scholarly journals Synthesis and Biological Evaluation of Some Novel Mannich Bases of Isoxazoline Derivatives as Possible Antimicrobial Agents

2019 ◽  
Vol 31 (12) ◽  
pp. 2821-2826 ◽  
Author(s):  
Seema A. Gosavi ◽  
Dattatray H. Nandal ◽  
Sarita S. Pawar
Keyword(s):  
Antimicrobial Agents ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Hydroxylamine Hydrochloride ◽  
Antimycobacterial Activity ◽  
Mannich Bases ◽  
Biological Evaluation ◽  
Diffusion Method ◽  
Gram Positive Bacteria ◽  
Antimicrobial Studies

Novel isoxazoline derivatives were synthesized by condensation of substituted acetophenones with aldehyde in presence of alcoholic NaOH to get intermediate chalcones, which were further treated with hydroxylamine hydrochloride in presence of sodium hydroxide to get isoxazoline derivatives. The latter were refluxed separately with isonicotinic acid hydrazide and sulphanilamide in presence of formaldehyde for 6-10 h to afford corresponding Mannich bases. The structures of synthesized compounds were established on the basis of melting point, TLC, IR, 1H NMR and HRMS. Antimycobacterial activity of compounds (3a-j) were assessed against M. tuberculosis (vaccine strain, H37 Rv strain) ATCC27294 using microplate Alamar Blue assay (MABA). Further the derivatives were evaluated for the antibacterial activity against Gram positive bacteria S. aureus (ATCC 9144), S. epidemidis (ATCC12228) and Gram negative bacteria E. coli (ATCC 25922), Klebsiella (ATCC 4352), while antifungal activity against A. flavus (ATCC 9643) and A. niger (ATCC 16404) by using agar well diffusion method using ciprofloxacin and fluconazole as standards, respectively. The results of antimicrobial studies showed that some of the derivatives posses mild to moderate biological activity as compared to standard.

scholarly journals Synthesis and Antimicrobial Studies of Some 4-(Substituted)-Ethanoylamino-3-Mercapto-5- (4-Substituted) Phenyl-1,2,4-Triazoles

2012 ◽  
Vol 11 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Neeraj Upmanyu ◽  
Sanjay Kumar ◽  
Kamal Shah ◽  
Pradeep Mishra
Keyword(s):  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Mass Spectral ◽  
Gram Positive Bacteria ◽  
Chemical Structures ◽  
Antibacterial And Antifungal Activities ◽  
Antimicrobial Studies ◽  
Diverse Application ◽  
Substituted Benzoic Acids ◽  
Antibacterial And Antifungal

Triazoles and triazoles with different substituent groups are found to possess diverse application in the  field of medicine and industry. A series of 4-(substituted) ethanoylamino-3-mercapto-5-(4-substituted) phenyl-1,2,4-  triazoles were synthesized as novel antimicrobial agents starting from different 4-substituted benzoic acids. The  chemical structures of these newly synthesized compounds were elucidated by IR, 1H NMR, 13C NMR, FAB+-mass  spectral data and elemental analyses. The antimicrobial activity of title compounds were examined against two gram  positive bacteria (Staphylococcus aureus, Bacillus subtilis), two gram negative bacteria (Escherichia coli,  Pseudomonas aeruginosa) and three fungi (Candida albicans, Aspergillus niger and Fusarium oxysporum) using disc  diffusion method. Some of the compounds bearing methoxy group exhibited moderate to good antibacterial and  antifungal activities. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12481 Dhaka Univ. J. Pharm. Sci. 11(1): 7-18, 2012 (June)

Hybrid Design of Isonicotinic Acid Hydrazide Derivatives: Machine Learning Studies, Synthesis and Biological Evaluation of their Antituberculosis Activity

