It is of interest to list plants and its usage in olden days. The history of plants is closely related with the history of medicine since time immemorial. Various literature data shows the usage of medicinal plants.
View Article and Find Full Text PDFThe present study explores the production, characterization, and application of a potentially stable melanin precursor from marine imperfect non-spore-forming Aspergillus nidulans sp. strain SG 28. Growth of the culture in artificial seawater with galactose and monosodium glutamate, pH at 7.
View Article and Find Full Text PDFChromium-induced toxicity and mechanisms of cell death involved in plants are yet to be fully elucidated. To understand the events of these processes, the stress response of the soybean plant using trivalent and hexavalent chromium compounds, namely, basic chromium sulphate (BCS) and potassium dichromate (KCrO) was investigated. The leaf surface morphology for stomatal aperture, wax deposition and presence of trichomes for chromium accumulation was examined by SEM-EDAX and light microscopy.
View Article and Find Full Text PDFA series of novel dibenzo[b,d]thiophene tethered imidazo[1,2-a]pyridine carboxamides 7a-s were designed and synthesized. The required building block, 2-dibenzo[b,d]thiophenyl imidazo[1,2-a]pyridine carboxylic acid (5) was synthesized from commercial dibenzo[b,d]thiophene in good yields following five-step reaction sequence. The desired carboxamides 7a-s was prepared through coupling of acid 5 with various benzyl amines.
View Article and Find Full Text PDFJ Indian Prosthodont Soc
May 2016
Background: A common problem faced by prosthodontists is achieving adequate retention and stability in the mandibular dentures. Recording the lateral throat form (LTF) correctly can aid in the retention and stability. Till date, Neil's classification has been considered as the gold standard in measuring the depth of the LTF.
View Article and Find Full Text PDF2-Styrylquinazolones are reported as a novel class of potent anti-mycobacterial agents. Forty-six target compounds have been synthesized using one pot reaction involving isatoic anhydride, amine, and triethyl orthoacetate followed by aldehyde to construct the 2-styrylquinazolone scaffold. The anti-mycobacterial potency of the compounds was determined against H37Rv strain.
View Article and Find Full Text PDFThe benzo[d]thiazol-2-yl(piperazin-1-yl)methanones scaffold has been identified as new anti-mycobacterial chemotypes. Thirty-six structurally diverse benzo[d]thiazole-2-carboxamides have been prepared and subjected to assessment of their potential anti-tubercular activity through in vitro testing against Mycobacterium tuberculosis H37Rv strain and evaluation of cytotoxicity against RAW 264.7 cell lines.
View Article and Find Full Text PDFBackground And Objectives: Bacterial DNA topoisomerases are unique in maintaining the DNA topology for cell viability. Mycobacterium tuberculosis (MTB) DNA gyrase, a sole type II topoisomerase has a larger scope as a target for developing novel therapeutics. In this study, an effort was made towards the design and synthesis of benzothiazinone-piperazine hybrid analogues to obtain the possibility of it to lead development through the molecular hybridization technique.
View Article and Find Full Text PDFIntroduction: Mycobacterium marinum has emerged as a suitable species for induction of tuberculosis-like disease in zebrafish, and various zebrafish models (larval and adult) for drug screening have been proposed in the literature. It is believed that an adult zebrafish model is more useful in drug screening because, apart from assessment of efficacy, one can obtain data on dosage, pharmacokinetics and overall health improvement. This study suggests a simple, cost-effective and resource-efficient protocol for screening of anti-tuberculosis drugs.
View Article and Find Full Text PDFMycobacterial DNA gyrase B subunit has been identified to be one of the potentially underexploited drug targets in the field of antitubercular drug discovery. In the present study, we employed structural optimization of the reported GyrB inhibitor resulting in synthesis of a series of 46 novel quinoline derivatives. The compounds were evaluated for their in vitro Mycobacterium smegmatis GyrB inhibitory ability and Mycobacterium tuberculosis DNA supercoiling inhibitory activity.
