Synthesis and application of some new S-(substituted)thio- and thienoquinoline derivatives as antimicrobial agents

1991 ◽  
Vol 56 (8) ◽  
pp. 1749-1760 ◽  
Author(s):  
Ibrahim M. A. Awad ◽  
Abdu E. Abdel-Rahman ◽  
Etify A. Bakhite

Ethyl (4-aryl-3-cyano-5,6,7,8-tetrahydro-2-quinolinylthio) acetate (IIa, IIb) were prepared and reacted with hydrazine hydrate to give hydrazines IIIa, IIIb which underwent cyclization into thienoquinoline derivatives IVa, IVb. Reaction of IIIa, IIIb with phenyl isocyanate yielded semicarbazides Va, Vb. Similarly, IIIa, IIIb and IVb were interacted with methyl/phenyl isothiocyanates affording the corresponding thiosemicarbazide derivatives VIa - VId and XIVa, XIVb respectively. On the other hand, condensation of IIIb with acetylacetone gave the pyrazole VII treatment with ethoxide furnished VIII. Also, IIIa, IIIb and IVa, IVb reacted with aromatic aldehydes to afford hydrazones IXa - IXf and XIa - XIf respectively. Cyclodehydration of IXd - IXf with thioglycolic acid furnished 4-thiazolidinone derivatives Xa - Xc. Moreover, IVb was reacted with formic acid/acetic anhydride to give XII and XIII. Diazotization of IVb gave azide XV which underwent Curtius rearrangement into XVI. The structures of all newly synthesized compounds were confirmed by elemental analyses and spectral data. Also, the most of these compounds were tested in vitro for their antimicrobial activities against some Gram-positive and Gram-negative bacteria.

2010 ◽  
Vol 65 (12) ◽  
pp. 1509-1515 ◽  
Author(s):  
Manjunatha Kumsi ◽  
Boja Poojary ◽  
Prajwal Lourdes Lobo ◽  
Nalilu Suchetha Kumari ◽  
Anoop Chullikana

The key precursor rac-2-(4-isobutylphenyl)ethyl-1,2,4-triazole-5-thione (3) was synthesized in good yield from Ibuprofen (1). One-pot three-component reactions of 3 with 5-aryl-furan-2-carboxaldehydes/ substituted aromatic aldehydes and monochloroacetic acid in acetic acid in the presence of acetic anhydride and anhydrous sodium acetate afforded substituted thiazolo[3,2-b][1,2,4]triazole derivatives 4 and 5. The structures of the newly synthesized compounds were elucidated by elemental analyses and spectral data. The compounds were tested for their in-vitro antimicrobial activities.


Author(s):  
Mayuri A. Borad ◽  
Manoj N. Bhoi ◽  
Jagruti A. Parmar ◽  
Hitesh D. Patel

As part of continuing studies in emerging new antibacterial agent, a novel series of N-(benzo[d] thiazol-2-yl)-2-((2,4’-dioxospiro[indoline-3, 2’-thiazolidin]-3'-yl)amino)acetamide derivatives were synthesized by sequencing reaction of 2-aminobenzothiazole with chloroacetyl chloride, hydrazine hydrate, isatin and Thioglycolic acid. The novel heterocycles were characterized by elemental analyses and various spectroscopic techniques. The synthesized compounds were tested in-vitro antibacterial activity against two Gram-positive and two Gram-negative bacteria. Bacteriological results showed that compound 5c possessed a broad spectrum of antibacterial activity against the tested microorganisms.


2020 ◽  
Vol 20 (3) ◽  
pp. 192-208 ◽  
Author(s):  
Talita Odriane Custodio Leite ◽  
Juliana Silva Novais ◽  
Beatriz Lima Cosenza de Carvalho ◽  
Vitor Francisco Ferreira ◽  
Leonardo Alves Miceli ◽  
...  

