Faculty Publications

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Publications by NITK Faculty

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Author: search.filters.author.Isloor, A.M.Subject: search.filters.subject.article

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    Regioselective reaction: Synthesis, characterization and pharmacological studies of some new Mannich bases derived from 1,2,4-triazoles
    (2009) Isloor, A.M.; Kalluraya, B.; Shetty, P.
    In the present investigation, a series of new 4[(3-substituted-1H-pyrazol-4-yl)methyleneamino]-5-substituted-2-[(4-methylpiperzine-1-yl)methyl]-2H-1,2,4-triazole-3(4H)-thiones (4) were synthesized by the aminomethylation of 4-(3-substituted-1H-pyrazol-3-yl)methyleneamino-5-substituted-4H-1,2,4-triazole-3-thiols (3) with formaldehyde and N-methylpiperzine. These newly synthesized Schiff and Mannich bases were characterized by IR, 1H NMR, mass spectral data and elemental analyses. These compounds were screened for their antibacterial and antifungal activity. Some of the compounds were found to exhibit significant antimicrobial activity. © 2009 Elsevier Masson SAS. All rights reserved.
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    Synthesis, characterization and biological activities of some new benzo[b]thiophene derivatives
    (2010) Isloor, A.M.; Kalluraya, B.; Pai, K.
    Benzo[b]thiophene molecules are found to be important tools in synthetic medicinal chemistry. They are of current interest due to their wide spectrum of pharmacological properties. In view of the biological activities of benzo[b]thiophene containing molecules, in this present research work, we propose the synthesis of some new benzo[b]thiophene derivatives such as thiadiazoles, oxadiazoles, pyrazolin & diaryl pyrazoles starting from 3-chlorobenzo[b]thiophene-2-carboxyl chloride. These newly synthesized compounds were characterized by elemental analyses, I.R, NMR and Mass spectral studies. Some of the selected compounds were screened for their antibacterial, antifungal and anti-inflammatory studies. Many of the molecules were found to be potent. © 2009 Elsevier Masson SAS. All rights reserved.
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    Synthesis, characterization and biological activity of some new 1,3,4-oxadiazole bearing 2-flouro-4-methoxy phenyl moiety
    (2010) Chandrakantha, B.; Shetty, P.; Nambiyar, V.; Isloor, N.; Isloor, A.M.
    In the present study a series of new 1,3,4-oxadiazole derivatives containing 2-fluoro-4-methoxy moiety were synthesized. These newly synthesized compounds were characterized by NMR, mass spectral, IR spectral study and also by C, H, N analyses. All the newly synthesized compounds were screened for their antibacterial and antifungal studies. Antimicrobial studies revealed that compounds 4a and 4b showed significant antibacterial activity against Escherichia coli and Pseudomonas aeruginosa Compound 4i showed significant antifungal activity against C. albicans. © 2009 Elsevier Masson SAS. All rights reserved.
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    Novel chromeno [2,3-b]-pyrimidine derivatives as potential anti-microbial agents
    (2010) Sankappa Rai, U.; Isloor, A.M.; Shetty, P.; Vijesh, A.M.; Prabhu, N.; Isloor, S.; Thiageeswaran, M.; Fun, H.-K.
    An efficient, microwave irradiated synthesis of novel chromeno[2,3-b]-pyrimidine derivatives was carried out. 2-Amino-3,4-dihydro-2H-chromene-3-carbonitrile was converted into imine using N,N-Dimethylacetaldehyde dimethylacetal to give the core intermediate, which was used for the preparation of chromenopyrimidine library, using acetic acid and different amine in microwave irradiation for 5 min. Structures of newly synthesized compounds were confirmed by spectral studies. Compound 6g was characterized by single crystal X-ray analysis. All the compounds were also screened for their anti-microbial activity. Few of the compounds are found to be potential antimicrobials. © 2010 Elsevier Masson SAS. All rights reserved.
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    Synthesis, characterization and anti-microbial studies of some novel 2,4-disubstituted thiazoles
    (2010) Vijesh, A.M.; Isloor, A.M.; Prabhu, V.; Ahmad, S.; Malladi, S.