View Article and Find Full Text PDFMycobacterium tuberculosis (MTB) has remarkable ability to persist in the human host and causes latent infection in one third of the world population. Currently available tuberculosis (TB) drugs while effective in killing actively growing MTB, is largely ineffective in killing persistent or latent MTB. Lysine-ɛ aminotransferase (LAT) enzyme is reported to be highly up-regulated (41.
View Article and Find Full Text PDFBioorg Med Chem Lett
September 2015
Natural alkaloid, tryptanthrin (indolo[2,1-b]quinazoline-6,12-dione) and its analogues are found to exhibit potent anti-tubercular activity against MDR-TB. A novel class of indolo[2,1-b]quinazolinones have been synthesized to evaluate their anti-mycobacterial activity. Enoyl-acyl carrier protein reductase (InhA) of Mycobacterium tuberculosis is one of the key enzymes and has been validated as an effective anti-microbial target.
View Article and Find Full Text PDFAntibiotics with good therapeutic value and novel mechanism of action are becoming increasingly important in today's battle against bacterial resistance. One of the popular targets being DNA gyrase, is currently becoming well-established and clinically validated for the development of novel antibacterials. In the present work, a series of forty eight quinoline-aminopiperidine based urea and thiourea derivatives were synthesized as pharmacophoric hybrids and evaluated for their biological activity.
View Article and Find Full Text PDFMycobacterium tuberculosis (Mtb) topoisomerase I (Topo I), involved in the relaxation of negatively supercoiled DNA, plays an important role in the viability of pathogen Mtb. Being one of the most significant enzymes; it also takes part in crucial biological pathways such as transcription and replication of the pathogen. The present study aims at the development of Mtb Topo I 3D protein structure which in turn was employed for the virtual screening of compound libraries in a process of identification of a hit molecule.
View Article and Find Full Text PDFDNA gyrase is the only type II topoisomerase in Mycobacterium tuberculosis (Mtb), unlike other bacteria and its absence in human being makes it a clinically validated target for developing anti-tubercular leads against Mtb. In the present study, our effort was to optimize and synthesize a series of compounds by a combination of molecular docking, and synthetic chemistry approach for better activity. A series of twenty eight substituted 2-amino-5-phenylthiophene-3-carboxamide derivatives were designed based on our earlier reported Mtb GyrB inhibitor lead.
View Article and Find Full Text PDFPantothenate synthetase (PS) enzyme involved in the pantothenate biosynthetic pathway is essential for the virulence and persistent growth of Mycobacterium tuberculosis (MTB). It is encoded by the panC gene, and has become an appropriate target for developing new therapeutics for tuberculosis. Here we report new inhibitors active against MTB PS developed using energy based pharmacophore modelling of the available proteininhibitor complex (3IVX) and virtual screening of a large commercial library.
View Article and Find Full Text PDFIn the present study, we used crystal structure of MTB L-AlaDH protein complex with N6-methyl adenosine for structure based virtual screening of in house database to identify new small molecule inhibitors for MTB-L-AlaDH. Two molecules identified as better leads and were modified synthetically to obtain thirty novel analogues belonging to 2-iminothiazolidine-4-ones and 4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxamides. Among the screened compounds four (4n, 4o, 12 and 14) emerged as potent inhibitors displaying IC50 values ranging from 0.
View Article and Find Full Text PDFOrg Biomol Chem
February 2015
DNA gyrase, the sole type II topoisomerase present in Mycobacterium tuberculosis, is absent in humans and is a well validated target for anti-tubercular drug discovery. In this study, a moderately active inhibitor of Mycobacterium tuberculosis GyrB, the pharmaceutically unexploited domain of DNA gyrase, was reengineered using a combination of molecular docking and medicinal chemistry strategies to obtain a lead series displaying considerable in vitro enzyme efficacy and bacterial kill against the Mycobacterium tuberculosis H37Rv strain. Biophysical investigations using differential scanning fluorimetry experiments re-ascertained the affinity of these molecules towards the GyrB domain.
