-glucosidase. All compounds bind to the prospective allosteric site of the C- terminal domain, and consequently, may be considered as mixed inhibitors. It was hypothesized that both the dipole moment and H-bond interactions govern the biological activation of these compounds.
  14. Jamil W, Perveen S, Shah SA, Taha M, Ismail NH, Perveen S, et al.
    Molecules, 2014 Jun 25;19(7):8788-802.
    PMID: 24968334 DOI: 10.3390/molecules19078788
    Phenoxyacetohydrazide Schiff base analogs 1-28 have been synthesized and their in vitro β-glucouoronidase inhibition potential studied. Compounds 1 (IC50=9.20±0.32 µM), 5 (IC50=9.47±0.16 µM), 7 (IC50=14.7±0.19 µM), 8 (IC50=15.4±1.56 µM), 11 (IC50=19.6±0.62 µM), 12 (IC50=30.7±1.49 µM), 15 (IC50=12.0±0.16 µM), 21 (IC50=13.7±0.40 µM) and 22 (IC50=22.0±0.14 µM) showed promising β-glucuronidase inhibition activity, better than the standard (D-saccharic acid-1,4-lactone, IC50=48.4±1.25 µM).
  15. Khan KM, Rahim F, Khan A, Shabeer M, Hussain S, Rehman W, et al.
    Bioorg Med Chem, 2014 Aug 1;22(15):4119-23.
    PMID: 24986232 DOI: 10.1016/j.bmc.2014.05.057
    A series of thiobarbituric acid derivatives 1-27 were synthesized and evaluated for their urease inhibitory potential. Exciting results were obtained from the screening of these compounds 1-27. Compounds 5, 7, 8, 11, 16, 17, 22, 23 and 24 showed excellent urease inhibition with IC50 values 18.1 ± 0.52, 16.0 ± 0.45, 16.0 ± 0.22, 14.3 ± 0.27, 6.7 ± 0.27, 10.6 ± 0.17, 19.2 ± 0.29, 18.2 ± 0.76 and 1.61 ± 0.18 μM, respectively, much better than the standard urease inhibitor thiourea (IC₅₀=21 ± 0.11 μM). Compound 3, 4, 10, and 26 exhibited comparable activities to the standard with IC₅₀ values 21.4 ± 1.04 and 21.5 ± 0.61 μM, 22.8 ± 0.32, 25.2 ± 0.63, respectively. However the remaining compounds also showed prominent inhibitory potential The structure-activity relationship was established for these compounds. This study identified a novel class of urease inhibitors. The structures of all compounds were confirmed through spectroscopic techniques such as EI-MS and (1)H NMR.
  16. Barakat A, Islam MS, Al-Majid AM, Ghabbour HA, Fun HK, Javed K, et al.
    Bioorg Med Chem, 2015 Oct 15;23(20):6740-8.
    PMID: 26381063 DOI: 10.1016/j.bmc.2015.09.001
    We describe here the synthesis of dihydropyrimidines derivatives 3a-p, and evaluation of their α-glucosidase enzyme inhibition activities. Compounds 3b (IC50=62.4±1.5 μM), 3c (IC50=25.3±1.26 μM), 3d (IC50=12.4±0.15 μM), 3e (IC50=22.9±0.25 μM), 3g (IC50=23.8±0.17 μM), 3h (IC50=163.3±5.1 μM), 3i (IC50=30.6±0.6 μM), 3m (IC50=26.4±0.34 μM), and 3o (IC50=136.1±6.63 μM) were found to be potent α-glucosidase inhibitors in comparison to the standard drug acarbose (IC50=840±1.73 μM). The compounds were also evaluated for their in vitro cytotoxic activity against PC-3, HeLa, and MCF-3 cancer cell lines, and 3T3 mouse fibroblast cell line. All compounds were found to be non cytotoxic, except compounds 3f and 3m (IC50=17.79±0.66-20.44±0.30 μM), which showed a weak cytotoxic activity against the HeLa, and 3T3 cell lines. In molecular docking simulation study, all the compounds were docked into the active site of the predicted homology model of α-glucosidase enzyme. From the docking result, it was observed that most of the synthesized compounds showed interaction through carbonyl oxygen atom and polar phenyl ring with active site residues of the enzyme.
  17. Maher S, Choudhary MI, Saleem F, Rasheed S, Waheed I, Halim SA, et al.
    Biology (Basel), 2020 Jul 30;9(8).
