scholarly journals Synthesis and Evaluation of Some Novel Chromone Based Dithiazoles as Antimicrobial Agents

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Naureen Aggarwal ◽  
Vishal Sharma ◽  
Harpreet Kaur ◽  
Mohan Paul Singh Ishar

Novel substituted 1,2,4-dithiazolylchromones 3a–j were synthesized by the reaction of 3-formylchromones (1a–j) with two equivalents of p-chlorothiobenzamide (2) in dry xylene and characterized spectroscopically (IR, 1H and 13C NMR, mass) and elemental analysis. All synthesized compounds were screened for in vitro antimicrobial activity against various pathogenic bacterial and fungal strains and were found to possess good to moderate inhibitory potential against all tested strains. Antimicrobial results reveal that compounds bearing lipophilic electron withdrawing groups such as chloro and bromo displayed significant inhibitory potential against both bacterial and fungal strains. Particularly, compound 3c displayed significant inhibitory against bacterial strains and compound 3h exhibits significant inhibitory potential in comparison to standard drug fluconazole against fungal strain S. cerevisiae.

Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.


Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Ibrahim Al- Adham ◽  
Najah Al-muhtaseb

<p><strong>Objective: </strong>To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.</p><p><strong>Methods: </strong>A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, <sup>1</sup>H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d<sub>6</sub> as a solvent.<em> </em><em>In vitro </em>antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. <em></em></p><p><strong>Results: </strong>The IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against <em>Pseudomonas aeruginosa </em>(<em>P. aeruginosa</em>), AZ-9 demonstrated the highest antifungal activity against <em>Candida albicans </em>(<em>C. albicans</em>), with MIC of 31.25 µg/ml.</p><p><strong>Conclusion: </strong>These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.</p>


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7119
Author(s):  
Huda R. M. Rashdan ◽  
Aboubakr H. Abdelmonsef ◽  
Mortaga M. Abou-Krisha ◽  
Tarek A. Yousef

2-azido-1H-benzo[d]imidazole derivatives 1a,b were reacted with a β-ketoester such as acetylacetone in the presence of sodium ethoxide to obtain the desired molecules 2a,b. The latter acted as a key molecule for the synthesis of new carbazone derivatives 4a,b that were submitted to react with 2-oxo-N-phenyl-2-(phenylamino)acetohydrazonoyl chloride to obtain the target thiadiazole derivatives 6a,b. The structures of the newly synthesized compounds were inferred from correct spectral and microanalytical data. Moreover, the newly prepared compounds were subjected to molecular docking studies with DNA gyrase B and exhibited binding energy that extended from −9.8 to −6.4 kcal/mol, which confirmed their excellent potency. The compounds 6a,b were found to be with the minimum binding energy (−9.7 and −9.8 kcal/mol) as compared to the standard drug ciprofloxacin (−7.4 kcal/mol) against the target enzyme DNA gyrase B. In addition, the newly synthesized compounds were also examined and screened for their in vitro antimicrobial activity against pathogenic microorganisms Staphylococcus aureus, E. coli, Pseudomonas aeruginosa, Aspergillus niger, and Candida albicans. Among the newly synthesized molecules, significant antimicrobial activity against all the tested microorganisms was obtained for the compounds 6a,b. The in silico and in vitro findings showed that compounds 6a,b were the most active against bacterial strains, and could serve as potential antimicrobial agents.


2021 ◽  
Vol 11 (6) ◽  
pp. 888-903
Author(s):  
Hanan Alghamdi ◽  
Syed Nazreen ◽  
Ahmed A. Elhenawy ◽  
Mohamed Abdelbaset

The antimicrobial resistance is a global human threat which has led to the withdrawal of antibiotics from the market. Therefore, it is a need to develop new and effective antimicrobial agents to overcome this problem. In this paper, new Dioxovanadium(V) complexes (1–8) with ligands viz. (2-(5-phenyl-1,3,4-oxadiazole-2-yl)phenol; L1) and 2,5-bis(2-hydroxyphenyl)-1,3,4-oxadiazole (L2) were synthesized and assessed for antimicrobial-activity. Both a bidentate and tetradentate oxadiazole ligands coordinate with vanadium ions through the nitrogen and oxygen atoms giving octahedral geometries. Thermal analysis and IR data confirmed the presence of hydrated water in the metal-complexes. The investigated compounds were assessed for antimicrobial viz four strains of bacterial and one a fungal strain. The antibacterial data showed that, the complexes (1–8) are lower potency against bacterial strain than the free ligands except (5) and (7) complexes. These complexness showed the highest antibacterial potency via the Staphylococcus aureus. All investigated compounds were inactive against C. albicans except complexes 2 and 5 which showed high activity. The performance of DFT was conducted to examine an interaction mode of the target compounds with biological system. The QSPR was calculated as: optimization geometries, (FMOs), and chemical-reactivities for the synthesized compounds. The (MEPs) were figured to predict the interaction behavior of the ligand and its complexes against the receptor. The molecular docking was performed against DNA gyrase to study the interaction mode with biological system.


