Faculty Publications
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Publications by NITK Faculty
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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.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, 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.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 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 New pyrazole derivatives containing 1,2,4-triazoles and benzoxazoles as potent antimicrobial and analgesic agents(2013) Vijesh, A.M.; Isloor, A.M.; Shetty, P.; Sundershan, S.; Fun, H.-K.Azole class of compounds are well known for their excellent therapeutic properties. Present paper describes about the synthesis of three series of new 1,2,4-triazole and benzoxazole derivatives containing substituted pyrazole moiety (11a-d, 12a-d and 13a-d). The newly synthesized compounds were characterized by spectral studies and also by C, H, N analyses. All the synthesized compounds were screened for their analgesic activity by the tail flick method. The antimicrobial activity of the new derivatives was also performed by Minimum Inhibitory Concentration (MIC) by the serial dilution method. The results revealed that the compound 11c having 2,5-dichlorothiophene substituent on pyrazole moiety and a triazole ring showed significant analgesic and antimicrobial activity. © 2012 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 Probing the morphology and anti-organic fouling behaviour of a polyetherimide membrane modified with hydrophilic organic acids as additives(Royal Society of Chemistry, 2015) Hebbar, R.S.; Isloor, A.M.; A.F., A.F.; Shilton, S.J.; AlObaid, A.; Fun, H.-K.A facile approach for the preparation of an organic antifouling polymer membrane has been developed using low molecular weight organic acids as additives. The presence of these additives in the membrane was analysed by FTIR spectroscopy. The properties of the modified membranes were investigated in terms of contact angle, water uptake capacity, SEM and AFM analysis. These additives exerted a strong impact on the rheological properties of the casting solution, thereby altering the membrane morphology, surface roughness, water flux and the hydrophilicity of the membranes, as compared to those of the pristine polyetherimide (PEI) membrane. The organic antifouling properties of the modified membrane were analysed by filtering both bovine serum albumin (BSA) and humic acid solutions. The results showed that the additives exhibited a remarkable improvement in the antifouling properties (FRR of 72%) and a humic acid rejection of up to 86%. These outcomes offer new insights into the use of cheaper and readily available organic acids as additives, compared to the traditional, synthetic polymer materials as additives in membrane preparation. ©2015 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.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.