Faculty Publications
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Item Identification and characterization of novel indole based small molecules as anticancer agents through SIRT1 inhibition(2013) Panathur, N.; Udayakumar, U.; Koushik, P.V.; Alvala, M.; Yogeeswari, P.; Sriram, D.; Kumar, V.In our pursuit to develop new potential anticancer leads, we designed a combination of structural units of indole and substituted triazole; and a library of 1-{1-methyl-2-[4-phenyl-5-(propan-2-ylsulfanyl)-4H-1,2,4-triazol-3- yl]-1H-indol-3-yl}methanamine derivatives was synthesized and characterized. Cytotoxic evaluations of these molecules over a panel of three human cancer cell lines were carried out. Few molecules exhibited potent growth inhibitory action against the treated cancer cell lines at lower micro molar concentration. An in vitro assay investigation of these active compounds using recombinant human SIRT1 enzyme showed that one of the compounds (IT-14) inhibited the deacetylation activity of the enzyme. The in vivo study of IT-14 exemplified its promising action by reducing the prostate weight to the body weight ratio in prostate hyperplasia animal models. A remarkable decrease in the disruption of histoarchitecture of the prostate tissues isolated from IT-14 treated animal compared to that of the positive control was observed. The molecular interactions with SIRT1 enzyme were also supported by molecular docking simulations. Hence this compound can act as a lead molecule to treat prostatic hyperplasia. © 2013 Elsevier Masson SAS. All rights reserved.Item Synthesis and biological evaluation of new imidazo[2,1-b][1,3,4]thiadiazole-benzimidazole derivatives(Elsevier Masson SAS infos@masson.fr 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2015) Ramprasad, J.; Nayak, N.; Udayakumar, U.; Yogeeswari, P.; Sriram, D.; Peethambar, S.K.; Achur, R.; Santosh Kumar, H.S.S.In this report, we describe the synthesis and biological evaluation of a new series of 2-(imidazo[2,1-b][1,3,4]thiadiazol-5-yl)-1H-benzimidazole derivatives (5a-ac). The molecules were analyzed by 1H NMR, 13C NMR, mass spectral and elemental data. The structure of one of the pre-final compounds, 6-(4-methoxyphenyl)-2-(4-methylphenyl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde (4d) and that of a target compound, 2-[2-methyl-6-(4-methyl phenyl) imidazo[2,1-b][1,3,4]thiadiazol-5-yl]-1H-benzimidazole (5aa) were confirmed by single crystal XRD studies. All the target compounds were screened for in vitro anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv strain. Seven (5c, 5d, 5l, 5p, 5r, 5z and 5aa) out of twenty nine compounds showed potent anti-tubercular activity with a MIC of 3.125 ?g/mL. A p-substituted phenyl group (p-tolyl or p-chlorophenyl) in the imidazo[2,1-b][1,3,4]thiadiazole ring and/or a chloro group in the benzimidazole ring enhance anti-tuberculosis activity whereas a nitro group in the benzimidazole ring reduces the activity. In the antibacterial screening, compounds 5i, 5w and 5ac showed promising activity against the tested bacterial strains. Further, antifungal and antioxidant activities of these molecules were also investigated. In the cytotoxicity study, the active antitubercular compounds exhibited very low toxicity against a normal cell line. © 2015 Elsevier Masson SAS.Item One-pot synthesis of new triazole - Imidazo[2,1-b][1,3,4]thiadiazole hybrids via click chemistry and evaluation of their antitubercular activity(Elsevier Ltd, 2015) Ramprasad, J.; Nayak, N.; Udayakumar, U.; Yogeeswari, P.; Sriram, D.A new series of triazole-imidazo[2,1-b][1,3,4]thiadiazole hybrids (6a-s, 7a) were designed by a molecular hybridisation approach and the target molecules were synthesized via one pot click chemistry protocol. All the intermediates and final molecules were characterised using spectral methods and one of the target compounds (6c) was analysed by the single crystal XRD study. The derivatives were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv strain. Two compounds, 6f and 6n, demonstrated significant growth inhibitory activity against the bacterial strain with a MIC of 3.125 ?g/mL. The presence of chloro substituent on the imidazo[2,1-b][1,3,4]thiadiazole ring and ethyl, benzyl or cyanomethylene groups on the 1,2,3-triazole ring enhance the inhibition activity of the molecules. The active compounds are not toxic to a normal cell line which signifies the lack of general cellular toxicity of these compounds. © 2015 Elsevier Ltd. All rights reserved.Item New INH-pyrazole analogs: Design, synthesis and evaluation of antitubercular and antibacterial activity(Elsevier Ltd, 2015) Nayak, N.; Ramprasad, J.; Udayakumar, U.With the aim of developing promising antitubercular and antibacterial leads, we have designed and synthesized a new series of isonicotinohydrazide based pyrazole derivatives (5a-r). All new derivatives (4a-b and 5a-r) were screened for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) strain. Four compounds 5j, 5k, 5l and 4b emerged as promising antitubercular agents with MIC of ?4.9 ?M which is much lower than the MIC of the first line antitubercular drug, ethambutol. The 3-chlorophenyl substituent at