Background: According to the World Health Organization, antimicrobial resistance is one of the most important public health threats of the 21st century. Therefore, there is an urgent need for the development of antimicrobial agents with new mechanism of action, especially those capable of evading known resistance mechanisms. Objective: We described the synthesis, in vitro antimicrobial evaluation, and in silico analysis of a series of 1H-indole-4,7-dione derivatives. Methods: The new series of 1H-indole-4,7-diones was prepared with good yield by using a copper(II)- mediated reaction between bromoquinone and β-enamino ketones bearing alkyl or phenyl groups attached to the nitrogen atom. The antimicrobial potential of indole derivatives was assessed. Molecular docking studies were also performed using AutoDock 4.2 for Windows. Characterization of all compounds was confirmed by one- and two-dimensional NMR techniques 1H and 13C NMR spectra [1H, 13C – APT, 1H x 1H – COSY, HSQC and HMBC], IR and mass spectrometry analysis. Results: Several indolequinone compounds showed effective antimicrobial profile against Grampositive (MIC = 16 µg.mL-1) and Gram-negative bacteria (MIC = 8 µg.mL-1) similar to antimicrobials current on the market. The 3-acetyl-1-(2,5-dimethylphenyl)-1H-indole-4,7-dione derivative exhibited an important effect against different biofilm stages formed by a serious hospital life-threatening resistant strain of Methicillin-Resistant Staphylococcus aureus (MRSA). A hemocompatibility profile analysis based on in vitro hemolysis assays revealed the low toxicity effects of this new series. Indeed, in silico studies showed a good pharmacokinetics and toxicological profiles for all indolequinone derivatives, reinforcing their feasibility to display a promising oral bioavailability. An elucidation of the promising indolequinone derivatives binding mode was achieved, showing interactions with important sites to biological activity of S. aureus DNA gyrase. These results highlighted 3-acetyl-1-(2-hydroxyethyl)-1Hindole- 4,7-dione derivative as broad-spectrum antimicrobial prototype to be further explored for treating bacterial infections. Conclusion: The highly substituted indolequinones were obtained in moderate to good yields. The pharmacological study indicated that these compounds should be exploited in the search for a leading substance in a project aimed at obtaining new antimicrobials effective against Gram-negative bacteria.


2019 ◽  
Vol 15 (1) ◽  
pp. 63-70
Author(s):  
Shiv Dev Singh ◽  
Arvind Kumar ◽  
Firoz Babar ◽  
Neetu Sachan ◽  
Arun Kumar Sharma

Background: Thienopyrimidines are the bioisoster of quinazoline and unlike quinazoline exist in three isomeric forms corresponding to the three possible types annulation of thiophene to the pyrimidine ring viz thieno[2,3-d] pyrimidine, thieno[3,2-d] pyrimidine and thieno[3,4-d]pyrimidine. Heterocyclic containing the thienopyrimidinone moiety exhibits various pronounced activities such as anti-hypertensive, analgesic and anti-inflammatory, antiviral, platelet aggregation inhibitory, antiprotozoal bronchodilatory, phosphodiesterase inhibitory, antihistaminic, antipsychotic and antimicrobial activity. Objective: Synthesis of novel 3(N,N-dialkylamino)alkyl/phenyl substituted thieno[2,3-d]pyrimidinones as H1-anti-histaminic and antimicrobial agents. Methods: A series of 3-[(N,N-dialkylamino)alkyl/phenyl]-2-(1H)thioxo-5,6,7,8-tetrahydrobenzo(b) thieno(2,3-d)pyrimidine-4(3H)-ones[4a-d], their oxo analogous [5a-d] and 3-[(N,N-dialkylamino)alkyl]- 2-chlorophenyl-5,6,7,8-tetrahydrobenzo(b)thieno(2,3-d)pyrimidine- 4 (3H)-ones[6a-d]derivative were synthesized from 2-amino-4,5,6,7-tetrahydrobenzo(b)thiophene-3-carboxylic acid by nucleophilic substitution of different N,N-dialkyl alkylene/phenylene diamines on activated 3-acylchloride moiety followed by cyclocondensation with carbon disulfide and ethanolic potassium hydroxide to get [4a-d] and in second reaction by condensation with 4-chlorobenzoyl chloride to get [6a-d] by single pot novel innovative route. The oxo analogous [5a-d] were prepared by treating derivatives [4a-d] with potassium permagnate in ethanolic KOH. The synthesized compound were evaluated for H1-antihistaminic and antimicrobial activities. Results: All synthesized compounds exhibited significant H1-antihistaminic activity by in vitro and in vivo screening methods and data were verified analytically and statistically. The compound 4a, 4b, 5a and 5b showed significant H1-antihistaminiic activity than the reference standard chlorpheniramine maleate. The compound 6d, 6c, 5c and 4c exhibited significant antimicrobial activity.


