scholarly journals ANTIMICROBIAL ACTIVITY STUDY OF NEW QUINAZOLIN-4(3H)-ONES AGAINST STAPHYLOCOCCUS AUREUS AND STREPTOCOCCUS PNEUMONIAE

2021 ◽  
Vol 9 (4) ◽  
pp. 318-329
Author(s):  
M. A. Samotrueva ◽  
A. A. Ozerov ◽  
A. A. Starikova ◽  
N. M. Gabitova ◽  
D. V. Merezhkina ◽  
...  

Quinazolin-4(3H)-one derivatives exhibiting a wide spectrum of a pharmacological activity, represent a promising class of substances used to obtain antibacterial agents, which is especially important in the context of the emergence of pathogenic microorganisms’ resistance to drugs used in medicine. It has been proved that compounds having a naphthyl radical in the molecule, as well as an amide group bound to the benzene ring as quinazolinone substituents, are characterized by a pronounced antimicrobial activity against Staphylococcus aureus and Streptococcus pneumoniae.The aim of the research is a primary microbiological screening of the in vitro antimicrobial activity of new quinazolin-4(3H)-one derivatives against Staphylococcus aureus and Streptococcus pneumoniae, as well as the assessment of the relationship between the pharmacological effect and the structural transformation of the substance molecule, lipophilicity and the possibility of forming resistance to them.Materials and methods. The experimental studies have been carried out using well-known nosocomial pathogens of infectious and inflammatory diseases Staphylococcus aureus and Streptococcus pneumoniae by a serial dilution method.Results. A compound containing a naphthyl radical in its structure, which contributes to an increase in the hydrophobicity of the substance and its solubility in the membrane of a bacterial cell, has a bacteriostatic effect against both Staphylococcus aureus and Streptococcus pneumoniae. A similar pharmacological effect is exhibited by a derivative with an amide group as a substituent of the quinazolinone nucleus linked to a phenyl radical, which probably contributes to an increase in the degree of binding to active sites of enzymes involved in the DNA replication, and protein synthesis. Obviously, the increased lipophilicity, which promotes better binding to the efflux protein, cannot serve as objective characteristics of the emergence possibility of the pathogen’s resistance to this substance.Conclusion. Among the synthesized compounds, the leading substances that exhibit an antimicrobial activity against Staphylococcus aureus and Streptococcus pneumonia, have been identified. The assessment of the chemical structure made it possible to substantiate their pharmacological action and draw conclusions about the possibility of developing resistance to it in microbial cells.

2002 ◽  
Vol 46 (3) ◽  
pp. 892-895 ◽  
Author(s):  
Carmen Betriu ◽  
Iciar Rodríguez-Avial ◽  
Blas Ali Sánchez ◽  
María Gómez ◽  
Juan Álvarez ◽  
...  

ABSTRACT The antimicrobial activities of tigecycline (GAR-936) were compared with those of other agents against 1,087 strains recently isolated in 12 Spanish medical centers. Tigecycline showed activity against a wide spectrum of aerobic and anaerobic bacteria, including strains such as methicillin-resistant Staphylococcus aureus, coagulase-negative staphylococci, penicillin-resistant Streptococcus pneumoniae, Enterococcus faecium, Acinetobacter baumannii, and Stenotrophomonas maltophilia.


Author(s):  
Sharma V ◽  
Lobo R. ◽  
Singh G. ◽  
Chanana V. ◽  
Kalsi V. ◽  
...  

Objective: The present work is an attempt to assess the in vitro antimicrobial activity of the leaves of Caesalpinia decapetala (Roth) fabaceae family collected from forest area of Tamilnadu, India. Methods: The crude drug was successively extracted by Soxhlet assembly using Petroleum ether, dichloromethane, ethyl acetate and methanol as solvents. Preliminary phytochemical screening of different extracts was carried out using several colour and precipitative chemical reagents as per described methods. Antimicrobial activity of the extracts was evaluated against fungal strains (Aspergillus fumigatus and Candida albicans), Gram +ve bacteria (Staphylococcus aureus and Streptococcus pyogenes) and Gram –ve bacteria (Escherichia coli and Pseudomonas aeruginosa) using agar wells dilution method. Nutrient agar medium at37 oC and sabouraud dextrose e agar medium at 28 oC were used in antimicrobial activity evaluation and antifungal activity evaluation respectively. Results: Preliminary phytochemical screening of C. decepetala leaves showed the presence of alkaloids, glycosides, phenols, phytosterols, saponins and flavonoids crude drug. C. decapetala leaf extracts exhibited marked dose dependent antibacterial activity in vitro against tested bacteria. Methanolic extract was found to be more potent particularly against Staphylococcus aureus (Gram +ve bacteria) and staphylococcus aeruginosa (Gram -ve bacteria). Conclusion: Various phytochemicals were found to be present in C. decepetala leaves. Methanolic extract of C. decepetala leaves exhibited better antimicrobial activity in vitro and can be used as a good therapeutic approach for infectious disease management and therapy. Further studies on isolation of phyto-constituents and both in vitro and in vivo evaluation of pharmacological activities of isolated bioactive constituents of the crude drug are recommended as future works.