2012 ◽  
Vol 2 (5) ◽  
pp. 217-226
Author(s):  
E. O. Omwenga ◽  
P. O. Okemo ◽  
P. K. Mbugua

The antimicrobial effect of some selected Samburu medicinal plants was evaluated on bacterial strains like Staphylococcus aureus ‐ ATCC 20591, Bacillus subtillis ‐ Local isolate, Salmonella typhi‐ATCC 2202, Escherichia coli‐STD. 25922 and Pseudomonas aeroginosa ‐ ATCC 25852 and fungal strains like Candida albicans ATCC EK138, Aspergillus niger ATCC 16404, Aspergillusflavus‐Local isolate, Fusarium lateritium‐Local isolate, and Penicillium spp.‐ local isolate. Methanol was used as solvent for the extraction from the selected medicinal plants used by the Samburu community. The in vitro antimicrobial activity was performed by agar disc diffusion and micro‐dilution technique. The most susceptible Gram‐positive bacterium was S. aureus, while the most susceptible Gram‐negative bacterium was P. aeroginosa. The extracts of Gomphocarpus fruticosus (L) W.T. Aiton showed less activity against the bacterial strains investigated. The most active antibacterial plants were Euphorbia scarlatica S. Carter, and Euclea divinoram Hiern. Incidentally most of the extracts were inactive against the fungal strains with only a few proving to be slightly active against the C. albicans i.e. Loranthus acaciae Zucc., Kedrostis pseudogijef (Gilg) C. Jeffrey, Euclea divinoram Hiern. and Croton macrostachyus (A. Rich). Benths. The significant antimicrobial activity of active extracts was compared with the standard antimicrobials, cefrodoxima, amoxicillin and fluconazole. The MICs of the most active plants ranged from 18.75mg/ml to 37.50mg/ml. The MBCs ranged between 18.75mg/ml to75mg/ml. These results were significant at P< 0.01. The findings show that most of the medicinal plants used by the Samburu community have some significant activity on the bacterial but not fungal pathogens known to cause diarrhoea.


2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Ajai Kumar ◽  
Suriya P. Singh ◽  
Sudarshan S. Chhokar

From the seeds of C arum copticum thymol (1) was isolated as the major component and ten derivatives (2–11) were prepared by reacting it with different acid chlorides in a single step. They were evaluated for antimicrobial activity against twelve bacterial strains and nine fungal strains using disc diffusion and broth dilution assays. Derivative 9 was found to be most active against both bacterial and fungal strains.


2010 ◽  
Vol 75 (6) ◽  
pp. 739-747 ◽  
Author(s):  
Dinesh Bisht ◽  
Rajendra Padalia ◽  
Lalit Singh ◽  
Veena Pande ◽  
Priyanka Lal ◽  
...  

The essential oils from six Himalayan Nepeta species, viz. Nepeta leucophylla Benth., Nepeta discolor Royle ex Benth., Nepeta govaniana Benth., Nepeta clarkei Hook f., Nepeta elliptica Royle ex Benth. and Nepeta erecta Benth., were tested for their in vitro antimicrobial activity against six pathogenic bacterial and two fungal strains. The results showed that Pseudomonas aeruginosa was the most sensitive strain tested to the essential oils of Nepeta species. The essential oils of N. elliptica and N. erecta exhibited the highest activity against P. aeruginosa, followed by the essential oils of N. leucophylla and N. clarkei. The essential oils from N. elliptica and N. erecta were also found to be very effective against Serratia marcescens; while the essential oil from N. leucophylla displayed significant activity against Proteus vulgaris and Staphylococcus aureus. Other bacterial strains displayed variable degree of susceptibility against one or more of the tested essential oils. The essential oil from N. leucophylla also showed the highest antifungal activity against both tested fungal strains, viz. Candida albicans and Trichophyton rubrum, followed by the essential oils from N. clarkei, N. govaniana and N. erecta. Iridodial derivatives, viz. iridodial ?-monoenol acetate (25.4 %), dihydroiridodial diacetate (18.2 %) and iridodial dienol diacetate (7.8 %) were identified as the major constituents of N. leucophylla, while the essential oils from N. elliptica and N. erecta were dominated by (7R)-trans, trans nepetalactone (83.4 %) and isoiridomyrmecin (66.7 %), respectively. The essential oil of N. discolor was characterized by 1,8-cineole (25.5 %) and ?-caryophyllene (18.6 %), while N. clarkei was dominated by ?-sesquiphellandrene (22.0 %) and germacrene D (13.0 %). Isoiridomyrmecin (35.2 %) and pregeijerene (20.7 %) were identified as the major constituents of N. govaniana. In general the Nepeta species containing constituents with an iridoid or lactone skeleton were found to have the greater antagonistic activity against most of the microbial strains as compared to those containing regular terpene constituents.