2013 ◽  
Vol 8 (1) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Ismail Kiran ◽  
Özge Özşen ◽  
Turgay Çelik ◽  
Semra İlhan ◽  
Bükay Yenice Gürsu ◽  
...  

Isophorone (3,5,5-trimethyl-2-cyclohexen-1-one), a monoterpene, and the structurally related 1,8-cineole and camphor, have demonstrated a protective effect against cancer, biological activity against a variety of microorganisms, and anti-oxidant properties. The derivatization of isophorone is, therefore, an important field of xenobiochemistry, pharmacology and toxicology. The aim of this study was to obtain derivatives of isophorone through microbial biotransformation and evaluate the biotransformation metabolites as potential antimicrobial agents. Incubation of isophorone with the fungi Alternaria alternata and Neurospora crassa afforded 4α-hydroxy- and 7-hydroxy-isophorone as transformation metabolites. The antimicrobial activities of isophorone and the metabolites were evaluated in vitro both by using agar dilution and microdilution methods. However, no significant antibacterial activity was observed when compared with those of standard substances.


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Vineet Kumar Choudhary ◽  
Abhishek Kumar ◽  
Neeraj Sharma

AbstractThe new diorganotin(IV) complexes of composition [Me2Sn(C6H5OCH2CONHO)2](I) and [n-Bu2Sn(C6H5OCH2CONHO)2](II) have been synthesized by the reactions of Me2SnCl2andn-Bu2SnCl2with potassium phenoxyacetohydroxamate (PhOAHK=C6H5OCH2CONHOK) in 1:2 molar ratio in methanol and benzene solvent medium and characterized by elemental analyses and spectroscopic techniques (infrared,1H nuclear magnetic resonance and mass spectrometry). The [O,O coordination] through carbonyl and hydroxamic oxygen atoms and distorted octahedral geometry around the mononuclear tin has been inferred. The electrochemical behavior of complexes studied by the cyclic voltammetric technique has shown quasi-irreversible two-step reduction from tin (IV) to tin (II). Thermal behavior of complexes studied by the thermogravimetric technique in N2atmosphere has yielded SnO as the decomposition product. Thein vitroantimicrobial activity assays against various pathogenic Gram-negative bacteria, namely,Salmonella typhi,Escherichia coli; Gram-positiveBacillus cereusandStaphylococcus aureusand fungiAspergillus nigerandAlternaria alternataby the minimum inhibitory concentration method have shown their potential as promising antimicrobial agents compared to the respective standard chloramphenicol and nystatin drugs.


2020 ◽  
Vol 75 (10) ◽  
pp. 2907-2913 ◽  
Author(s):  
Helio S Sader ◽  
Cecilia G Carvalhaes ◽  
Leonard R Duncan ◽  
Robert K Flamm ◽  
Dee Shortridge

Abstract Background The Program to Assess Ceftolozane/Tazobactam Susceptibility (PACTS) monitors the in vitro activity of ceftolozane/tazobactam and numerous antimicrobial agents against Gram-negative bacteria worldwide. Objectives To evaluate the activity of ceftolozane/tazobactam and resistance trends among Pseudomonas aeruginosa and Enterobacterales isolates in Europe between 2012 and 2018. Methods P. aeruginosa (7503) and Enterobacterales (30 582) isolates were collected from 53 medical centres in 26 countries in Europe and the Mediterranean region and tested for susceptibility by reference broth microdilution method in a central laboratory. MIC results were interpreted using EUCAST criteria. Results Ceftolozane/tazobactam was the most active compound tested against P. aeruginosa isolates after colistin, with overall susceptibility rates of 94.1% in Western Europe and 80.9% in Eastern Europe. Moreover, ceftolozane/tazobactam retained activity against 75.2% and 59.2% of meropenem-non-susceptible P. aeruginosa isolates in Western and Eastern Europe, respectively. Tobramycin was the third most active compound tested against P. aeruginosa, with susceptibility rates of 88.6% and 70.9% in Western and Eastern Europe, respectively. Ceftolozane/tazobactam was active against 94.5% of all Enterobacterales and 96.1% of meropenem-susceptible isolates from Western Europe. In Eastern Europe, ceftolozane/tazobactam was active against 79.4% of Enterobacterales overall and 86.2% of meropenem-susceptible isolates. Discussion Antimicrobial susceptibility rates for agents commonly used to treat serious systemic infections varied widely among nations and geographic regions and were generally lower in Eastern Europe compared with Western Europe. Ceftolozane/tazobactam demonstrated potent activity against P. aeruginosa, including MDR strains, and retained activity against most meropenem-susceptible Enterobacterales causing infection in European medical centres.


Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 45 ◽  
Author(s):  
Zehra Edis ◽  
Samir Haj Bloukh

Antibiotic resistance is an eminent threat for the survival of mankind. Nosocomial infections caused by multidrug resistant microorganisms are a reason for morbidity and mortality worldwide. Plant-based antimicrobial agents are based on synergistic mechanisms which prevent resistance and have been used for centuries against ailments. We suggest the use of cost-effective, eco-friendly Aloe Vera Barbadensis Miller (AV)-iodine biomaterials as a new generation of antimicrobial agents. In a facile, one-pot synthesis, we encapsulated fresh AV gel with polyvinylpyrrolidone (PVP) as a stabilizing agent and incorporated iodine moieties in the form of iodine (I2) and sodium iodide (NaI) into the polymer matrix. Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD), microstructural analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) verified the composition of AV-PVP-I2, AV-PVP-I2-NaI. AV, AV-PVP, AV-PVP-I2, AV-PVP-I2-NaI, and AV-PVP-NaI were tested in-vitro by disc diffusion assay and dip-coated on polyglycolic acid (PGA) sutures against ten microbial reference strains. All the tested pathogens were more susceptible towards AV-PVP-I2 due to the inclusion of “smart” triiodides with halogen bonding in vitro and on dip-coated sutures. The biocomplexes AV-PVP-I2, AV-PVP-I2-NaI showed remarkable antimicrobial properties. “Smart” biohybrids with triiodide inclusions have excellent antifungal and promising antimicrobial activities, with potential use against surgical site infections (SSI) and as disinfecting agents.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Gabrielle Sherella Dijksteel ◽  
Peter H. Nibbering ◽  
Magda M. W. Ulrich ◽  
Esther Middelkoop ◽  
Bouke K. H. L. Boekema

Abstract Background Accurate determination of the efficacy of antimicrobial agents requires neutralization of residual antimicrobial activity in the samples before microbiological assessment of the number of surviving bacteria. Sodium polyanethol sulfonate (SPS) is a known neutralizer for the antimicrobial activity of aminoglycosides and polymyxins. In this study, we evaluated the ability of SPS to neutralize residual antimicrobial activity of antimicrobial peptides [SAAP-148 and pexiganan; 1% (wt/v) in PBS], antibiotics [mupirocin (Bactroban) and fusidic acid (Fucidin) in ointments; 2% (wt/wt))] and disinfectants [2% (wt/wt) silver sulfadiazine cream (SSD) and 0.5% (v/v) chlorhexidine in 70% alcohol]. Methods Homogenates of human skin models that had been exposed to various antimicrobial agents for 1 h were pipetted on top of Methicillin-resistant Staphylococcus aureus (MRSA) on agar plates to determine whether the antimicrobial agents display residual activity. To determine the optimal concentration of SPS for neutralization, antimicrobial agents were mixed with PBS or increasing doses of SPS in PBS (0.05–1% wt/v) and then 105 colony forming units (CFU)/mL MRSA were added. After 30 min incubation, the number of viable bacteria was assessed. Next, the in vitro efficacy of SAAP-148 against various gram-positive and gram-negative bacteria was determined using PBS or 0.05% (wt/v) SPS immediately after 30 min incubation of the mixture. Additionally, ex vivo excision wound models were inoculated with 105 CFU MRSA for 1 h and exposed to SAAP-148, pexiganan, chlorhexidine or PBS for 1 h. Subsequently, samples were homogenized in PBS or 0.05% (wt/v) SPS and the number of viable bacteria was assessed. Results All tested antimicrobials displayed residual activity in tissue samples, resulting in a lower recovery of surviving bacteria on agar. SPS concentrations at ≥0.05% (wt/v) were able to neutralize the antimicrobial activity of SAAP-148, pexiganan and chlorhexidine, but not of SSD, Bactroban and Fucidin. Finally, SPS-neutralization in in vitro and ex vivo efficacy tests of SAAP-148, pexiganan and chlorhexidine against gram-positive and gram-negative bacteria resulted in significantly higher numbers of CFU compared to control samples without SPS-neutralization. Conclusions SPS was successfully used to neutralize residual activity of SAAP-148, pexiganan and chlorhexidine and this prevented an overestimation of their efficacy.


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