View Article and Find Full Text PDFGyrase ATPase domain, the pharmaceutical underexploited segment of DNA gyrase, the sole Type II topoisomerase present in Mycobacterium tuberculosis represents an attractive target for anti-tubercular drug discovery. Here we report, the development of a novel series of MTB DNA gyraseB inhibitor identified through a medium throughput screening (MTS) of BITS in-house chemical library (3000 compounds). The MTS hit was further remodeled by chemical synthesis to identify the most potent analogue 27 exhibiting an in vitro gyrB inhibitory IC50 of 0.
View Article and Find Full Text PDFNew anti-tubercular agents, imidazo[1,2-a]pyridine-2-carboxamide derivatives (5a-q) have been designed and synthesized. The structural considerations of the designed molecules were further supported by the docking study with a long-chain enoyl-acyl carrier protein reductase (InhA). The chemical structures of the new compounds were characterized by IR, (1)H NMR, (13)C NMR, HRMS and elemental analysis.
View Article and Find Full Text PDFA series of twenty eight molecules of ethyl 5-(piperazin-1-yl)benzofuran-2-carboxylate and 3-(piperazin-1-yl)benzo[d]isothiazole were designed by molecular hybridization of thiazole aminopiperidine core and carbamide side chain in eight steps and were screened for their in vitro Mycobacterium smegmatis (MS) GyrB ATPase assay, Mycobacterium tuberculosis (MTB) DNA gyrase super coiling assay, antitubercular activity, cytotoxicity and protein-inhibitor interaction assay through differential scanning fluorimetry. Also the orientation and the ligand-protein interactions of the top hit molecules with MS DNA gyrase B subunit active site were investigated applying extra precision mode (XP) of Glide. Among the compounds studied, 4-(benzo[d]isothiazol-3-yl)-N-(4-chlorophenyl)piperazine-1-carboxamide (26) was found to be the most promising inhibitor with an MS GyrB IC50 of 1.
View Article and Find Full Text PDFA series of twenty seven substituted 2-(2-oxobenzo[d]oxazol-3(2H)-yl)acetamide derivatives were designed based on our earlier reported Mycobacterium tuberculosis (MTB) enoyl-acyl carrier protein reductase (InhA) lead. Compounds were evaluated for MTB InhA inhibition study, in vitro activity against drug-sensitive and -resistant MTB strains, and cytotoxicity against RAW 264.7 cell line.
View Article and Find Full Text PDFInhA, the enoyl acyl carrier protein reductase of Mycobacterium tuberculosis (MTB) is an attractive target for developing novel anti-tubercular agents. Twenty eight 2-(4-oxoquinazolin-3(4H)-yl)acetamide derivatives were synthesized and evaluated for their in vitro MTB InhA inhibition. Compounds were further evaluated for their in vitro activity against drug sensitive and resistant MTB strains and cytotoxicity against RAW 264.
View Article and Find Full Text PDFThe pantothenate biosynthetic pathway is essential for the persistent growth and virulence of Mycobacterium tuberculosis (Mtb) and one of the enzymes in the pathway, pantothenate synthetase (PS, EC: 6.3.2.
View Article and Find Full Text PDFDNA gyrase of Mycobacterium tuberculosis (MTB) is a type II topoisomerase and is a well-established and validated target for the development of novel therapeutics. By adapting the medium throughput screening approach, we present the discovery and optimization of ethyl 5-(piperazin-1-yl) benzofuran-2-carboxylate series of mycobacterial DNA gyraseB inhibitors, selected from Birla Institute of Technology and Science (BITS) database chemical library of about 3000 molecules. These compounds were tested for their biological activity; the compound 22 emerged as the most active potent lead with an IC50 of 3.
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