Faculty Publications
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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.Item Supramolecular synthons in noncovalent synthesis of a class of gelators derived from simple organic salts: Instant gelation of organic fluids at room temperature via in situ synthesis of the gelators(2009) Das, U.K.; Trivedi, D.R.; Adarsh, N.N.; Dastidar, P.(Chemical Equation Presented) The supramolecular synthon approach has been employed to synthesize noncovalently a series of low molecular mass organic gelators (LMOGs) derived from benzylammonium salts of variously substituted benzoic acids. The majority of the salts (75%) prepared showed interesting gelation properties. Instant gelation of an organic fluid, namely methyl salicylate, was achieved at room temperature by using most of the gelator salts by in situ synthesis of the gelators. Table top rheology and scanning electron microscopy (SEM) were used to characterize the gels. Single crystal X-ray diffraction studies revealed the presence of both 1D and 2D supramolecular synthons. X-ray powder diffraction (XRPD) studies indicated the presence of various crystalline phases in the fibers of the xerogels. By using these data, a structure-property correlation has been attempted and the working hypothesis for designing the gelator has been reinforced. © 2009 American Chemical Society.Item New indole-isoxazolone derivatives: Synthesis, characterisation and in vitro SIRT1 inhibition studies(Elsevier Ltd, 2015) Panathur, N.; Gokhale, N.; Udayakumar, U.; Koushik, P.V.; Yogeeswari, P.; Sriram, D.A new series of indole-isoxazolone hybrids bearing substituted amide, substituted [(1,2,3-triazol-4-yl)methoxy]methyl group or substituted benzylic ether at position-2 of the indole nucleus was synthesised using a facile synthetic route and the molecules were characterised using spectroscopic techniques. The molecules were screened against three human cancer cell lines to evaluate their in vitro cytotoxic property. Most of the trifluoromethyl substituted derivatives exhibited better growth inhibition activity than their methyl substituted analogues. The SIRT1 inhibition activity of two potent molecules (I17 and I18) was investigated and the SIRT1 IC50 values are 35.25 and 37.36 ?M, respectively for I17 and I18. The molecular docking studies with SIRT1 enzyme revealed favourable interactions of the molecule I17 with the amino acids constituting the receptor enzyme. © 2015 Elsevier Ltd. All rights reserved.Item An Efficient Three-component, One-pot Synthesis of Quinazolines under Solvent-free and Catalyst-free Condition(HeteroCorporation support@jhetchem.com, 2015) Bhat, S.I.; Das, U.K.; Trivedi, D.R.An efficient green protocol for the synthesis of quinazolines in the absence of solvent and catalyst has been developed. 2,4-Disubstituted quinazolines have been synthesized from three-component one-pot reactions of 2-aminoaryl ketones, orthoesters, and ammonium acetate. The present method has advantages of operational simplicity, substrate generality, clean reaction, high yields (76-94%), and moderate reaction time. The plausible mechanism of the reaction has been proposed based on the spectral characterization and single crystal X-ray analysis of isolated intermediate. © 2014 HeteroCorporation.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 Production of 5-(formyloxymethyl)furfural from biomass-derived sugars using mixed acid catalysts and upgrading into value-added chemicals(Elsevier Ltd, 2020) Dutta, S.In this work, 5-(formyloxymethyl)furfural (FMF) has been produced from biomass-derived hexose sugars within a biphasic reaction mixture consisting of aqueous formic acid (85%), a strong Brønsted acid catalyst, and 1,2-dichloroethane as an organic extractant. Using a combination of aqueous hydrobromic acid and formic acid, under optimized condition (80 °C, 8 h, 10 wt% substrate loading), 68% isolated yield of FMF was obtained from fructose. FMF has been demonstrated as a renewable chemical building block for the synthesis of renewable chemicals of commercial significance such as 5-methylfurfural, 2,5-diformylfuran, and 2,5-furandicarboxylic acid in good to excellent isolated yields. © 2020 Elsevier LtdItem Polymer-based immobilized Fe2O3–TiO2/PVP catalyst preparation method and the degradation of triclosan in treated greywater effluent by solar photocatalysis(Academic Press, 2021) Pragada, S.C.; Thalla, A.K.The present study involves a novel protocol to develop a ternary composite catalyst for an effective post-treatment technique for greywater. The ternary film of Fe2O3–TiO2/polyvinyl pyrrolidine (PVP) is coated on a glass tube using spray coating with annealing at 320 °C. The structure, thermal, microstructure, and surface properties of the coated film are characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Thermo Gravimetric Analysis (TGA). The scratch hardness of photocatalysts at different Fe2O3/TiO2 compositions is investigated based on the width measurement of scratch using FESEM analysis. Results show that at an optimum coating of 5% of Fe2O3/TiO2 composition catalytic film, the maximum scratch hardness (7.984 GPa) is obtained. Also, the photocatalyst has the highest cohesive bond strength and wearing resistance. The degradation of triclosan (TCS) in treated greywater, discharged from the anaerobic-aerobic treatment system, is investigated at a lab-scale using a solar photocatalytic reactor. The response surface analysis has been performed from the different sets of experimental trials for various optimal parameters. It is observed that the TCS degradation efficiency of 83.27% has resulted under optimum conditions. © 2021 Elsevier LtdItem The role of solvent soaking and pretreatment temperature in microwave-assisted pyrolysis of waste tea powder: Analysis of products, synergy, pyrolysis index, and reaction mechanism(Elsevier Ltd, 2022) Talib Hamzah, H.; Sridevi, V.; Seereddi, M.; Suriapparao, D.V.; Ramesh, R.; Sankar Rao, C.S.; Gautam, R.; Kaka, F.; Pritam, K.This study focuses on microwave-assisted pyrolysis (MAP) of fresh waste tea powder and torrefied waste tea powder as feedstocks. Solvents including benzene, acetone, and ethanol were used for soaking feedstocks. The feedstock torrefaction temperature (at 150 °C) and solvents soaking enhanced the yields of char (44.2–59.8 wt%) and the oil (39.8–45.3 wt%) in MAP. Co-pyrolysis synergy induced an increase in the yield of gaseous products (4.7–20.1 wt%). The average heating rate varied in the range of 5–25 °C/min. The energy consumption in MAP of torrefied feedstock (1386 KJ) significantly decreased compared to fresh (3114 KJ). The pyrolysis index dramatically varied with the solvent soaking in the following order: ethanol (26.7) > benzene (25.6) > no solvent (10) > acetone (6). It shows that solvent soaking plays an important role in the pyrolysis process. The obtained bio-oil was composed of mono-aromatics, poly-aromatics, and oxygenated compounds. © 2022 Elsevier LtdItem Metal-Free Bisamidation of N-Tosylhydrazones with Carboxylic Acids Promoted by Tetrabutylammonium Iodide and tert-Butyl Hydroperoxide(American Chemical Society, 2024) Shamnad, A.; Nayak, K.H.; Babu, B.P.A versatile reaction between N-tosylhydrazones and carboxylic acids to access bisamides is reported. This metal-free, room-temperature reaction was catalyzed by TBAI, while TBHP served as the oxidant. Broad substrate scope and good functional group tolerance are the key features of the strategy. Subsequent intramolecular N-arylation of suitably substituted bisamides readily afforded functionalized 3-indazolones. © 2024 American Chemical Society