ORCID Profile
0000-0001-6241-7547
Current Organisations
University of Agriculture Faisalabad
,
Universiti Sains Malaysia
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Publisher: Informa UK Limited
Date: 02-09-2013
Publisher: International Union of Crystallography (IUCr)
Date: 24-02-2012
Publisher: International Union of Crystallography (IUCr)
Date: 05-05-2012
DOI: 10.1107/S1600536812019344
Abstract: In the title compound, C 26 H 28 N 4 2+ ·2PF 6 − , the complete cation is generated by a crystallographic twofold axis. The benzimidazole ring is almost planar (r.m.s. deviation = 0.0207 Å) and makes dihedral angles of 50.12 (2)° with its symmetry-related component and 65.81 (2)° with the central benzene ring. In the crystal, molecules are linked into a three-dimensional network by C—H...F interactions. A π–π interaction with a centroid–centroid distance of 3.530 (1) Å is observed. Four F atoms of the hexafluorophosphate anion are disordered over two sets of sites in a 0.889 (6):0.111 (6) ratio.
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.EJMECH.2014.11.005
Abstract: A series of benzimidazole-based N-heterocyclic carbene (NHC) proligands {1-benzyl-3-(2-methylbenzyl)-benzimidazolium bromide/hexafluorophosphate (1/4), 1,3-bis(2-methylbenzyl)-benzimidazolium bromide/hexafluorophosphate (2/5) and 1,3-bis(3-(2-methylbenzyl)-benzimidazolium-1-ylmethylbenzene dibromide/dihexafluorophosphate (3/6)} has been synthesized by the successive N-alkylation method. Ag complexes {1-benzyl-3-(2-methylbenzyl)-benzimidazol-2-ylidenesilver(I) hexafluorophosphate (7), 1,3-bis(2-methylbenzyl)-benzimidazol-2-ylidenesilver(I) hexafluorophosphate (8) and 1,3-bis(3-(2-methylbenzyl)-benzimidazol-2-ylidene)-1-ylmethylbenzene disilver(I) dihexafluorophosphate (9)} of NHC ligands have been synthesized by the treatment of benzimidazolium salts with Ag2O at mild reaction conditions. Both, NHC proligands and Ag-NHC complexes have been characterized by (1)H and (13)C{(1)H} NMR and FTIR spectroscopy and elemental analysis technique. Additionally, the structure of the NHC proligand 5 and the mononuclear Ag complexes 7 and 8 has been elucidated by the single crystal X-ray diffraction analysis. Both the complexes exhibit the same general structural motif with linear coordination geometry around the Ag centre having two NHC ligands. Preliminary in vitro antibacterial potentials of reported compounds against a Gram negative (Escherichia coli) and a Gram positive (Bacillus subtilis) bacteria evidenced the higher activity of mononuclear silver(I) complexes. The anticancer studies against the human derived colorectal cancer (HCT 116) and colorectal adenocarcinoma (HT29) cell lines using the MTT assay method, revealed the higher activity of Ag-NHC complexes. The benzimidazolium salts 4-6 and Ag-NHC complexes 7-9 displayed the following IC50 values against the HCT 116 and HT29 cell lines, respectively, 31.8 ± 1.9, 15.2 ± 1.5, 4.8 ± 0.6, 10.5 ± 1.0, 18.7 ± 1.6, 1.20 ± 0.3 and 245.0 ± 4.6, 8.7 ± 0.8, 146.1 ± 3.1, 7.6 ± 0.7, 5.5 ± 0.8, 103.0 ± 2.3 μM.
