scholarly journals Synthesis and Antimicrobial Activity of Newer Quinazolinones

2006 ◽  
Vol 3 (2) ◽  
pp. 97-102 ◽  
Author(s):  
J. A. Patel ◽  
B. D. Mistry ◽  
K. R. Desai
Keyword(s):  
Antimicrobial Activity ◽  
Diazonium Salts ◽  
Alkyl Aryl

2–alkyl–6–bromo–3,1–benzoxazine–4–one (2) is synthesized by treatingp–Bromoanthranilic acid and Acetylechoride or Benzoylchloride. Reaction of 2–alkyl–6–bromo–3,1–benzoxazine–4–one (2). with hydrazinehydrate furnish the corresponding 3–Amino–2–methyl–6–bromoquinazoline–4(3H)–one (3) which on reaction with benzaldehyde affordN,N– arylidene derivative (4). Reaction of 4 with various diazonium salts yields 6–bromo–2–alkyl/aryl–3{[phenyl(phenyldiazenyl)methylene]amino}quinazolin–4(3H)–one .

scholarly journals Green ultrasound-assisted three-component click synthesis of novel 1H-1,2,3-triazole carrying benzothiazoles and fluorinated-1,2,4-triazole conjugates and their antimicrobial evaluation

2017 ◽  
Vol 67 (3) ◽  
pp. 309-324 ◽  
Author(s):  
Nadjet Rezki ◽  
Mohamed Reda Aouad
Keyword(s):  
Antimicrobial Activity ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Terminal Alkynes ◽  
One Pot ◽  
Alkyl Aryl ◽  
Antimicrobial Evaluation ◽  
Ultrasound Assisted ◽  
Click Synthesis

AbstractThe present study describes an efficient and ecofriendly, ultrasound, one-pot click cycloaddition approach for the construction of a novel series of 1,4-disubstituted-1,2,3-triazoles tethered with fluorinated 1,2,4-triazole-benzothiazole molecular conjugates. It involved three-component condensation of the appropriate bromoacetamide benzothiazole, sodium azide and 4-alkyl/aryl-5-(2-fluorophenyl)-3-(prop-2-ynylthio)-1,2,4-triazoles4a-ethrough a Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction. This approach involvesin situgeneration of azidoacetamide benzothiazole, followed by condensation with terminal alkynes in the presence of CuSO4/Na-ascorbate in aqueous DMSO under both conventional and ultrasound conditions. Some of the designed 1,2,3-triazole conjugates6a-owere recognized for their antimicrobial activity against some bacterial and fungal pathogenic strains.

scholarly journals Unprecedented C-2 arylation of indole with diazonium salts: Syntheses of 2,3-disubstituted indoles and their antimicrobial activity

2011 ◽  
Vol 21 (16) ◽  
pp. 4720-4723 ◽  
Author(s):  
Seth Daly ◽  
Kathryn Hayden ◽  
Indranil Malik ◽  
Nikki Porch ◽  
Hong Tang ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Diazonium Salts

scholarly journals Ketolide Antimicrobial Activity Persists after Disruption of Interactions with Domain II of 23S rRNA

2004 ◽  
Vol 48 (10) ◽  
pp. 3677-3683 ◽  
Author(s):  
Guy W. Novotny ◽  
Lene Jakobsen ◽  
Niels M. Andersen ◽  
Jacob Poehlsgaard ◽  
Stephen Douthwaite
Keyword(s):  
Antimicrobial Activity ◽  
Ribosomal Subunit ◽  
23S Rrna ◽  
Alkyl Aryl ◽  
Interaction Sites ◽  
Enhanced Resistance ◽  
Low Levels ◽  
Domain V ◽  
Block Protein Synthesis ◽  
Do So

