Faculty Publications
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Publications by NITK Faculty
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Item Synthesis, characterization and in vitro cytotoxic properties of some new Schiff and Mannich bases in Hep G2 cells(Birkhauser Boston, 2011) Dhanya, D.; Isloor, A.M.; Shetty, P.; Chandrakantha, B.; Satyamoorthy, K.A series of 5-substituted-4-amino-3-mercapto- 1,2,4-triazoles were synthesized and were treated with various 3-substituted pyrazole aldehydes to obtain a series of new Schiff bases (3a-l). Few of the selected Schiff bases were converted into Mannich bases by reaction with diphenylamine/morpholine in presence of formaldehyde in ethanol media (4a-e, 5a-e). These newly synthesized compounds were characterized by elemental analysis, IR, NMR and mass spectrometry studies. A comparative study on the cytotoxic activities of few selected Schiff and Mannich bases was done in HepG2 cells using MTT assay. Few of the screened Schiff bases, 3a, 3d, 3e, 3g and 3h showed dose dependent cytotoxic activity, 3a being the most potent with an IC50 value of 0.018 g/l comparable to the standard drug doxorubicin. Among the Mannich bases, 5b was the most active with an IC50 value of 0.034 g/l. The Schiff bases were found to be more active, when compared to Mannich bases derived from them. The morpholine derived Mannich bases were more potent than those obtained from diphenyl amine. © Springer Science+Business Media, LLC 2010.Item Synthesis, characterization and antimicrobial studies of some new pyrazole incorporated imidazole derivatives(2011) Vijesh, A.M.; Isloor, A.M.; Telkar, S.; Peethambar, S.K.; Rai, S.; Isloor, N.In the present study two series of novel imidazole derivatives containing substituted pyrazole moiety (3a-d and 5a-j) were synthesized. The first series were synthesized by the reaction of 3-aryl-1H-pyrazole-4-carbaldehyde thiosemicarbazones (2a-d) with DMAD and the second series by the reaction of 3-aryl-1H-pyrazole-4-carbaldehydes (1a-e) with 1,2-diketones (4a,b) in the presence of ammonium acetate. Structures of newly synthesized compounds were characterized by spectral studies. New compounds were screened for antifungal and antibacterial activities. Among the synthesized compounds, compound 3c was found to be potent antimicrobial agent. The acute oral toxicity study for the compound 3c was carried out and the experimental studies revealed that compound 3c is safe up to 3000 mg/kg and no death of animals were recorded. © 2011 Elsevier Masson SAS. All rights reserved.Item A novel series of homoallylic amines as potential antimicrobials(2012) Rai, U.S.; Isloor, A.M.; Shetty, P.; Isloor, N.; Padaki, M.; Fun, H.-K.An efficient catalytic three-component reaction of aldehydes, amines, and allyltributylstannate has been successfully developed to produce homoallylic amines at 25°C, in excellent yields, in the presence of 1 mol% of trifluoroacetic acid an inexpensive and environmentally friendly catalyst. Newly synthesized compounds were confirmed by spectral studies. Compound 3o was characterized by single crystal X-ray analysis. All the compounds were also screened for their antimicrobial activity. Halogen-substituted compounds namely 3d, 3g, 3n, and 3o have showed excellent antibacterial activity. © Springer Science+Business Media, LLC 2011.Item Synthesis and anti-inflammatory evaluation of some new 3,6-disubstituted-1, 2,4-triazolo-[3,4-b]-1,3,4-thiadiazoles bearing pyrazole moiety(2012) Malladi, S.; Isloor, A.M.; Shetty, P.; Fun, H.