Publisher: Springer Science and Business Media LLC
Date: 18-01-2013
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 02-2013
Publisher: MDPI AG
Date: 26-06-2015
Publisher: International Union of Crystallography (IUCr)
Date: 05-02-2011
Publisher: Elsevier BV
Date: 02-2015
Publisher: Springer Science and Business Media LLC
Date: 07-02-2013
Abstract: Since the first successful synthesis of Ag(I)-N-heterocyclic carbene complex in 1993, this class of compounds has been extensively used for transmetallation reactions where the direct synthesis using other metal ions was either difficult or impossible. Initially, silver(I)-NHC complexes were tested for their catalytic potential but could not get fame because of lower potential compare to other competent compounds in this field however, these compounds proved to have vital antimicrobial activities. These encouraging biomedical applications further convinced researchers to test these compounds against cancer. The current work has been carried out with this aim. N - i propylbenzimidazole was synthesized by reaction of benzimidazole with i propyl bromide. The subsequent treatment of the resulting N -alkylbenzimidazole with ortho / meta / para -(bromomethylene) benzene afforded corresponding bis -benzimidazolium bromides ( 5 - 7 ). The counter anion (Br-) of each salt was replaced by hexaflourophosphate (PF 6 - ) for the ease of handling and further purification ( 8 - 10 ). Each salt (Ligand), in halide form, was further allowed to react with Ag 2 O with stirring at room temperature for a period of two days to synthesize dinuclear Ag(I)-NHC complexes ( 11 - 13 ). All synthesized compounds were characterized by spectroscopic techniques and microanalysis. Molecular structures of compounds 5 , 9 & 10 were established through single crystal x-ray diffraction technique. All the compounds were assessed for their anti-proliferation test on human colorectal cancer cell line (HCT 116). Results showed that the ligands ( 5-10 ) showed mild to negligible cytotoxicity on HCT 116 cells whereas respective silver complexes ( 11-13 ) exhibited dose dependent cytotoxicity towards the colon cancer cells with IC 50 ranges between 9.7 to 44.5 μM. Interestingly, the complex 13 having para -xylyl spacer was found the most active (IC 50 9.7 μM) that verifies our previously reported results. All the bis-benzimidazolium salts ( 8-10 ) were found inactive whereas after bonding with silver cations, the Ag(I)-NHC complexes ( 11-13 ) showed a dose dependent cytotoxic activity. This proved that silver practice an important role in death of cancer cells. Also, the N -alkyl/aryl substitutions and ortho/metal ara xylyl units regulate the cytotoxicity.
Publisher: International Union of Crystallography (IUCr)
Date: 03-03-2012
DOI: 10.1107/S1600536812008331
Abstract: In the title hydrated molecular salt, C 38 H 52 N 4 2+ ·2Br − ·H 2 O, the central benzene ring of the dication makes dihedral angles of 89.47 (13) and 72.69 (12)° with the pendant benzimidazol-3-ium rings. The conformations of the octyl side chains are completely different. In the crystal, the components are linked by O—H...Br, C—H...Br and C—H...O hydrogen bonds into a two-dimensional network lying parallel to the ac plane. Aromatic π–π stacking interactions are also observed [shortest centroid-to-centroid separation = 3.5047 (16) Å].
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.EJPS.2016.08.032
Abstract: Glioblastoma multiforme is a highly malignant, heterogenic, and drug resistant tumor. The blood-brain barrier (BBB), systemic cytotoxicity, and limited specificity are the main obstacles in designing brain tumor drugs. In this study a computational approach was used to design brain tumor drugs that could downregulate VEGF and IL17A in glioblastoma multiforme type four. Computational screening tools were used to evaluate potential candidates for antiangiogenic activity, target binding, BBB permeability, and ADME physicochemical properties. Additionally, in vitro cytotoxicity, migration, invasion, tube formation, apoptosis, ROS and ELISA assays were conducted for molecule 6 that was deemed most likely to succeed. The efflux ratio of membrane permeability and calculated docking scores of permeability to glycoproteins (P-gps) were used to determine the BBB permeability of the molecules. The results showed BBB permeation for molecule 6, with the predicted efficiency of 0.55kcal/mol and binding affinity of -37kj/mol corresponding to an experimental efflux ratio of 0.625 and predicted -15kj/mol of binding affinity for P-gps. Molecule 6 significantly affected the angiogenesis pathways by 2-fold downregulation of IL17A and VEGF through inactivation of active sites of HSP90 (predicted binding: -37kj/mol, predicted efficiency: 0.55kcal/mol) and p23 (predicted binding: 12kj/mol, predicted efficiency: 0.17kcal/mol) chaperon proteins. Additionally, molecule 6 activated the 17.38% relative fold of ROS level at 18.3μg/mL and upregulated the caspase which lead the potential synergistic apoptosis through the antiangiogenic activity of molecule 6 and thereby the highly efficacious anticancer upshot. The results indicate that the binding of the molecules to the therapeutic target is not essential to produce a lethal effect on cancer cells of the brain and that antiangiogenic efficiency is much more important.