    PMID: 32751610 DOI: 10.3390/biology9080197
    Withania coagulans (W. coagulans) is well-known in herbal medicinal systems for its high biological potential. Different parts of the plant are used against insomnia, liver complications, asthma, and biliousness, as well as it is reported to be sedative, emetic, diuretic, antidiabetic antimicrobial, anti-inflammatory, antitumor, hepatoprotective, antihyperglycemic, cardiovascular, immuno-suppressive and central nervous system depressant. Withanolides present in W. coagulans have attracted an immense interest in the scientific field due to their diverse therapeutic applications. The current study deals with chemical and biological evaluation of chloroform, and n-butanol fractions of W. coagulans. The activity-guided fractionation of both extracts via multiple chromatographic steps and structure elucidation of pure isolates using spectroscopies (NMR, mass spectrometry, FTIR and UV-Vis) led to the identification of a new withanolide glycoside, withacogulanoside-B (1) from n-butanol extract and five known withanolides from chloroform extract [withanolid J (2), coagulin E (3), withaperuvin C (4), 27-hydroxywithanolide I (5), and ajugin E (6)]. Among the tested compounds, compound 5 was the most potent α-glucosidase inhibitor with IC50 = 66.7 ± 3.6 µM, followed by compound 4 (IC50: 407 ± 4.5 µM) and compound 2 (IC50: 683 ± 0.94 µM), while no antiglycation activity was observed with the six isolated compounds. Molecular docking was used to predict the binding potential and binding site interactions of these compounds as α-glucosidase inhibitors. Consequently, this study provides basis to discover specific antidiabetic compounds from W. coagulans.
  18. Zawawi NK, Rajput SA, Taha M, Ahmat N, Ismail NH, Abdullah N, et al.
    Bioorg Med Chem Lett, 2015 Oct 15;25(20):4672-6.
    PMID: 26330080 DOI: 10.1016/j.bmcl.2015.08.022
    Apoptotic cell death is the cause of the loss of insulin-producing β-cells in all forms of diabetes mellitus. The identification of small molecules capable of protecting cytokine-induced apoptosis could form the basis of useful therapeutic interventions. Here in, we present the discovery and synthesis of new benzimidazole derivatives, capable of rescuing pancreatic β-cells from cytokine-induced apoptosis. Three hydrazone derivatives of benzimidazole significantly increased the cellular ATP levels, reduced caspase-3 activity, reduced nitrite production and increased glucose-stimulated insulin secretion in the presence of proinflammatory cytokines. These findings suggest that these compounds may protect β-cells from the harmful effects of cytokines and may serve as candidates for therapeutic intervention for diabetes.
  19. Akhtar MN, Lam KW, Abas F, Maulidiani, Ahmad S, Shah SA, et al.
    Bioorg Med Chem Lett, 2011 Jul 1;21(13):4097-103.
    PMID: 21641207 DOI: 10.1016/j.bmcl.2011.04.065
    Bioassay-guided extraction of the stem bark of Knema laurina showed the acetylcholinesterase (AChE) inhibitory activity of DCM and hexane fractions. Further repeated column chromatography of hexane and DCM fractions resulted in the isolation and purification of five alkenyl phenol and salicylic acid derivatives. New compounds, (+)-2-hydroxy-6-(10'-hydroxypentadec-8'(E)-enyl)benzoic acid (1) and 3-pentadec-10'(Z)-enylphenol (2), along with known 3-heptadec-10'(Z)-enylphenol (3), 2-hydroxy-6-(pentadec-10'(Z)-enyl)benzoic acid (4), and 2-hydroxy-6-(10'(Z)-heptadecenyl)benzoic acid (5) were isolated from the stem bark of this plant. Compounds (1-5) were tested for their acetylcholinesterase inhibitory activity. The structures of these compounds were elucidated by the 1D and 2D NMR spectroscopy, mass spectrometry and chemical derivatizations. Compound 5 showed strong acetylcholinesterase inhibitory activity with IC(50) of 0.573 ± 0.0260 μM. Docking studies of compound 5 indicated that the phenolic compound with an elongated side chain could possibly penetrate deep into the active site of the enzyme and arrange itself through π-π interaction, H-bonding, and hydrophobic contacts with some critical residues along the complex geometry of the active gorge.
  20. Khan KM, Rahim F, Wadood A, Taha M, Khan M, Naureen S, et al.
    Bioorg Med Chem Lett, 2014 Apr 1;24(7):1825-9.
    PMID: 24602903 DOI: 10.1016/j.bmcl.2014.02.015
    Bisindole analogs 1-17 were synthesized and evaluated for their in vitro β-glucuronidase inhibitory potential. Out of seventeen compounds, the analog 1 (IC50=1.62±0.04 μM), 6 (IC50=1.86±0.05 μM), 10 (IC50=2.80±0.29 μM), 9 (IC50=3.10±0.28 μM), 14 (IC50=4.30±0.08 μM), 2 (IC50=18.40±0.09 μM), 19 (IC50=19.90±1.05 μM), 4 (IC50=20.90±0.62 μM), 7 (IC50=21.50±0.77 μM), and 3 (IC50=22.30±0.02 μM) showed superior β-glucuronidase inhibitory activity than the standard (d-saccharic acid 1,4-lactone, IC50=48.40±1.25 μM). In addition, molecular docking studies were performed to investigate the binding interactions of bisindole derivatives with the enzyme. This study has identified a new class of potent β-glucouronidase inhibitors.
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