-K.; Telkar, S.; Mahmood, R.; Isloor, N.In the present study, a new series of 3,6-disubstituted- 1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazoles (4aj) have been synthesized by condensing 3-substituted-4-amino-5- mercapto-1,2,4-triazoles (1a-b) with various 3-substitutedpyrazole- 4-carboxylic acids (3a-e) in the presence ofPOCl3. The structures of newly synthesized compounds were characterized by elemental analysis, IR, 1H NMR, 13CNMR, and mass spectroscopic studies. Structure of the compound 4b was also confirmed by recording the single crystal X-ray structure. All the synthesized compounds were screened for their anti-inflammatory activities by carrageenan induced paw edema method. Anti-inflammatory screening indicated that, compounds 4d, 4e, and 4h were found to be biologically active whereas remaining compounds showed poor antiinflammatory activity. Also molecular docking studies were also performed for compounds which showed good antiinflammatory activity. © Springer Science+Business Media, LLC 2011.Item T3P mediated synthesis of some new quinoline substituted pyrazole derivatives and its antibacterial studies(2012) Chandrakantha, B.; Isloor, A.M.; Peethambar, S.K.; Shetty, P.A series of new N-(substituted)-5-phenyl-1-(quinolin-2-yl)-1H-pyrazole-4-carboxamide derivatives (5a-h) have been synthesized by condensing ethyl-3-(dimethylamino)-2-[(phenyl)carbonyl]prop-2-enoate 2 with quinoline-2-yl-hydrazine. Compound 3 is hydrolyzed into 4 which is upon further coupled with different aromatic/aliphatic amines using 50% prpopyl phosphonic anhydride (T3P) in ethyl acetate as coupling reagent to afford different quinoline substituted pyrazole carboxamide derivatives. All the newly synthesized compounds were screened for their invitro antibacterial studies against Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa. The results revealed that compounds 5d, 5f, and 5h showed good antibacterial activity towards all bacterial strains. These newly synthesized compounds were characterized by NMR, mass spectral, IR spectral study and also by C, H, N analyses.Item Design and regioselective synthesis of trifluoromethylquinolone derivatives as potent antimicrobial agents(Elsevier Masson SAS infos@masson.fr 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2013) Garudachari, B.; Isloor, A.M.; Satyanarayana, M.N.; Fun, H.-K.; Pavithra, N.; Kulal, A.Three series of new trifluoromethyl substituted quinolone derivatives were synthesized (4a-f, 6a-f and 8a-f) from corresponding substituted anilines by multi-step reactions. The regioselective alkylation with different alkyl halides were carried out by approaching two different routes to get the final products in good yield. Newly synthesized compounds were characterized by spectral study and also by C, H, N analyses. Three dimensional structure of 2b and 4b were also confirmed by single crystal X-ray studies. The final compounds (4a-f, 6a-f and 8a-f) were screened for their in-vitro antibacterial and antifungal activity by well plate method (zone of inhibition). The results revealed that, compounds 4a, 6b, 6c and 8e showed significant antibacterial activity as compared to the standard drug Ciprofloxacin. The compound 8a was found to be a potent antifungal agent. © 2013 Elsevier Masson SAS. All rights reserved.Item Synthesis of new 3-aryl-4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-1-phenyl-1H- pyrazole derivatives as potential antimicrobial agents(2013) Malladi, S.; Isloor, A.M.; Peethambar, S.K.; Fun, H.-K.New (E)-1-aryl-3-(3-aryl-1-phenyl-1H-pyrazol-4-yl)prop-2-en-1-ones 6 (pyrazolic chalcones) were synthesized from Claisen-Schmidt reaction of 3-aryl-1-phenylpyrazol-4-carboxaldehydes 4 with several acetophenone derivatives 5. Subsequently, the cyclocondensation reaction of chalcones 6 with phenylhydrazine in acetic acid medium afforded the new 3-aryl-4-(3-aryl-4,5- dihydro-1H-pyrazol-5-yl)-1-phenyl-1H-pyrazoles 7. The synthesized compounds were characterized by spectral studies and evaluated for their in vitro antibacterial activity against three pathogenic bacterial strains, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and in vitro antifungal activity against three pathogenic fungal strains Aspergillus flavus, Chrysosporium keratinophilum, and Candida albicans. © 2012 Springer Science+Business Media New York.Item Click chemistry approach: Regioselective one-pot synthesis of some new 8-trifluoromethylquinoline based 1,2,3-triazoles as potent antimicrobial agents(2014) Garudachari, B.; Isloor, A.M.; Satyanarayana, M.N.; Fun, H.