    In the present study a series of novel 2,4-disubstituted thiazole derivatives containing substituted pyrazole moiety was synthesized by the reaction of 3-Aryl-1H-pyrazole-4-carbaldehyde thiosemicarbazone with 6-Bromo/H-3-(bromoacetyl)-2H-chromen-2-one/phenacyl chloride. Structures of newly synthesized compounds were characterized by spectral studies. New compounds were screened for their antibacterial studies against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The results revealed that compounds 7c, 8e, and 8f having 2,5-dichlorothiophene substituent and 8c, 8d having 2,4-dichlorophenyl substituent showed significant antibacterial activity against all tested microorganisms. © 2010 Elsevier Masson SAS. All rights reserved.
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    Synthesis and biological evaluation of aminoketones
    (2010) Sankappa Rai, U.; Isloor, A.M.; Shetty, P.; Isloor, N.; Malladi, S.; Fun, H.-K.
    A three-component Mannich reaction of different ketones with aromatic aldehydes and different amines in microwave irradiation under solvent free condition afforded corresponding ?-amino carbonyl compounds in excellent yields. This method proved as a novel and improved modification of the reported three-component Mannich reaction in terms of milder reaction conditions, reaction times, clean reaction profiles, very small quantity of catalyst and simple workup procedure. Newly synthesized ?-aminoketones were characterized by spectral studies. Structure of compound 4a was also confirmed by single-crystal X-ray analysis. All the compounds were screened for their antimicrobial activity by MIC method. Few of the molecules were found to be biologically potent. © 2010 Elsevier Masson SAS. All rights reserved.
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    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.
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    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.
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    Synthesis, characterization, antioxidant, and anticancer studies of 6-[3-(4-chlorophenyl)-1H-pyrazol-4-yl]-3-[(2-naphthyloxy) methyl][1,2,4] triazolo[3,4-b][1,3,4]thiadiazole in HepG2 cell lines
    (2011) Dhanya, D.; Isloor, A.M.; Shetty, P.; Satyamoorthy, K.; Prasad, A.S.B.
    Triazolo- thiadiazoles exhibit a variety of pharmacological properties, due to their cytotoxicity. In continuation of a previous study on triazolo-thiadiazoles, the authors have synthesized a new thiadiazole, 6-[3-(4-chlorophenyl)- 1-H-pyrazol-4-yl]-3-[(2-naphthyloxy)methyl] [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole (CPNT), which was further characterized by advanced spectral techniques and elemental analysis. The compound exhibited a dose-dependent cytotoxic effect on hepatocellular carcinoma cell line, HepG2 with very low IC50 value of 0.8 ?g/ml in 24 h when compared with standard drug, doxorubicin. Incorporation of [3H] thymidine in conjunction with cell cycle analysis suggested that CPNT inhibited the growth of HepG2 cells. Flow cytometric studies revealed more percentage of cells in subG1 phase, indicating apoptosis, which was further confirmed through chromatin condensation studies by Hoechst staining. In vitro antioxidant activity of CPNT was determined by DPPH and ABTS free radical scavenging assays which revealed increasing scavenging activity with increasing concentration of the compound when compared with reference ascorbic acid. © Springer Science+Business Media, LLC 2010.
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    Synthesis of some new pyrazolone derivatives as potent antimicrobial agents
    (2011) Vijesh, A.M.; Isloor, A.M.; Isloor, S.; Shivananda, K.N.; Shyma, P.C.; Arulmoli, T.
    Invasive microbial infections are major problems around the world, especially in immuno compromised patients. The recent expansion of antimicrobial drug research has occurred because there is a critical need for new antimicrobial agents to treat these life threatening invasive infections. In the present study three series of new substituted pyrazolone derivatives (5a-f, 6a-f and 8a,b) were synthesized by the Knoevenagel condensation reaction of pyrazolones (3a,b) with various substituted carbaldehydes (4a-f, 7). These newly synthesized compounds were characterized by IR, NMR, mass spectra and also by C, H, N analyses. New compounds were screened for their antimicrobial studies against S. aureus, B. subtilis, E. coli and P. aeruginosa. The results revealed that compounds 5c and 6c having 2,5-dichlorothiophene substituent showed significant antibacterial activity against all tested microorganisms as compared to the standard drug Ceftriaxone.