Publisher: Informa UK Limited
Date: 02-02-2015
Publisher: Oxford University Press (OUP)
Date: 14-07-2014
DOI: 10.1111/JPHP.12272
Abstract: Recently, we have isolated koetjapic acid (KA) from Sandoricum koetjape and identified its selective anticancer potentiality against colorectal carcinoma. KA is quite likely to be useful as a systemic anticancer agent against colorectal malignancy. However, with extremely low solubility, KA has to be converted into a biocompatible solubilized form without compromising the bioefficacy. Objective of this study is to enhance solubility of KA and to evaluate anticancer efficacy of potassium koetjapate in human colorectal cancer cells. (2-Hydroxypropyl)-β-cyclodextrin inclusion complex and solid dispersions (carboxymethyl cellulose, polyvinylpyrrolidone and sodium lauryl sulphate) of KA were prepared. In addition, a salt of KA, potassium koetjapate was synthesized. Potassium koetjapate demonstrated higher solubility than the other tested formulations with enhanced cytotoxicity against HCT 116 cells. The enhanced efficacy of potassium koetjapate is attributed to apoptotic induction of nuclear condensation and disruption of mitochondrial membrane potential in the cells. Interestingly, potassium koetjapate was found to be safe in rats after oral administration (LD50 & 2000 mg/kg). The salt formulation of KA appears to modulate the capability of the parent compound by enhancing its solubility and improves its bioefficacy against colon cancer cells, suggesting attractive roles for its applications in medicine.
Publisher: Hindawi Limited
Date: 2013
DOI: 10.1155/2013/804683
Abstract: This paper describes synthesis, characterization (NMR, FT-IR, microanalysis, and X-ray crystallography), in vitro anticancer activity of ortho / para -xylyl linked bis-imidazolium salts ( 4 - 5 ) and respective dinuclear Ag(I) N -heterocyclic carbene (NHC) complexes ( 6 - 7 ). All the compounds were tested for their cytotoxicity against human colorectal cancer (HCT 116) and breast cancer (MCF-7) cell lines. According to cell viability measurements using MTT assay, all the complexes ( 6 - 7 ) showed a dose-dependent cytotoxic activity against both the cell lines, whereas respective salts ( 4 - 5 ) proved to be inactive. The complexes ( 6 - 7 ) demonstrated significant activity with IC 50 values range 5.6–20.3 μ M for HCT 116 and 1.12–6.38 μ M for MCF-7. 5-Fluorouracil was used as standard drug (IC 50 = 5.9 μ M) for HCT 116, whereas tamoxifen was used as standard drug for MCF-7 (IC 50 = 14 μ M) cell line.
Publisher: Informa UK Limited
Date: 14-01-2015
Publisher: Elsevier BV
Date: 2016
Publisher: Informa UK Limited
Date: 13-06-2016
Publisher: Springer Science and Business Media LLC
Date: 31-01-2020
DOI: 10.1007/S12010-019-03186-9
Abstract: Synthesis and anticancer studies of three symmetrically and non-symmetrically substituted silver(I)-N-Heterocyclic carbene complexes of type [(NHC)
Publisher: Elsevier BV
Date: 12-2017
Publisher: Springer Science and Business Media LLC
Date: 09-10-2012
Publisher: Springer Science and Business Media LLC
Date: 17-10-2013
Publisher: Springer Science and Business Media LLC
Date: 22-01-2013
Publisher: Bentham Science Publishers Ltd.
Date: 30-06-2015
DOI: 10.2174/1573406411666150101153115
Abstract: Azolium (imidazolium and benzimidazolium) salts are known as stable precursors for the synthesis of Metal-N-Heterocyclic Carbene (M-NHC) complexes. Recently, some reports have been compiled indicating that benzimidazolium salts have anticarcinogenic properties. The current research is the further investigation of this phenomenon. Three ortho-xylene linked bis-benzimidazolium salts (1-3) with octyl, nonyl and decyl terminal chain lengths have been synthesized. Each of the compounds was characterized using FT-IR and NMR spectroscopic techniques. The molecular geometries of two of the salts (1-2) have been established using X-ray crystallographic technique. The compounds were tested for their cytotoxic properties against three cancerous cell lines namely, human colon cancer (HCT 116), human colorectal adenocarcinoma (HT- 29) and human breast adenocarcinoma (MCF-7). Mouse embryonic fibroblast (3T3-L1) was used as the model cell line of normal cells. The compounds showed selective anti-proliferative activities against the colorectal carcinoma cells. For HCT 116 and HT-29 cells, the IC50 values ranged 0.9-2.6 µM and 4.0-10.0 µM, respectively. The salts 1 and 3 displayed moderate cytotoxicity against the breast cancer (MCF-7) cells with IC50 58.2 and 13.3 µM, respectively. However, the salt 2 produced strong cytotoxicity against MCF-7 cells with IC50 4.4 µM. Interestingly, the compounds demonstrated poor cytotoxic effects towards the normal cells (3T3-L1) as the IC50 was found to be as high as 48.0 µM. Salts 2 and 3 demonstrated more pronounced anti-proliferative effect than the standard drugs used (5-Flourouracil and Tamoxifen).