2020 ◽  
Author(s):  
Sumana Bhowmick ◽  
Rafael Baptista ◽  
David Fazakerley ◽  
Kezia E. Whatley ◽  
Karl F. Hoffmann ◽  
...  

AbstractThe discovery of antimalarial artemisinin from Artemisia annua L. is an example of how Traditional Chinese Medicine (TCM) may be exploited to meet a recognized need. In this study, we systemically investigated A. annua L. for its antimicrobial activity and assessed it as a source of bioactive natural products for anti-mycobacterial activity.We used a silica gel column to perform antimicrobial activity-guided purification of the A. annua leaf, whose identity was confirmed by rbcL DNA barcoding, and used UHPLC-HRMS and NMR to elucidate the structure of purified active compounds. The antimicrobial activity of crude extracts, isolated compounds and the control artemisinin (Apollo Scientific Ltd) was assessed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Mycobacterium smegmatis strains by serial micro dilution method (31.25-1000 μg/mL). The isolated compounds were tested for synergistic effects against mycobacterium.Bioactive compounds were purified and identified as deoxyartemisinin and artemisinic acid. Artemisinic acid (MIC 250 μg/mL) was more effective in comparison to deoxyartemisinin (MIC 500 μg/mL) and artemisinin (MIC 1000 μg/mL) against M. smegmatis. We used a molecular docking approach to investigate the interactions between selected anti-mycobacterial compounds and proteins involved in vital physiological functions in M. tuberculosis, namely MtPks13, MtPknB, MtPanK, MtKasA, MtInhA and MtDprE1 and found artemisinic acid showed docking scores superior to the control inhibiters for MtKasA, suggesting it to be a potential nick for further in vitro biological evaluation and anti-TB drug design.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mehul M. Patel ◽  
Laxman J. Patel

Objective. Quinolone moiety is an important class of nitrogen containing heterocycles widely used as key building blocks for medicinal agents. It exhibits a wide spectrum of pharmacophores and has bactericidal, antiviral, antimalarial, and anticancer activities. In view of the reported antimicrobial activity of various fluoroquinolones, the importance of the C-7 substituents is that they exhibit potent antimicrobial activities. Our objective was to synthesize newer quinolone analogues with increasing bulk at C-7 position of the main 6-fluoroquinolone scaffold to produce the target compounds which have potent antimicrobial activity.Methods. A novel series of 1-ethyl-6-fluoro-4-oxo-7-{4-[2-(4-substituted phenyl)-2-(substituted)-ethyl]-1-piperazinyl}-1,4-dihydroquinoline-3-carboxylic acid derivatives were synthesized. To understand the interaction of binding sites with bacterial protein receptor, the docking study was performed using topoisomerase II DNA gyrase enzymes (PDB ID: 2XCT) by Schrodinger’s Maestro program.In vitroantibacterial activity of the synthesized compounds was studied and the MIC value was calculated by the broth dilution method.Results. Among all the synthesized compounds, some compounds showed potent antimicrobial activity. The compound8gexhibited good antibacterial activity.Conclusion. This investigation identified the potent antibacterial agents against certain infections.


2021 ◽  
Vol 11 (5-S) ◽  
pp. 63-70
Author(s):  
G'massampou Datagni ◽  
Aklesso Pouwelong Mouzou ◽  
Kossi Metowogo ◽  
Yaovi-Gameli Afanyibo ◽  
Adodo Sadji ◽  
...  