position-3 of the pyrazole ring enhanced the antiTB activity of the molecules. Three derivatives 5b, 5k and 4b exhibited promising antibacterial activity against the tested bacterial strains. The active molecules were nontoxic to normal Vero cells and showed high selectivity index (>160). The structure and antitubercular activity relationship was further supported by in silico molecular docking study of the active compounds against enoyl acyl carrier protein reductase (InhA) enzyme of M. tuberculosis. © 2015 Published by Elsevier Ltd.Item Design of new phenothiazine-thiadiazole hybrids via molecular hybridization approach for the development of potent antitubercular agents(Elsevier Masson SAS 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2015) Ramprasad, J.; Nayak, N.; Udayakumar, U.A new library of phenothiazine and 1,3,4-thiadiazole hybrid derivatives (5a-u) was designed based on the molecular hybridization approach and the molecules were synthesized in excellent yields using a facile single-step chloro-amine coupling reaction between 2-chloro-1-(10H-phenothiazin-10-yl)ethanones and 2-amino-5-subsituted-1,3,4-thiadiazoles. The compounds were evaluated for their in vitro inhibition activity against Mycobacterium tuberculosis H37Rv (MTB). Compounds 5g and 5n were emerged as the most active compounds of the series with MIC of 0.8 ?g/mL (?1.9 ?M). Also, compounds 5a, 5b, 5c, 5e, 5l and 5m (MIC = 1.6 ?g/mL), and compounds 5j, 5k and 5o (MIC = 3.125 ?g/mL) showed significant inhibition activity. The structure-activity relationship demonstrated that an alkyl (methyl/npropyl) or substituted (4-methyl/4-Cl/4-F) phenyl groups on the 1,3,4-thiadiazole ring enhance the inhibition activity of the compounds. The cytotoxicity study revealed that none of the active molecules are toxic to a normal Vero cell line thus proving the lack of general cellular toxicity. Further, the active molecules were subjected to molecular docking studies with target enzymes InhA and CYP121. © 2015 Elsevier Masson SAS. All rights reserved.Item Design, Synthesis, and Biological Evaluation of New 8-Trifluoromethylquinoline Containing Pyrazole-3-carboxamide Derivatives(HeteroCorporation, 2017) Nayak, N.; Ramprasad, J.; Udayakumar, U.The article describes the design, synthesis, and characterization of a new series of 8-trifluoromethylquinoline substituted pyrazole-3-carboxamides (9a, 9b, 9c, 9d, 9e, 9f, 9g, 9h, 9i, 9j, 9k, 9l, 9m, 9n, 9o, 9p, 9q, 9r, 9s, 9t) derived from different primary and secondary amines. The intermediate and target compounds were characterized using spectroscopic methods. The structures of intermediate 7 and target molecule 9d were evidenced by the single crystal X-ray study. All the synthesized target compounds (9a, 9b, 9c, 9d, 9e, 9f, 9g, 9h, 9i, 9j, 9k, 9l, 9m, 9n, 9o, 9p, 9q, 9r, 9s, 9t) and three intermediates (6, 7, 8) were screened for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv strain. Two compounds, 9k and 9t, showed significant inhibition activity with MIC of 3.13 µg/mL, which is comparable with the activity of standard drug, ethambutol. The carboxamides derived from benzylamine derivatives were more active than their aniline analogs. In general, the hybrid amides with a N-methylene linkage (-CONHCH2-) exhibited enhanced antitubercular activity. In the antibacterial screening, intermediate 3-hydrazinyl-2-methyl-8-(trifluoromethyl)quinoline (6) displayed remarkable activity against the tested bacterial strains. Further, the active anti-TB derivatives were non-toxic to benign NIH 3T3 cells, which demonstrate the lack of general cellular toxicity and hence signifies their suitability for further lead development. © 2015 HeteroCorporationItem Structural modification of zolpidem led to potent antimicrobial activity in imidazo[1,2-: A] pyridine/pyrimidine-1,2,3-triazoles(Royal Society of Chemistry, 2019) Reddyrajula, R.; Udayakumar, U.Ambien (zolpidem), an imidazo[1,2-a]pyridine derivative, is a commercial drug to treat insomnia which also possesses antitubercular activity against Mycobacterium tuberculosis H37Rv. In this paper, we describe the synthesis of three diverse lead series of imidazo[1,2-a]pyridine/pyrimidine-1,2,3-triazoles (IPTs) which are designed by specific structural modifications of zolpidem. Most of the IPTs exhibited remarkable in vitro antitubercular activity with an MIC of 1.56 ?g mL-1, which is two-fold higher than the MIC of zolpidem. Further, the synthesized IPTs displayed moderate inhibitory activity against several bacterial and fungal strains as well, and also showed an acceptable safety profile as verified through in vitro cytotoxicity assessment against Vero cells. In addition, the potent IPTs exhibited promising binding interactions within the active site of the InhA enzyme. An interesting correlation between the in vitro inhibitory activity and the binding mode was observed: most of the potent molecules (MIC = 1.56 ?g mL-1) interact through a H-bond with the Tyr 158 residue of the target enzyme. These efforts toward the structural modification of zolpidem could be helpful for further optimization of the IPT core to develop new anti-TB drugs. This journal is © 2019 