Publisher: Informa UK Limited
Date: 22-09-2016
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.MVR.2016.04.009
Abstract: We recently reported the antineovascularization effect of scopoletin on rat aorta and identified its potential anti-angiogenic activity. Scopoletin could be useful as a systemic chemotherapeutic agent against angiogenesis-dependent malignancies if its antitumorigenic activity is investigated and scientifically proven using a suitable human tumor xenograft model. In the present study, bioassay-guided (anti-angiogenesis) phytochemical investigation was conducted on Nicotiana glauca extract which led to the isolation of scopoletin. Further, anti-angiogenic activity of scopoletin was characterized using ex vivo, in vivo and in silico angiogenesis models. Finally, the antitumorigenic efficacy of scopoletin was studied in human colorectal tumor xenograft model using athymic nude mice. For the first time, an in vivo anticancer activity of scopoletin was reported and characterized using xenograft models. Scopoletin caused significant suppression of sprouting of microvessels in rat aortic explants with IC50 (median inhibitory concentration) 0.06μM. Scopoletin (100 and 200mg/kg) strongly inhibited (59.72 and 89.4%, respectively) vascularization in matrigel plugs implanted in nude mice. In the tumor xenograft model, scopoletin showed remarkable inhibition on tumor growth (34.2 and 94.7% at 100 and 200mg/kg, respectively). Tumor histology revealed drastic reduction of the extent of vascularization. Further, immunostaining of CD31 and NG2 receptors in the histological sections confirmed the antivascular effect of scopoletin in tumor vasculature. In computer modeling, scopoletin showed strong ligand affinity and binding energies toward the following angiogenic factors: protein kinase (ERK1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2). These results suggest that the antitumor activity of scopoletin may be due to its strong anti-angiogenic effect, which may be mediated by its effective inhibition of ERK1, VEGF-A, and FGF-2.
Publisher: International Union of Crystallography (IUCr)
Date: 25-06-2011
Publisher: Springer Science and Business Media LLC
Date: 18-07-2012
Publisher: International Union of Crystallography (IUCr)
Date: 04-02-2012
Publisher: Wiley
Date: 27-03-2013
DOI: 10.1002/AOC.2953
Publisher: Public Library of Science (PLoS)
Date: 07-03-2014
Publisher: Elsevier BV
Date: 03-2018
Publisher: Informa UK Limited
Date: 2013
Publisher: International Union of Crystallography (IUCr)
Date: 11-12-2010
Publisher: Elsevier BV
Date: 05-2015
DOI: 10.1016/J.JINORGBIO.2015.02.001
Abstract: Chronic inflammation intensifies the risk for malignant neoplasm, indicating that curbing inflammation could be a valid strategy to prevent or cure cancer. Cancer and inflammation are inter-related diseases and many anti-inflammatory agents are also used in chemotherapy. Earlier, we have reported a series of novel ligands and respective binuclear Ag(I)-NHC complexes (NHC=N-heterocyclic carbene) with potential anticancer activity. In the present study, a newly synthesized salt (II) and respective Ag(I)-NHC complex (III) of comparable molecular framework were prepared for a further detailed study. Preliminarily, II and III were screened against HCT-116 and PC-3 cells, wherein III showed better results than II. Both the compounds showed negligible toxicity against normal CCD-18Co cells. In FAM-FLICA caspase assay, III remarkably induced caspase-3/7 in HCT-116 cells most probably by tumor necrosis factor-alpha (TNF-α) independent intrinsic pathway and significantly inhibited in vitro synthesis of cytokines, interleukin-1 (IL-1) and TNF-α in human macrophages (U937 cells). In a cell-free system, both the compounds inhibited cyclooxygenase (COX) activities, with III being more selective towards COX-2. The results revealed that III has strong antiproliferative property selectively against colorectal tumor cells which could be attributed to its pro-apoptotic and anti-inflammatory abilities.
Publisher: Springer Science and Business Media LLC
Date: 10-07-2015
Publisher: International Union of Crystallography (IUCr)
Date: 21-01-2012
No related grants have been discovered for Muhammad Adnan Iqbal.