ABSTRACT Ketolides are the latest derivatives developed from the macrolide erythromycin to improve antimicrobial activity. All macrolides and ketolides bind to the 50S ribosomal subunit, where they come into contact with adenosine 2058 (A2058) within domain V of the 23S rRNA and block protein synthesis. An additional interaction at nucleotide A752 in the rRNA domain II is made via the synthetic carbamate-alkyl-aryl substituent in the ketolides HMR3647 (telithromycin) and HMR3004, and this interaction contributes to their improved activities. Only a few macrolides, including tylosin, come into contact with domain II of the rRNA and do so via interactions with nucleotides G748 and A752. We have disrupted these macrolide-ketolide interaction sites in the rRNA to assess their relative importance for binding. Base substitutions at A752 were shown to confer low levels of resistance to telithromycin but not to HMR3004, while deletion of A752 confers low levels of resistance to both ketolides. Mutations at position 748 confer no resistance. Substitution of guanine at A2058 gives rise to the MLSB (macrolide, lincosamide, and streptogramin B) phenotype, which confers resistance to all the drugs. However, resistance to ketolides was abolished when the mutation at position 2058 was combined with a mutation in domain II of the same rRNA. In contrast, the same dual mutations in rRNAs conferred enhanced resistance to tylosin. Our results show that the domain II interactions of telithromycin and HMR3004 differ from each other and from those of tylosin. The data provide no indication that mutations within domain II, either alone or in combination with an A2058 mutation, can confer significant levels of telithromycin resistance.

scholarly journals Novel Alkyl(aryl)-Substituted 2,2-Difluoro-6-(trichloromethyl)-2H-1,3,2-oxazaborinin-3-ium-2-uides: Synthesis, Antimicrobial Activity, and CT-DNA Binding Evaluations

2020 ◽  
Vol 11 ◽  
Author(s):  
Wilian C. Rosa ◽  
Inaiá O. Rocha ◽  
Melissa B. Rodrigues ◽  
Helena S. Coelho ◽  
Laura B. Denardi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Dna Binding ◽  
Alkyl Aryl ◽  
Ct Dna

scholarly journals Design, Synthesis, and Antimicrobial Evaluation of Novel Pyrazoles and Pyrazolyl 1,3,4-Thiadiazine Derivatives

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2092 ◽  
Author(s):  
Ibrahim Radini
Keyword(s):  
Antimicrobial Activity ◽  
Minimum Inhibitory Concentration ◽  
Elemental Analysis ◽  
Inhibitory Concentration ◽  
Diazonium Salts ◽  
Design Synthesis ◽  
Antifungal Activities ◽  
Antibacterial And Antifungal Activities ◽  
Antimicrobial Evaluation ◽  
Antibacterial And Antifungal

A novel series of pyrazolyl 1,3,4-thiadiazines 5a–c, 8a–c, 12, 15a–c, 17a–c, and 20 was prepared from the reaction of pyrazole-1-carbothiohydrazide 1a,b with 2-oxo-N′-arylpropanehydrazonoyl chloride, 2-chloro-2-(2-arylhydrazono)acetate, and 3-bromoacetylcoumarin. Moreover, the regioselective reaction of 5-pyrazolone-1-carbothiohydrazide 1a with 4-substituted diazonium salts and 4-(dimethylamino)benzaldehyde gave the corresponding hydrazones 21a–c and 22. The newly prepared compounds were characterized by spectroscopy and elemental analysis. Many new synthesized compounds showed considerable antimicrobial activity against tested microorganisms. Hydrazones 21a–c and 22 showed remarkable antibacterial and antifungal activities. 4-(2-(p-tolyl)hydrazineylidene)-pyrazole-1-carbothiohydrazide 21a displayed the highest antibacterial and antifungal activities with minimum inhibitory concentration (MIC) values lower than standard drugs chloramphenicol and clotrimazole, in the range of 62.5–125 and 2.9–7.8 µg/mL, respectively.

Green synthesis of furo-1,3-oxazole derivatives using Fe3O4-MNPs as efficient nanocatalyst: Study of antimicrobial activity

2020 ◽  
Vol 23 ◽  
Author(s):  
Maryam Ghazvini ◽  
Fatemeh Sheikholeslami-Farahani ◽  
Ashraf Shahvelayati ◽  
Zohreh Rostami ◽  
Saeid Abad
Keyword(s):  
Antimicrobial Activity ◽  
Aqueous Media ◽  
Water Extract ◽  
Sodium Hydride ◽  
Orange Peel ◽  
Catalytic Amount ◽  
Zno Nps ◽  
Alkyl Aryl ◽  
Fe3o4 Mnps ◽  
Oxazole Derivatives