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.Item Molecular hybridization approach for phenothiazine incorporated 1,2,3-triazole hybrids as promising antimicrobial agents: Design, synthesis, molecular docking and in silico ADME studies(Elsevier Masson SAS 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2019) Reddyrajula, R.; Udayakumar, U.; Madan Kumar, S.The objective of the current study is to synthesize a library consisting of four sets of phenothiazine incorporated 1,2,3-triazole compounds using molecular hybridization approach. In total, 36 new hybrid molecules were synthesized and screened for in vitro growth inhibition activity against Mycobacterium tuberculosis H37Rv strain (ATCC-27294). Among the tested compounds, nineteen compounds exhibited significant activity with MIC value 1.6 ?g/mL, which is twofold higher than the MIC value of standard first-line TB drug Pyrazinamide. In addition, all these compounds are proved to be non-toxic (with selective index > 40) against VERO cell lines. However, these compounds did not inhibit significantly the growth of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa strains: the activity profile is similar to that observed for standard anti-TB drugs (isoniazid and pyrazinamide), indicating the specificity of these compounds towards the Mycobacterium tuberculosis strain. Also, we report the molecular docking studies against two target enzymes (Inh A and CYP121) to further validate the antitubercular potency of these molecules. Furthermore, prediction of in silico-ADME and pharmacokinetic parameters indicated that these compounds have good oral bioavailability. The results suggest that these phenothiazine incorporated 1,2,3-triazole compounds are a promising class of molecular entities for the development of new antitubercular leads. © 2019 Elsevier Masson SASItem The bioisosteric modification of pyrazinamide derivatives led to potent antitubercular agents: Synthesis via click approach and molecular docking of pyrazine-1,2,3-triazoles(Elsevier Ltd, 2020) Reddyrajula, R.; Udayakumar, U.Tuberculosis remains as a major public health risk which causes the highest mortality rate globally and an improved regimen is required to treat the drug-resistant strains. Pyrazinamide is a first-line antitubercular drug used in combination therapy with other anti-TB drugs. Herein, we describe the modification of pyrazinamide structure using bioisosterism and rational approaches by incorporating the 1,2,3-triazole moiety. Three sets of pyrazine-1,2,3-triazoles (3a-o, 5a-o and 9a-l) are designed, synthesized and evaluated for their in vitro inhibitory potency against mycobacterium tuberculosis H37Rv. The pyrazine-1,2,3-triazoles synthesized through the bioisosteric modification displayed improved activity as compared to rationally modified pyrazine-1,2,3-triazoles. Among 42 title compounds, seven derivatives demonstrated significant anti-tubercular activity with the MIC of 1.56 ?g/mL, which are two-fold more potent than the parent compound pyrazinamide. Further, the synthesized pyrazinamide analogs demonstrated moderate inhibition activity against several bacterial strains and possessed an acceptable in vitro cytotoxicity profile as well. Additionally, the activity profile of pyrazine-1,2,3-triazoles was validated by performing the molecular docking studies against the Inh A enzyme. Furthermore, in silico ADME prediction revealed good oral bioavailability for the potent molecules. © 2019 Elsevier LtdItem Discovery of 1,2,3-triazole incorporated indole-piperazines as potent antitubercular agents: Design, synthesis, in vitro biological evaluation, molecular docking and ADME studies(Elsevier Ltd, 2024) Reddyrajula, R.; Etikyala, U.; Vijjulatha, V.; Udayakumar, U.In this report, a library consisting of three sets of indole-piperazine derivatives was designed through the molecular hybridization approach. In total, fifty new hybrid compounds (T1-T50) were synthesized and screened for antitubercular activity against Mycobacterium tuberculosis H37Rv strain (ATCC-27294). Five (T36, T43, T44, T48 and T49) among fifty compounds exhibited significant inhibitory potency with the MIC of 1.6 µg/mL, which is twofold more potent than the standard first-line TB drug Pyrazinamide and equipotent with Isoniazid. N-1,2,3-triazolyl indole-piperazine derivatives displayed improved inhibition activity as compared to the simple and N-benzyl indole-piperazine derivatives. In addition, the observed activity profile of indole-piperazines was similar to standard anti-TB drugs (isoniazid and pyrazinamide) against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa strains, demonstrating the compounds’ selectivity towards the Mycobacterium tuberculosis H37Rv strain. All the active anti-TB compounds are proved to be non-toxic (with IC50 > 300 μg/mL) as verified through the toxicity evaluation against VERO cell lines. Additionally, molecular docking studies against two target enzymes (Inh A and CYP121) were performed to validate the activity profile of indole-piperazine derivatives. Further, in silico-ADME prediction and pharmacokinetic parameters indicated that these compounds have good oral bioavailability. © 2023 Elsevier Ltd