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 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.Item 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.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 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 Preparation of gold nanoparticles by novel bacterial exopolysaccharide for antibiotic delivery(Elsevier Inc. usjcs@elsevier.com, 2016) Pradeepa, n.; Vidya, S.M.; Mutalik, S.; Bhat, K.U.; Huilgol, P.; Avadhani, K.Aim To develop potent drug delivery agents to treat multidrug resistant (MDR) bacterial infections using gold nanoparticles (AuNPs) prepared by bacterial exopolysaccharide (EPS) being a reducing and stabilizing agent. Methods Gold nanoparticles were prepared by EPS, extracted from Lactobacillus plantarum. AuNPs were characterized by UV-visible spectrophotometer, transmission electron microscope (TEM), zeta potential and Fourier transform infrared spectroscopy. Antibiotics used for functionalization of AuNPs were levofloxacin, cefotaxime, ceftriaxone and ciprofloxacin. The resulted functionalized AuNPs were tested against various MDR bacteria by employing different assays such as well diffusion assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time killing assay. Key findings The nanostructures exhibited excellent bactericidal activity and reduced MIC and MBC against MDR Gram positive and Gram negative bacteria compared to free drugs. Escherichia coli was the most susceptible MDR bacteria followed by Klebsiella pneumoniae and Staphylococcus aureus. TEM results revealed that the bactericidal activity of nanostructures could be mediated by penetration, loss of cytoplasmic contents and cell lysis. Significance Antibiotic functionalized nanostructures were more potent than free drugs and could be used as potent drug delivery vehicles. © 2016 Elsevier Inc. All rights reserved.