Aim and Objectiv: In this work 1,3-oxazoles were generated using multicomponent reaction of α-bromo ketones, alkyl (aryl) isothiocyanates, sodium hydride and catalytic amount of Fe3O4 MNPs in aqueous media at ambient temperature in good yields. Also, Fe3O4-MNPs were generated using Orange peel water extract as green procedure that reduce the ferric chloride solution. The nanoparticles that is generated via biosynthesis method have potentially valuable in different purposes such as organic synthesis. Also, the antimicrobial activity of some synthesized compounds was studied. Materials and Methods: All of starting materials and solvents for these reactions and preparation of Fe3O4-MNPs and were used with any further purification. The isothiocyanate and -bromo ketones was mixed together in water. After one minutes sodium hydride and Fe3O4 MNPs was added to previouse mixture at room temperature. Then -bromo ketones were added to previous mixture. After completion of the reaction and removal of Fe3O4 MNPs the solid was extracted by filtration and purified by column chromatography. Results: Without employing catalyst, these reactions have low yield and busy mixture. The synthesis of compound 4a as sample reaction have alike yield in the presence of ZnO-NPs and Fe3O4 MNPs (entry 20 and entry 30) but removal of catalyst from the mixture of reaction after completing of reaction is comfortable in present of Fe3O4 MNPs. Structures of 4a–4i are confirmed by IR, 1H NMR, 13C NMR mass spectra. Conclusion: In conclusion, the reaction of α-bromo ketones, isothiocyanate and sodium hydride in the presence of catalytic amount of Fe3O4 MNPs in water generate 1,3-oxazole derivatives in good yields. Some advantages of performing these reactions with present procedure are carrying out these reactions in water as green solvent and simple removal of catalyst.

scholarly journals Synthesis, Characterization, Anti-Inflammatory and in Vitro Antimicrobial Activity of Some Novel Alkyl/Aryl Substituted Tertiary Alcohols

Molecules ◽  
2011 ◽  
Vol 16 (12) ◽  
pp. 10337-10346 ◽  
Author(s):  
Muhammad Baseer ◽  
Farzana Latif Ansari ◽  
Zaman Ashraf ◽  
Rafiuzzaman SaeedulHaq
Keyword(s):  
Antimicrobial Activity ◽  
Alkyl Aryl ◽  
In Vitro Antimicrobial Activity ◽  
Tertiary Alcohols ◽  
Anti Inflammatory

scholarly journals Distinct Mode of Interaction of a Novel Ketolide Antibiotic That Displays Enhanced Antimicrobial Activity

2009 ◽  
Vol 53 (4) ◽  
pp. 1411-1419 ◽  
Author(s):  
Ekaterini C. Kouvela ◽  
Dimitrios L. Kalpaxis ◽  
Daniel N. Wilson ◽  
George P. Dinos
Keyword(s):  
Antimicrobial Activity ◽  
Attachment Site ◽  
23S Rrna ◽  
Side Chain ◽  
Macrolide Antibiotics ◽  
Distinct Mode ◽  
Alkyl Aryl ◽  
Resistant Strains ◽  
Exit Tunnel ◽  
A Site

ABSTRACT Ketolides represent the latest generation of macrolide antibiotics, displaying improved activities against some erythromycin-resistant strains, while maintaining their activity against erythromycin-susceptible ones. In this study, we present a new ketolide, K-1325, that carries an alkyl-aryl side chain at C-13 of the lactone ring. According to our genetic and biochemical studies, K-1325 binds within the nascent polypeptide exit tunnel, at a site previously described as the primary attachment site of all macrolide antibiotics. Compared with telithromycin, K-1325 displays enhanced antimicrobial activity against wild-type Escherichia coli strains, as well as against strains bearing the U2609C mutation in 23S rRNA. Chemical protection experiments showed that the alkyl-aryl side chain of K-1325 interacts specifically with helix 35 of 23S rRNA, a fact leading to an increased affinity of U2609C mutant ribosomes for the drug and rationalizing the enhanced effectiveness of this new ketolide.

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