Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Has files: NoSubject: search.filters.subject.antimicrobial activity

Search Results

Now showing 1 - 10 of 21
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Synthesis and antimicrobial activities of novel quinoline derivatives carrying 1,2,4-triazole moiety
    (2009) Eswaran, S.; Vasudeva Adhikari, A.V.; Shetty, N.S.
    A new class of quinoline derivatives containing 1,2,4-triazole moiety were synthesized from derivatives of 4-hydroxy-8-(trifluoromethyl)quinoline-3-carbohydrazide 4 through multi-step reactions. The compound 4, on treatment with substituted Isothiocyanates yielded quinoline-thiosemicarbazides 5a-c, which were conveniently cyclized to (5-mercapto-4H-triazol-3-yl)-quinolin-4-ols 6a-c in basic medium. These intermediates were then transformed to their respective chloro derivatives 7a-c by treatment with phosphorus oxychloride, which on further reaction with different biologically active rare amines yielded the target compounds 8a-g, 9a-h and 10a-h in good yield. The ultimate step, involving nucleophilic substitution reaction was achieved by microwave-induced technique, which has reduced the reaction time drastically as well as improved the yield when compared to conventional heating. The newly synthesized final compounds were evaluated for their in vitro antibacterial and antifungal activities against four strains each. Preliminary results indicated that most of the compounds demonstrated very good antimicrobial activity, comparable to the first line standard drugs. The most effective compounds have exhibited activity at MIC of 6.25 ?g/mL. © 2009 Elsevier Masson SAS. All rights reserved.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Microbial transformation of bioactive natural products
    (2010) Gopkumar, P.; Mugeraya, G.
    In the present study, the fungal biotransformation of 1, 2, 3, 9-tetra hydrpyrrolo [2, 1-b] quinazolin-3-ol (I) is presented. Biocatalysis, isolation and subsequent structure elucidation of the newly transformed metabolite (-)-3-hydroxy -2, 3-dihydro pyrrolo [2, 1-b] quinazoline-9(1H)-one (II) is presented. Microbial transformation of Vasicine (I) by Aspergillus niger, Rhizopus arrhizus, Pencillium notatum and Trematus versicolor afforded (-)-3-hydroxy -2, 3-dihydro pyrrolo [2, 1-b] quinazoline-9(1H)-one (II) (100%) as the sole metabolic product. 1, 2, 3, 9-tetra hydrpyrrolo [2, 1-b] quinazolin-3-ol (I) and (-)-3-hydroxy -2, 3-dihydro pyrrolo [2, 1-b] quinazoline-9(1H)-one (II) screened for antibacterial and antifungal activity.
  • No Thumbnail Available
    Item
    Design, synthesis and antimicrobial activities of some new quinoline derivatives carrying 1,2,3-triazole moiety
    (2010) Thomas, K.D.; Vasudeva Adhikari, A.V.; Shetty, N.S.
    A new series of [1-(6-methoxy-2-methylquinolin-4-yl)-1H-1,2,3-triazol-4-yl] methanamine derivatives were synthesized starting from 4-methoxyaniline through multi-step reactions. The title compounds 5a-y were prepared by treating the azide intermediate 4 with propargyl bromide and different alkyl/heterocyclic amines in a sequential three component synthesis. All the new compounds were characterized by spectral and elemental analyses. The newly synthesized final compounds were evaluated for their in vitro antibacterial and antifungal activities against pathogenic strains. The preliminary screening results indicated that most of the compounds demonstrated moderate to very good antibacterial and antifungal activities, comparable to the first-line drugs. Twenty five new derivatives of [1-(6-methoxy-2-methylquinolin-4-yl)-1H-1,2,3- triazol-4-yl] methanamine have been synthesized and the most effective compounds have MIC of 6.25 ?g/mL, which are in comparable with present antibiotics. © 2010 Elsevier Masson SAS. All rights reserved.
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Hantzsch reaction: Synthesis and characterization of some new 1,4-dihydropyridine derivatives as potent antimicrobial and antioxidant agents
    (2011) Vijesh, A.M.; Isloor, A.M.; Peethambar, S.K.; Shivananda, K.N.; Arulmoli, T.; Isloor, N.
    In the present study two new series of Hantzsch 1,4-dihydropyridine derivatives (1,4-DHPs) containing substituted pyrazole moiety (4a-f and 5a-f) were synthesized by the reaction of 3-aryl-1H-pyrazole-4-carbaldehydes with 1,3-dicarbonylcompounds (ethylacetoacetate and methylacetoacetate) and ammonium acetate. The newly synthesized compounds were characterized by IR, NMR, mass spectral study and also by C, H, N analyses. New compounds were screened for their antimicrobial activity by well plate method (zone of inhibition). Antioxidant studies of the synthesized compounds were also performed by measuring the DPPH radical scavenging assay. Compounds 4c, 4e and 4f were found to be potent antibacterial and antioxidant agents. The acute oral toxicity study for the compounds 4c, 4e and 4f were carried out and the experimental studies revealed that compounds 4c and 4e is safe up to 3000 mg/kg and no death of animals were recorded. However in compound 4f, we found mortality above 2000 mg and also significant behavioral changes in experimental animals. © 2011 Elsevier Masson SAS. All rights reserved.
  • No Thumbnail Available
    Item
    Design, synthesis and docking studies of new quinoline-3-carbohydrazide derivatives as antitubercular agents
    (2011) Thomas, K.D.; Vasudeva Adhikari, A.V.; Telkar, S.; Chowdhury, I.H.; Mahmood, R.; Pal, N.K.; Guru Row, T.N.G.; Sumesh, E.
    Three new series of 4-hydroxy-8-trifluoromethyl-quinoline derivatives were synthesized through multi step reactions. All the newly synthesized compounds were characterized by spectral and elemental analyses. The structure of 5j was evidenced by X-ray crystallographic study. The newly synthesized title compounds were evaluated for their antimicrobial activities including antimycobacterial activity. Amongst the tested compounds, 5b, 5e, 5h, 5j, 6c and 7c displayed promising antimicrobial activity. The mode of action of these active compounds was carried out by docking of receptor enoyl-ACP reductase with newly synthesized candidate ligands, 5b, 5e, 5h, 5j and 6c. © 2011 Elsevier Masson SAS. All rights reserved.
  • No Thumbnail Available
    Item
    Synthesis, characterization and antimicrobial activity of novel ethyl 1-(N-substituted)-5-phenyl-1H-pyrazole-4-carboxylate derivatives
    (2012) Chandrakantha, B.; Isloor, A.M.; Shetty, P.; Isloor, S.; Malladi, S.; Fun, H.-K.
    In the present study, a novel series of Pyrazole derivatives (3a-m) were synthesized by condensing ethyl-3-(dimethylamino)-2-(phenylcarbonyl)prop-2- enoate with different aromatic and aliphatic hydrazines. These newly synthesized compounds were characterized by NMR, mass spectral, IR spectral studies as well as by C, H, and N analyses. All the newly synthesized compounds were screened for their antibacterial properties against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. Among the screened samples, 3c, 3f, 3k, and 3l have showed excellent antibacterial activity against all the tested bacterial strains as compared to the standard drug Ceftriaxone. Few of the compounds were found to be biologically potent. Molecular structure of compound 3i was confirmed by single crystal X-ray analysis. © Springer Science+Business Media, LLC 2011.