2021 ◽  
Vol 37 (2) ◽  
pp. 508-512
Author(s):  
Jaganmohana Rao Saketi ◽  
S N Murthy Boddapati ◽  
Raghuram M ◽  
Geetha Bhavani Koduru ◽  
Haribabu Bollikolla

The in vitroantimicrobial properties of a series of N-methyl-3-aryl indazoles (5a-5j) were screened. In this present work, we describe our efforts towards the development of potent antimicrobial activity of synthesized indazole derivatives. The antimicrobial activities of the prepared compounds were investigated against four bacterial strains: Xanthomonas campestris, Escherichia coli, Bacillus cereus, Bacillus megaterium, and a fungal strain Candida albicans. The biological evaluation studies of these indazole derivatives revealed that some of these tested compounds have shown moderate to goodin vitroantimicrobial activities.


2019 ◽  
Vol 70 (6) ◽  
pp. 1996-1999
Author(s):  
Catalin Araniciu ◽  
Smaranda Dafina Oniga ◽  
Cristina Ioana Stoica ◽  
Mariana Carmen Chifiriuc ◽  
Marcela Popa ◽  
...  

Considering the promising antimicrobial activity of compounds bearing the thiazole or the oxadiazole rings in their structures, we set out to obtain new antimicrobial molecules bearing the 2-(thiazol-5-yl)-1,3,4-oxadiazole schaffold. The structures of the 8 new compounds obtained was confirmed by physicochemical characterization including: 1H-NMR, MS and elemental analysis. Antimicrobial activity was investigated against 5 Gram-positive bacterial strains, 2 Gram-negative bacterial strains and 2 fungal strains. The newly synthesized compounds showed modest antimicrobial activity.


2018 ◽  
Vol 16 (2) ◽  
pp. 160-173 ◽  
Author(s):  
Mir Mohammad Masood ◽  
Mohammad Irfan ◽  
Shadab Alam ◽  
Phool Hasan ◽  
Aarfa Queen ◽  
...  

Background: 2,4-disubstituted-1,3-thiazole derivatives (2a–j), (3a–f) and (4a–f) were synthesized, characterized and screened for their potential as antimicrobial agents. In the preliminary screening against a panel of bacterial strains, nine compounds showed moderate to potent antibacterial activity (IC50 = 13.7-90.8 μg/ml). </P><P> Methods: In the antifungal screening, compound (4c) displayed potent antifungal activity (IC50 = 26.5 &#181;g/ml) against Candida tropicalis comparable to the standard drug, fluconazole (IC50 = 10.5 &#181;g/ml). Based on in vitro antimicrobial results, compounds 2f, 4c and 4e were selected for further pharmacological investigations. Hemolytic activity using human red blood cells (hRBCs) and cytotoxicity by MTT assay on human embryonic kidney (HEK-293) cells revealed non-toxic nature of the selected compounds (2f, 4c and 4e). To ascertain their possible mode of action, docking studies with the lead inhibitors (2f, 4c and 4e) were performed using crystal structure coordinates of bacterial methionine aminopeptidases (MetAPs), an enzyme involved in bacterial protein synthesis and maturation. Results: The results of in vitro and in silico studies provide a rationale for selected compounds (2f, 4c and 4e) to be carried forward for further structural modifications and structure-activity relationship (SAR) studies against these bacterial infections. Conclusion: The study suggested binding with one or more key amino acid residues in the active site of Streptococcus pneumoniae MetAP (SpMetAP) and Escherichia coli MetAP (EcMetAP). In silico physicochemical properties using QikProp confirmed their drug likeliness.


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