-K.; Hegde, G.Three series of 8-trifluoromethylquinoline based 1,2,3-triazoles derivatives (5a-c, 6a-d and 7a-c) were synthesized by multi-step reactions by click chemistry approach. Synthesized compounds were characterized by spectral studies and X-ray analysis. The final compounds were screened for their in-vitro antimicrobial activity by well plate method (zone of inhibition). Compounds 5c, 6b, 8b, 11 and 12 were found to be active against tested microbial strains. The results are summarized in Tables 5 and 6. © 2014 Elsevier Ltd. All rights reserved.Item Antitubercular and antimicrobial activity of nh4vo3 promoted 1,4-dihydropyridine incorporated 1,3,4-Trisubstituted pyrazole(Bentham Science Publishers B.V. P.O. Box 294 Bussum 1400 AG, 2017) Harikrishna, N.; Isloor, A.M.; Kulal, K.; Parish, T.; Jamalis, J.; Ghabbour, H.A.; Fun, H.-K.Background: A new series of pyrazole containing 1,4-dihydropyridine derivatives 5a-i and 6a-i were synthesized from substituted acetylated aryls and substituted phenylhydrazine by the multistep reaction. Method: The target compounds 1,4-dihydropyridine derivatives were obtained from green synthesis of 1,3-disubstituted phenyl-1H-pyrazole-4-carbaldehydes 4a-i with ethyl acetoacetate and methyl acetoacetate at higher temperatures in the presence of ammonium acetate and the catalytic amount of ammonium metavanadate (NH4VO3). The role of ammonium metavanadate was increases rate of the reaction and obtained high yields. Result: Structures of newly synthesized 1,4-dihydropyridine moiety containing pyrazole derivatives were confirmed by FT-IR, NMR and Mass spectral studies. The structure of compound 5b was confirmed by S-XRD study. Further, these compounds were tested for in-vitro antitubercular and antimicrobial studies. Compounds 5a, 5b, 5i, 6a, 6b, 6g, 6h, and 6i were found to be active against all the bacterial microorganisms. Conclusion: The above mentioned compounds have shown lowest MIC ranging between 3.12-12.5 ?g/ml against Mycobacterium tuberculosis and MIC values ranging between 7.8- 15.6 ?g/ml for Mycobacterium smegmatis, Staphylococcus aureus and Pseudomonas aeruginosa. For the control of life threatening diseases such as tuberculosis, these eight compounds may be strongly promising synthetic compounds. © 2017 Bentham Science Publishers.Item In vitro determination of genotoxicity and cytotoxicity induced by stainless steel brackets with and without surface coating in cultures of oral mucosal cells(BioMed Central Ltd, 2024) Ahuja, D.; Jose, N.P.; Kamal, R.; Panduranga, V.; Nambiar, S.; Isloor, A.M.Background: Orthodontics is a speciality of dentistry that uses a plethora of devices made from myriad materials to manage various malocclusions. Prolonged contact of orthodontic appliances with oral tissues can lead to cellular damage, highlighting the need for biocompatible materials to mitigate health risks. Objectives: To analyze the genotoxicity and cytotoxicity produced by metal brackets and coated metallic brackets with polymeric and nanoparticle coatings in oral mucosal cells. Materials & methods: The current study compares the toxicity of 3 different types of orthodontic brackets with control groups of oral mucosal cells. Each of the three treatment groups consisted of 10 samples of orthodontic brackets: stainless steel brackets(Group 1), nanoparticle-coated brackets(Group 2), and polymeric-coated brackets(Group 3) exposed to corrosion eluates employing an oral biomimicry model. Two types of oral mucosal cells- Human Gingival Fibroblasts and Buccal Epithelial Cells were used to study the cytotoxic and/or genotoxic effects of the elutes. Intergroup comparisons were conducted using one-way analysis of variance, while scanning electron microscopy evaluated surface characteristic. Results: The interaction between metal ions and oral mucosal cells showed no statistically significant difference for toxicity assays between the three groups(p > 0.005). However, polymeric and nanoparticle-coated groups showed reduced cellular differentiation when compared with conventional stainless-steel brackets. Conclusion: This in-vitro study shows that polymeric or nanoparticle coating of conventional metal brackets aids in enhancing corrosion-resistant characteristics of orthodontic appliances and reduces the toxic oral environment created by metal release in the oral cavity. © The Author(s) 2024.