Annona senegalensis and Securidaca longepedunculata are two plants traditionnaly used in inflammation and wounds infection treatment after snakebites. This study aims to investigate the in vitro anti-inflammatory and antimicrobial activities of the hydroalcoholic extracts of Annona senegalensis and Securidaca longepedunculata. Antimicrobial activity of the two plant extracts was examined against five bacterial strains with the well diffusion method and the inhibition zones diameters (IZD), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the 96-well microplate dilution method. While antiinflammatory activity was assessed by the albumin denaturation method. The results obtained showed that the hydroalcoholic extract of Annona senegalensis has antimicrobial property against Staphylococcus aureus (IZD=12.22 ± 0.24 mm, MIC=62.5 mg/mL, MBC=125 mg/mL) and against Pseudomonas aeruginosa (IZD=12.06 ± 0.06 mm, MIC=125 mg/mL, MBC=250 mg/mL). Securidaca longepedunculata also showed its antimicrobial activity against Staphylococcus aureus (IZD=12.03 ± 0.03 mm, MIC=125 mg/mL, MBC=250 mg/mL) and Candida albicans (IZD=12.12 ± 0.07 mm, MIC=62.5 mg/mL, MFC=125 mg/mL). In the order hand,  Annona senegalensis and Securidaca longepedunculata exhibited concentration-dependent anti-inflammatory activity by reducing significantly (p<0.001)  the denaturation of BSA. In addition  S. longepedunculata inhibited haemolysis significantly (p<0.001) more than Diclofenac sodium at 200 and 400 µg/mL. Hence, it was concluded that Annona senegalensis and Securidaca longepedunculata possessed anti-inflammatory and antimicrobial properties and can be used in the treatment of inflammation and wounds infection after snakebites. Keywords: Annona senegalensis, Securidaca longepedunculata, anti-inflammatory, antimicrobial, BSA.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 751
Author(s):  
Marwa Reda Bakkar ◽  
Ahmed Hassan Ibrahim Faraag ◽  
Elham R. S. Soliman ◽  
Manar S. Fouda ◽  
Amir Mahfouz Mokhtar Sarguos ◽  
...  

COVID-19 is a pandemic disease caused by the SARS-CoV-2, which continues to cause global health and economic problems since emerging in China in late 2019. Until now, there are no standard antiviral treatments. Thus, several strategies were adopted to minimize virus transmission, such as social distancing, face covering protection and hand hygiene. Rhamnolipids are glycolipids produced formally by Pseudomonas aeruginosa and as biosurfactants, they were shown to have broad antimicrobial activity. In this study, we investigated the antimicrobial activity of rhamnolipids against selected multidrug resistant bacteria and SARS-CoV-2. Rhamnolipids were produced by growing Pseudomonas aeruginosa strain LeS3 in a new medium formulated from chicken carcass soup. The isolated rhamnolipids were characterized for their molecular composition, formulated into nano-micelles, and the antibacterial activity of the nano-micelles was demonstrated in vitro against both Gram-negative and Gram-positive drug resistant bacteria. In silico studies docking rhamnolipids to structural and non-structural proteins of SARS-CoV-2 was also performed. We demonstrated the efficient and specific interaction of rhamnolipids with the active sites of these proteins. Additionally, the computational studies suggested that rhamnolipids have membrane permeability activity. Thus, the obtained results indicate that SARS-CoV-2 could be another target of rhamnolipids and could find utility in the fight against COVID-19, a future perspective to be considered.


2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.


2014 ◽  
Vol 44 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Carolinie Batista Nobre da Cruz ◽  
Fabio Alessandro Pieri ◽  
Gislene Almeida Carvalho-Zilse ◽  
Patrícia Puccinelli Orlandi ◽  
Carlos Gustavo Nunes-Silva ◽  
...  

Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Müller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.


Biotemas ◽  
2017 ◽  
Vol 30 (2) ◽  
pp. 25
Author(s):  
Rodrigo Rafael Maia ◽  
Andréia Vieira Pereira ◽  
Marcelo Biondaro Góis ◽  
Karine Delgado Souza ◽  
Vanessa De Melo Cavalcanti-Dantas ◽  
...  

http://dx.doi.org/10.5007/2175-7925.2017v30n2p25O surgimento de infecções bacterianas, incluindo aquelas associadas com Staphylococcus aureus, traz à tona uma necessidade de buscar novas estratégias mais eficazes para tratamento clínico. O uso de plantas medicinais associados com os antibióticos convencionais pode ser uma opção terapêutica. Atualmente, estudos evidenciam o efeito sinérgico alcançado através da combinação de extratos vegetais com antibióticos. Nosso objetivo foi avaliar a atividade antimicrobiana e cinética bacteriana in vitro do extrato de Matricaria recutita (camomila) e sua associação com cefalexina e norfloxacin sobre isolados clínicos de S. aureus de origem bovina, caracterizada como resistente. