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ABSTRACT: The bioactive compound 2-(4-methyl-2′-bip-henyl)-4-amino-1,2,4-triazole-3-thiol, F.W. 282.09 was synthesized, characterized
by spectroscopic techniques and confirmed by X-ray crystal structure analysis. The title compound crystallizes in monoclinic
class under the space group P21/c with cell parameters, a=11.273(3)Å, b=17.245(1)Å, c=7.413(1)Å, β=97.742(5)° and Z=4. The structure exhibits inter-molecular hydrogen bonding of the type N–H···S.
Structural Chemistry 04/2012; 17(1):91-95. · 1.85 Impact Factor
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ABSTRACT: The angiogenic process is controlled by variety of factors of which the vascular endothelial growth factor (VEGF) pathway plays a major role. A series of heparan sulfate mimetic small molecules targeting VEGF/VEGFR pathway has been synthesized. Among them, compound 8 (2-butyl-5-chloro-3-(4-nitro-benzyl)-3H-imidazole-4-carbaldehyde) was identified as a significant binding molecule for the heparin-binding domain of VEGF, determined by high-throughput-surface plasmon resonance assay. The data predicted strong binding of compound 8 with VEGF which may prevent the binding of VEGF to its receptor. We compared the structure of compound 8 with heparan sulfate (HS), which have in common the functional ionic groups such as sulfate, nitro and carbaldehyde that can be located in similar positions of the disaccharide structure of HS. Molecular docking studies predicted that compound 8 binds at the heparin binding domain of VEGF through strong hydrogen bonding with Lys-30 and Gln-20 amino acid residues, and consistent with the prediction, compound 8 inhibited binding of VEGF to immobilized heparin. In vitro studies showed that compound 8 inhibits the VEGF-induced proliferation migration and tube formation of mouse vascular endothelial cells, and finally the invasion of a murine osteosarcoma cell line (LM8G7) which secrets high levels of VEGF. In vivo, these effects produce significant decrease of tumor burden in an experimental model of liver metastasis. Collectively, these data indicate that compound 8 may prevent tumor growth through a direct effect on tumor cell proliferation and by inhibition of endothelial cell migration and angiogenesis mediated by VEGF. In conclusion, compound 8 may normalize the tumor vasculature and microenvironment in tumors probably by inhibiting the binding of VEGF to its receptor.
PLoS ONE 01/2012; 7(8):e39444. · 4.09 Impact Factor
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ABSTRACT: Levamisole, an imidazo(2,1-b)thiazole derivative, has been reported to be a potential antitumor agent. In the present study, we have investigated the mechanism of action of one of the recently identified analogues, 4a (2-benzyl-6-(4'-fluorophenyl)-5-thiocyanato-imidazo[2,1-b][1], [3], [4]thiadiazole).
ROS production and expression of various apoptotic proteins were measured following 4a treatment in leukemia cell lines. Tumor animal models were used to evaluate the effect of 4a in comparison with Levamisole on progression of breast adenocarcinoma and survival. Immunohistochemistry and western blotting studies were performed to understand the mechanism of 4a action both ex vivo and in vivo.
We have determined the IC(50) value of 4a in many leukemic and breast cancer cell lines and found CEM cells most sensitive (IC(50) 5 µM). Results showed that 4a treatment leads to the accumulation of ROS. Western blot analysis showed upregulation of pro-apoptotic proteins t-BID and BAX, upon treatment with 4a. Besides, dose-dependent activation of p53 along with FAS, FAS-L, and cleavage of CASPASE-8 suggest that it induces death receptor mediated apoptotic pathway in CEM cells. More importantly, we observed a reduction in tumor growth and significant increase in survival upon oral administration of 4a (20 mg/kg, six doses) in mice. In comparison, 4a was found to be more potent than its parental analogue Levamisole based on both ex vivo and in vivo studies. Further, immunohistochemistry and western blotting studies indicate that 4a treatment led to abrogation of tumor cell proliferation and activation of apoptosis by the extrinsic pathway even in animal models.
Thus, our results suggest that 4a could be used as a potent chemotherapeutic agent.
PLoS ONE 01/2012; 7(9):e43632. · 4.09 Impact Factor
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ABSTRACT: To explore the anticancer effect associated with the piperidine framework, several (substituted phenyl) {4-[3-(piperidin-4-yl)propyl]piperidin-1-yl} methanone derivatives 3(a-i) were synthesized. Variation in the functional group at N-terminal of the piperidine led to a set of compounds bearing amide moiety. Their chemical structures were confirmed by (1) H NMR, IR and mass spectra analysis. Among these, compounds 3a, 3d and 3e were endowed with antiproliferative activity. The most active compound among this series was 3a with nitro and fluoro substitution on the phenyl ring of aryl carboxamide moiety, which inhibited the growth of human leukemia cells (K562 and Reh) at low concentration. Comparison with other derivative (3h) results shown by LDH assay, cell cycle analysis and DNA fragmentation suggested that 3a is more potent to induce apoptosis.
Chemical Biology & Drug Design 07/2011; 78(4):622-30. · 2.28 Impact Factor
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ABSTRACT: In search of synthetic chemotherapeutic substances capable of inhibiting, retarding, or reversing the process of multistage carcinogenesis, we synthesised a series of novel 1-(4-methoxybenzyl)-3-cyclopropyl-1H-pyrazol-5-amine derivatives 9(a-h) by a nucleophilic substitution reaction and characterized by (1)H and (13)C nuclear magnetic resonance (NMR), liquid chromatography mass spectrometry (LC/MS), Fourier-transform infrared (FTIR), and elemental analysis. These novel compounds were evaluated for their efficacy in inhibiting VERO normal and MCF-7 breast cancer cells proliferation by trypan blue exclusion assay, MTT assay, [(3)H] thymidine incorporation assay and DNA fragmentation analysis. Among the series, some compounds exhibited interesting growth inhibitory effects against cell lines. From the Structure-Activity Relationship studies, it has been revealed that, both novel patented compounds and therapeutic protocols of N-terminal pyrazole ring structures play key role in the antiproliferative activity.
Recent patents on anti-cancer drug discovery. 01/2011; 6(2):186-95.
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ABSTRACT: A novel pyranoside mimetic compound, DMBO (2-(2,6-difluorophenyl)-5-(4-methoxyphenyl)-1-oxa-3-azaspiro[5.5]undecane), was designed and synthesized. The sugar mimicking behavior of DMBO was addressed by its ability to bind several growth factors/cytokines such as vascular endothelial growth factor (VEGF), heparin-binding epidermal growth factor-like growth factor (HB-EGF), and tumor necrosis factor (TNF)-α as demonstrated by the recently developed surface plasmon resonance assay. DMBO exhibited strong anti-proliferation activity in vitro against tumor cells including a highly metastatic murine osteosarcoma cell line LM8G7 that secretes VEGF as well as two human ovarian cell lines, OVSAHO and SKOV-3, which secrete TNF-α and HB-EGF respectively. Furthermore, DMBO inhibited the metastatic activity to the mouse liver of LM8G7 cells injected from a lateral tail vein, and affected the heparan-degrading activity of LM8G7 cells. Here, we report that DMBO acts as a human heparanase inhibitor in vitro possibly as a substrate mimetic. DMBO also inhibited the migration and invasion of LM8G7 cells and angiogenic events such as endothelial cell proliferation, migration and capillary tube-like formation in vitro. More prominently, the administration of DMBO with heparin resulted in synergistic anti-tumor effects in mouse modelofosteosarcoma. These preclinical data shows the potential anti-cancer effects of DMBO.
Cancer letters 11/2010; 297(2):231-43. · 4.86 Impact Factor
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ABSTRACT: The present work deals with the anticancer effect of benzimidazole derivatives associated with the pyridine framework. By varying the functional group at N-terminal of the benzimidazole by different L-amino acids, several 2-(4-(2,2,2-trifluoroethoxy)-3-methylpyridin-2-ylthio)-1Hbenzo[d]imidazole derivatives 9(a-j) were synthesized. Their chemical structures were confirmed by (1)H NMR, IR and mass spectroscopic techniques. The synthesized compounds were examined for their antiproliferative effects against human leukemia cell lines, K562 and CEM. The preliminary results showed most of the derivatives had moderate antitumor activity. Compound 9j containing cysteine residue exhibited good inhibition compared to other amino acid resides. In addition DNA fragmentation results suggest that 9j is more cytotoxic and able to induce apoptosis.
Archives of Pharmacal Research 10/2009; 32(10):1335-43. · 1.59 Impact Factor
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ABSTRACT: We report here the synthesis and preliminary evaluation of novel 1-(4-methoxyphenethyl)-1H-benzimidazole-5-carboxylic acid derivatives 6(a-k) and their precursors 5(a-k) as potential chemotherapeutic agents. In each case, the structures of the compounds were determined by FTIR, (1)H NMR and mass spectroscopy. Among the synthesized molecules, methyl 1-(4-methoxyphenethyl)-2-(4-fluoro-3-nitrophenyl)-1H-benzimidazole-5-carboxylate (5a) induced maximum cell death in leukemic cells with an IC(50) value of 3 microM. Using FACS analysis we show that the compound 5a induces S/G2 cell cycle arrest, which was further supported by the observed down regulation of CDK2, Cyclin B1 and PCNA. The observed downregulation of proapoptotic proteins, upregulation of antiapoptotic proteins, cleavage of PARP and elevated levels of DNA strand breaks indicated the activation of apoptosis by 5a. These results suggest that 5a could be a potent anti-leukemic agent.
Bioorganic & medicinal chemistry letters 09/2009; 19(16):4594-600. · 2.65 Impact Factor
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ABSTRACT: Earlier we have reported the effect of arecoline thiazolidinone and morpholino arecoline analogues as muscarinic receptor 1 agonist in Alzheimer's dementia models. To elucidate further our SAR study on the chemistry and muscarinic receptor binding efficacy, a series of novel N-alkyl/aryl substituted thiazolidinone arecoline analogues 6(a-m) were designed and synthesized from 3-pyridine carboxaldehyde by reacting with different amines in the presence of gamma-ferrite as catalyst and subjected to in vitro muscarinic receptor binding studies using male Wistar rat brain membrane homogenate and extended to in vivo pharmacological evaluation of memory and learning in male Wistar rats. Derivative 6j having diphenylamine moiety attached to nitrogen of thiazolidinone showed significant affinity for the M1 receptor binding.
European journal of medicinal chemistry 09/2009; 44(12):4848-54. · 3.27 Impact Factor
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ABSTRACT: In the scope of the research program aiming to perform the synthesis and pharmacological evaluation of novel possible anti-inflammatory compounds, in this manuscript, we report the synthesis of novel carboxamide 9a-d and thioamide 10a-d derivatives from the benzophenone and piperidine nucleus. Variation in the functional group at the N-terminal of piperidine led to two sets of compounds, bearing the carboxamide and thioamide, respectively. The characterization of this new class of compounds was performed with (1)H-NMR, LC-MS, IR, and elemental analysis. The newly synthesized compounds were screened for their anti-inflammatory activity by carrageenan-induced foot pad oedema assay and were compared with a standard drug. All the compounds exhibited anti-inflammatory activity at the dose of 30 mg/kg p.o. with varying degree from 52 to 67% inhibition of oedema. The compounds 9d and 10d with dichloro and fluoro substitution showed more potent activity at 30 mg/kg p.o. than the standard drug.
Archiv der Pharmazie 07/2009; 342(8):476-83. · 1.71 Impact Factor
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ABSTRACT: A series of new azaspiro bicyclic hydantoin derivatives has been designed and synthesized. Initially, the anti-proliferative effect of the hydantoin derivatives was evaluated against human ovarian cancer cells (SKOV-3 and OVSAHO) and murine osteosarcoma cells (LM8 and LM8G7). Among the tested compounds, 8-(3-fluorobenzyl)-1'-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4'-imidazolidine]-2',5'-dione (7h) and 8-(3,4-difluorobenzyl)-1'-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4'-imidazolidine]-2',5'-dione (7i) showed a significant anti-proliferative activity against the OVSAHO and LM8G7 cells. The real-time monitoring of the effect of the compounds 7h and 7i against the proliferation of LM8G7 was revealed that resulting IC(50) values were 102microM and 13microM, respectively. We reasoned that the presence of fluorine atom at the 3rd position of the phenyl ring of the hydantoin side chain may determine the potency of the molecule. Furthermore, the compound 7i inhibited the tube formation of the mouse endothelial cells. Finally, the treatment of the compound 7i against the proliferation of LM8G7 cells demonstrated the down regulation of the secretion of VEGF, indicate the potential angioinhibitory effects. In conclusion, our findings demonstrate the suppression of the secretion of VEGF by LM8G7 cells by the compound 7i might contribute at least in part to the antitumor action.
Bioorganic & medicinal chemistry 07/2009; 17(14):4928-34. · 2.82 Impact Factor
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ABSTRACT: In the scope of the research program aiming to perform the synthesis and pharmacological evaluation of novel possible anti-inflammatory compounds, in this manuscript, we report the synthesis of novel carboxamide 9a-d and thioamide 10a-d derivatives from the benzophenone and piperidine nucleus. Variation in the functional group at the N-terminal of piperidine led to two sets of compounds, bearing the carboxamide and thioamide, respectively. The characterization of this new class of compounds was performed with 1H-NMR, LC-MS, IR, and elemental analysis. The newly synthesized compounds were screened for their anti-inflammatory activity by carrageenan-induced foot pad oedema assay and were compared with a standard drug. All the compounds exhibited anti-inflammatory activity at the dose of 30 mg/kg p.o. with varying degree from 52 to 67% inhibition of oedema. The compounds 9d and 10d with dichloro and fluoro substitution showed more potent activity at 30 mg/kg p.o. than the standard drug.
Archiv der Pharmazie 06/2009; 342(8):476 - 483. · 1.71 Impact Factor
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ABSTRACT: Hypocholinergic function associated with Alzheimer's disease (AD) is well-accepted hypothesis, in this regard, many research attempts have been made to elevate the reduced cholinergic neurotransmission, among them two main treatment strategies were widely explored, namely stimulation of muscarinic receptor 1 and/or reversible inhibition of acetylcholinesterase (AChE) enzyme. In an attempt to improve the efficacy and to minimize general side effects of these AChE inhibitors, many lead molecules are developed in research; one among them is piperidine derivative. Donazepil is a widely prescribed AChE inhibitor which displays a piperidine ring in its structure. In the present study, we have docked cis-2,6-dimethyl piperidine sulfonamides (3a-i) on AChE enzyme and synthesized by nucleophilic substitution reaction between cis-2,6-dimethyl piperidine and alkyl/aryl sulfonyl chlorides in the presence of triethylamine. These piperidine sulfonamides were subjected to in vitro AChE enzyme inhibition studies and in vivo antiamnesic study to reverse scopolamine induced memory loss in rats. Two derivatives (3a and f) in this class of piperidines (3a-i) showed considerable inhibition against different sources of AChE in vitro and reduced average number of mistakes done by wistar rats as compared to scopolamine treated group in vivo (rodent memory evaluation).
European journal of medicinal chemistry 06/2009; 44(10):4057-62. · 3.27 Impact Factor
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ABSTRACT: Hydantoin derivatives possess a variety of biochemical and pharmacological properties and consequently are used to treat many human diseases. However, there are only few studies focusing on their potential as cancer therapeutic agents. In the present study, we have examined anticancer properties of two novel spirohydantoin compounds, 8-(3,4-difluorobenzyl)-1'-(pent-4-enyl)-8-azaspiro[bicyclo[3.2.1] octane-3,4'-imidazolidine]-2',5'-dione (DFH) and 8-(3,4-dichlorobenzyl)-1'-(pent-4-enyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4'-imidazolidine]-2',5'-dione (DCH). Both the compounds exhibited dose- and time-dependent cytotoxic effect on human leukemic cell lines, K562, Reh, CEM and 8E5. Incorporation of tritiated thymidine ([(3)H] thymidine) in conjunction with cell cycle analysis suggested that DFH and DCH inhibited the growth of leukemic cells. Downregulation of PCNA and p-histone H3 further confirm that the growth inhibition could be at the level of DNA replication. Flow cytometric analysis indicated the accumulation of cells at subG1 phase suggesting induction of apoptosis, which was further confirmed and quantified both by fluorescence-activated cell sorting (FACS) and confocal microscopy following annexin V-FITC/propidium iodide (PI) staining. Mechanistically, our data support the induction of apoptosis by activation of the mitochondrial pathway. Results supporting such a model include, elevated levels of p53, and BAD, decreased level of BCL2, activation and cleavage of caspase 9, activation of procaspase 3, poly (ADP-ribosyl) polymerase (PARP) cleavage, downregulation of Ku70, Ku80 and DNA fragmentation. Based on these results we discuss the mechanism of apoptosis induced by DFH and its implications in leukemia therapy.