2020 ◽  
Vol 17 (3) ◽  
pp. 365-375
Author(s):  
Vasyl Kovalishyn ◽  
Diana Hodyna ◽  
Vitaliy O. Sinenko ◽  
Volodymyr Blagodatny ◽  
Ivan Semenyuta ◽  
...  
Keyword(s):  
Machine Learning ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Predictive Ability ◽  
Antitubercular Activity ◽  
Biological Evaluation ◽  
Starting Point ◽  
Binary Classifiers ◽  
Synthesis And Biological Evaluation

Background: Tuberculosis (TB) is an infection disease caused by Mycobacterium tuberculosis (Mtb) bacteria. One of the main causes of mortality from TB is the problem of Mtb resistance to known drugs. Objective: The goal of this work is to identify potent small molecule anti-TB agents by machine learning, synthesis and biological evaluation. Methods: The On-line Chemical Database and Modeling Environment (OCHEM) was used to build predictive machine learning models. Seven compounds were synthesized and tested in vitro for their antitubercular activity against H37Rv and resistant Mtb strains. Results: A set of predictive models was built with OCHEM based on a set of previously synthesized isoniazid (INH) derivatives containing a thiazole core and tested against Mtb. The predictive ability of the models was tested by a 5-fold cross-validation, and resulted in balanced accuracies (BA) of 61–78% for the binary classifiers. Test set validation showed that the models could be instrumental in predicting anti- TB activity with a reasonable accuracy (with BA = 67–79 %) within the applicability domain. Seven designed compounds were synthesized and demonstrated activity against both the H37Rv and multidrugresistant (MDR) Mtb strains resistant to rifampicin and isoniazid. According to the acute toxicity evaluation in Daphnia magna neonates, six compounds were classified as moderately toxic (LD50 in the range of 10−100 mg/L) and one as practically harmless (LD50 in the range of 100−1000 mg/L). Conclusion: The newly identified compounds may represent a starting point for further development of therapies against Mtb. The developed models are available online at OCHEM http://ochem.eu/article/11 1066 and can be used to virtually screen for potential compounds with anti-TB activity.

Evaluation of antibacterial, teratogenicity and antibiofilm effect of sulfated chitosans extracted from marine waste against microorganism

2021 ◽  
pp. 088391152110142
Author(s):  
Velu Gomathy ◽  
Venkatesan Manigandan ◽  
Narasimman Vignesh ◽  
Aavula Thabitha ◽  
Ramachandran Saravanan
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Marine Litter ◽  
Ionization Time ◽  
Gram Positive Bacteria ◽  
Mineral Components ◽  
Ft Ir

Biofilms play a key role in infectious diseases, as they may form on the surface and persist after treatment with various antimicrobial agents. The Staphylococcus aureus, Klebsiella pneumoniae, S. typhimurium, P. aeruginosa, and Escherichia coli most frequently associated with medical devices. Chitosan sulphate from marine litter (SCH-MW) was extracted and the mineral components were determined using atomic absorption spectroscopy (AAS). The degree of deacetylation (DA) of SCH was predicted 50% and 33.3% in crab and shrimp waste respectively. The elucidation of the structure of the SCH-MW was portrayed using FT-IR and 1H-NMR spectroscopy. The molecular mass of SCH-MW was determined with Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). The teratogenicity of SCH-MW was characterized by the zebrafish embryo (ZFE) model. Antimicrobial activity of SCH-MW was tested with the agar well diffusion method; the inhibitory effect of SCH-MW on biofilm formation was assessed in 96 flat well polystyrene plates. The result revealed that a low concentration of crab-sulfated chitosan inhibited bacterial growth and significantly reduced the anti-biofilm activity of gram-negative and gram-positive bacteria relatively to shrimp. It is potentially against the biofilm formation of pathogenic bacteria.

scholarly journals Isoniazid induces expression of the antigen 85 complex in Mycobacterium tuberculosis.

1996 ◽  
Vol 40 (7) ◽  
pp. 1754-1756 ◽  
Author(s):  
T R Garbe ◽  
N S Hibler ◽  
V Deretic
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antimicrobial Agents ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Isonicotinic Acid Hydrazide ◽  
Two Dimensional Gel Electrophoresis ◽  
Mycolic Acids ◽  
Mycobacterium Tuberculosis H37rv ◽  
Antigen 85 ◽  
Differential Gene

Exposure to isoniazid induced the expression of several secreted proteins in Mycobacterium tuberculosis H37Rv. Two-dimensional gel electrophoresis and immunoblot analyses indicated that two of the prominent isonicotinic acid hydrazide-inducible polypeptides were members of the antigen 85 complex, recently demonstrated to have mycolyltransferase activity. We postulate the existence of an intermediate, whose production is inhibited by isonicotinic acid hydrazide, which plays a negative feedback regulatory role in the metabolism of mycolic acids are revealed by the overexpression of the antigen 85 complex. The approach described here relies on analyses of differential gene expression following exposure to inhibitors and may become a more general tool in dissecting the effects of antimicrobial agents.

scholarly journals Novel Nonsymmetrically p-Benzyl-Substituted (Benz)imidazole N-Heterocyclic Carbene-Silver(I) Acetate Complexes: Synthesis and Biological Evaluation

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Frauke Hackenberg ◽  
Anthony Deally ◽  
Grainne Lally ◽  
Sina Malenke ◽  
Helge Müller-Bunz ◽  
...  
Keyword(s):  
Cancer Cell Line ◽  
Benzyl Bromide ◽  
Biological Evaluation ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Gram Positive Bacteria ◽  
Acetate Complex ◽  
Renal Cancer Cell ◽  
Synthesis And Biological Evaluation

Nonsymmetrically substituted N-heterocyclic carbene (NHC) precursors 1a–d and 3a–d were synthesised by first reacting 1H-(benz)imidazole with p-cyanobenzyl bromide to give 4-(1H-imidazole-1-ylmethyl)benzonitrile (1) and 4-(1H-benzimidazole-1-ylmethyl)benzonitrile (3) and afterwards introducing benzyl bromide, 1-(bromomethyl)-4-methylbenzene, 1-(bromomethyl)-4-methoxybenzene, and methyl 4-(bromomethyl)benzoate. The NHC-silver(I) acetate complexes (1-benzyl-3-(4-cyanobenzyl)-2,3-dihydro-1H-imidazole-2-ylidene) silver(I) acetate (2a), (1-(4-cyanobenzyl)-3-(4-methylbenzyl)-2,3-dihydro-1H-imidazole-2-ylidene) silver(I) acetate (2b), (1-(4-cyanobenzyl)-3-[4-(methoxycarbonyl)benzyl]-2,3-dihydro-1H-imidazole-2-ylidene) silver(I) acetate (2c), (1-benzyl-3-(4-cyanobenzyl)-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4a), (1-(4-cyanobenzyl)-3-(4-methylbenzyl)-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4b), (1-(4-cyanobenzyl)-3-(4-methoxybenzyl)-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4c), and (1-(4-cyanobenzyl)-3-[4-(methoxycarbonyl)benzyl]-2,3-dihydro-1H-benzimidazole-2-ylidene) silver(I) acetate (4d) were yielded by reacting these NHC precursors with silver(I) acetate. The silver(I) acetate complex 4b was characterised by single crystal X-ray diffraction. Preliminary in vitro antibacterial studies against the Gram-positive bacteria Staphylococcus aureus and the Gram-negative bacteria Escherichia coli, using the Kirby-Bauer disc diffusion method, were carried out on the seven NHC-silver(I) acetate complexes 2a–c and 4a–d. Also the IC50 values of these seven complexes were determined by an MTT-based assay against the human renal cancer cell line Caki-1. The complexes 2a–c and 4a–c revealed the following IC50 values, respectively, 25 (±1), 15 (±2), 5.4 (±0.8), 16 (±2), 7.1 (±1), 20 (±4), and 14 (±1) μM.

scholarly journals Nitric Oxide Generated from Isoniazid Activation by KatG: Source of Nitric Oxide and Activity against Mycobacterium tuberculosis

2004 ◽  
Vol 48 (8) ◽  
pp. 3006-3009 ◽  
Author(s):  
Graham S. Timmins ◽  
Sharon Master ◽  
Frank Rusnak ◽  
Vojo Deretic
Keyword(s):  
Nitric Oxide ◽  
Mycobacterium Tuberculosis ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Antimycobacterial Activity ◽  
Paramagnetic Resonance ◽  
Catalase Peroxidase ◽  
Resonance Spin ◽  
Electron Paramagnetic ◽  
Mycobacterial Protein

ABSTRACT Isonicotinic acid hydrazide (INH) is a frontline antituberculosis agent. Once taken up by Mycobacterium tuberculosis, INH requires activation by the catalase-peroxidase KatG, converting INH from its prodrug form into a range of bactericidal reactive species. Here we used 15N-labeled INH together with electron paramagnetic resonance spin trapping techniques to demonstrate that nitric oxide (NO˙) is generated from oxidation at the hydrazide nitrogens during the activation of INH by M. tuberculosis KatG. We also observed that a specific scavenger of NO˙ provided protection against the antimycobacterial activity of INH in bacterial culture. No significant increases in mycobacterial protein nitration were detected, suggesting that NO˙ and not peroxynitrite, a nitrating metabolite of NO·, is involved in antimycobacterial action. In conclusion, INH-derived NO· has biological activity, which directly contributes to the antimycobacterial action of INH.

scholarly journals ELEMENTAL AND MEDICINAL EVALUATION OF THE LEAF EXTRACT OF PILOSTIGMA RETICULATUM (DC) HOCHST

2019 ◽  
Vol 7 (7) ◽  
pp. 391-397
Author(s):  
O. Adeyanju ◽  
S. V. Francis ◽  
R. R. Ede ◽  
P.S. Jang ◽  
J.K. Bulus
Keyword(s):  
Elemental Analysis ◽  
Leaf Extract ◽  
Antimicrobial Agents ◽  
Ethanolic Extract ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Plant Sample ◽  
Antimicrobial Studies ◽  
Phytochemical Investigation

Elemental analysis, phytochemical screening and antimicrobial activities of aqueous and ethanolic leaf extract of Pilostigma reticulatum (dc) Hochst were studied using paper disc diffusion method against Streptococcus pyogen, Escherichia coli and Salmonella thvpi. Elemental analysis of the plant sample revealed the presence of Ca (1.51 ± 0.01μg/g), Mg (0.43 ± 0.02μg/g). P (0.29 ± 0.01 μg/g), Mn (3.01 ± 0.01 μg/g), Fe (1.04 ± 0.01 μg/g), Zn (1.05 ± 0.02  and Cu was below detectable limit(BDL).The results of the antimicrobial studies indicated that the extracts inhibited the growth of one or more tested pathogens.The ethanolic extract showed a broad spectrum of antimicrobial activity. Phytochemical investigation revealed the presence of tannins, alkaloids, glycosides, flavonoids, carbohydrates and terpenes. Anthraquinone and saponin were not present. Inhibition zone by the extract ranges from 4.0mm to 30mm.The minimum inhibitory concentration (MIC) ranges from 8.0 x102 µg/ml to 1x104 µg/ml. Pilostigma reticulatum leaf may be able to produce antimicrobial agents in drug delivery.

scholarly journals Efficient Synthesis, Spectral, Characterization, Antimicrobial and DFT Studies of Antimony(III) Dithiocarbamates

2021 ◽  
Vol 34 (1) ◽  
pp. 42-52
Author(s):  
S. Tamilvanan
Keyword(s):  
Density Functional ◽  
Theoretical Calculations ◽  
Mulliken Charge ◽  
Diffusion Method ◽  
Hydrogen Atoms ◽  
Gram Positive Bacteria ◽  
Antimicrobial Studies ◽  
Fungal Organisms ◽  
Ft Ir