Biochemical pharmacology 11/2008; 77(3):348-63. · 4.25 Impact Factor
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ABSTRACT: The discovery of cholinergic deficit in Alzheimer's disease (AD) patient's brain has triggered research efforts, using cholinomimetic approaches for their efficacy in AD therapy. Various therapies may be of potential clinical use in AD. Among these are cholinergic agents, which include muscarinic agonists, acetylcholinesterase inhibitors, and acetylcholine releasing agents. One of the muscarinic agonists tested in AD is arecoline and its bioisosters, which are widely explored as muscarinic receptor 1 agonist (M1 receptor agonist) in AD research. In this regard, five-membered heterocyclic ring system attached arecoline basic nucleus (N-methyl tetrahydropyridines) at third position has been extensively researched on. The present research involved synthesis of arecoline thiazolidinones 5(a-j) by using dipolar addition of 3-aminopyridine and alkyl/aryl carboxaldehydes in presence of gamma ferrite as catalyst. The resulting products were methylated and reduced to get desired products. Subsequently the synthesized arecoline thiazolidinones were subjected to in vitro muscarinic receptor binding studies using male Wistar rat brain (cerebral cortex) membrane homogenate and extended this in vitro study to in vivo pharmacological evaluation of memory and learning in male Wistar rats. Four derivatives (5a-5c and 5e) showed considerable M1 receptor binding affinity (in vitro) and elicited beneficial effects in vivo memory and learning models (Rodent memory evaluation, plus and Y maze studies).
Neurochemistry International 03/2008; 52(3):376-83. · 2.86 Impact Factor
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ABSTRACT: In this study we report that, imidazole derivatives can induce apoptosis in Ehrlich ascites tumor (EAT) cells, which is clearly evident from annexin-V staining, flow cytometric analysis of cell cycle phase distribution and DNA fragmentation. Delineating further into molecular mechanisms leading to apoptosis of EAT cells, we observed that imidazole derivatives induce tumor cell death by the up-regulation of proto-oncoprotein Bax, release of cytochrome c from the mitochondria which activates caspase-3 and activated caspase-3 activates CAD (Caspase Activated DNase) causes DNA fragmentation. The status of Bcl-2 remains unaltered in EAT cells, and the under expression of Bcl-2 and up-regulation of Bax resulted in the increase of Bax: Bcl-2 ratio suggesting that Bcl-2 family involved in the control of apoptosis. These results suggest a further possible clinical application of imidazole derivatives as pro-apoptotic agent in association with conventional chemotherapeutic agents.
Investigational New Drugs 09/2007; 25(4):343-50. · 3.36 Impact Factor
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ABSTRACT: A new series of N-substituted 2-butyl-5-chloro-3H-imidazole-4-carbaldehyde derivatives were synthesized by using the different bioactive heteroaralkyl halides with 2-butyl-4-chloro-1H-imidazole-5-carbaldehyde in presence of powdered potassium carbonate in DMF medium. These compounds were screened for their antitumor activity. Our results show that treatment of imidazole derivatives inhibit proliferation EAT cells, decreases the ascites volume and increases the survivability of the animals in vivo. These compounds also inhibited the cellular proliferation of HUVEC cells in vitro by MTT assay. Further, these compounds could induce apoptosis, which is evident by the nuclear condensation of imidazole derivatives treated EAT cells in vivo by the cytological analysis. We have identified that pyrrolidine substituted imidazole derivative as potent anti-tumor compound. These inhibitors could represent as promising candidates for anticancer therapies, where the formation of peritoneal malignant ascites is a major cause of morbidity and mortality.
Medicinal Chemistry 06/2007; 3(3):269-76. · 1.50 Impact Factor
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Analytical Sciences X-ray Structure Analysis Online 01/2007; 23:X181-X182.