The synthesis and characterization of novel antimony(III) dithiocarbamate complexes tris(N-furfuryl- N-propyldithiocarbamato-S,S′)antimony(III) (1) and tris(N-furfuryl-N-butyldithiocarbamato- S,S′)antimony(III) (2) have been characterized by elemental analysis, FT-IR, NMR (1H and 13C) spectra and antimicrobial studies. The characteristic thioureide (νC-N) bands occur at 1462 and 1475 cm-1 for complex 1 and 2, respectively. The theoretical calculations of the complexes have been carried out by density functional theory (DFT). The FMOs, MEP, Mulliken charge distribution and chemical activity parameters of the optimized structure have been calculated at the same level of theory. The MEP structure indicated that the positive and negative potential sites are around hydrogen atoms and electronegative atoms of the studied complexes, respectively. The Agar-well diffusion method were used to study the antimicrobial activity of the complexes against two Gram-positive bacteria (Klebsiella pneumoniae and Staphylococcus aureus), two Gram-negative bacteria (Escherichia coli and Vibrio cholera) and two fungal organisms (Candida albicans and Aspergillus niger).

Highly Regioselective Ring-Opening of Epoxides: Synthesis and Biological Evaluation as Potent Antimicrobial Agents

2021 ◽  
Vol 6 (3) ◽  
pp. 228-234
Author(s):  
Nilam H. Lalavani ◽  
Krishna A. Bhensdadia ◽  
Shipra H. Baluja
Keyword(s):  
Ring Opening ◽  
Antimicrobial Agents ◽  
Catalytic Amount ◽  
Biological Evaluation ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Mass Spectral ◽  
Fungal Strains ◽  
Ring Opening Of Epoxides

In present work, a convenient method for the nucleophilic ring-opening of epoxides with secondary amine in presence of ethyl acetate as a polar aprotic solvent using catalytic amount of base is described. Present method is highly regioselective and furnishes the products in short time of period with excellent yield. The regioselectivity of this ring opening was confirmed using FT-IR, 1H NMR, 13C NMR, elemental analysis and mass spectral data. The antimicrobial screening of all these synthesized compounds was done against some bacterial and fungal strains in two polar solvents, DMSO and DMF using agar well diffusion method. These compounds showed good inhibition of bacterial strains and potent against fungal strains than standard drug.

scholarly journals PARTIAL CHARACTERIZATION AND ANTIMICROBIAL PROPERTY OF SMALL PEPTIDES ISOLATED FROM THE FLOWERS OF MILLINGTONIA HORTENSIS

2018 ◽  
Vol 11 (12) ◽  
pp. 354
Author(s):  
Angayarkanni R ◽  
Sridevi G
Keyword(s):  
Antimicrobial Property ◽  
Antimicrobial Properties ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Chromatographic Technique ◽  
Small Peptides ◽  
Purification And Characterization ◽  
Gram Positive Bacteria ◽  
Antimicrobial Studies

Objective: The flowers of Millingtonia hortensis were initially screened for the presence of Cu (II) ninhydrin-positive compounds. Purification and characterization of small alpha peptides from the flowers of M. hortensis have been done. Further elucidation of the antimicrobial properties of these small peptides is also taken as part of the work.Methods: Using 80% aqueous ethanol the crude extract was prepared and screening was carried out by a circular paper chromatographic technique. Purification and characterization of small alpha peptides from the flowers of M. hortensis have been done. Further elucidation of the antimicrobial properties of these small peptides by disc diffusion method is also taken as part of the work.Results: Based on the findings of UV–visible spectrophotometer, it is confirmed that the purified compound is a small peptide and might contain glycine, cysteine, and tyrosine or histidine. The result of antimicrobial studies proves the ability of small peptides to function as antimicrobial peptides.Conclusion: It is concluded that the small peptides show an inhibitory effect against various Gram-negative and some Gram-positive bacteria.

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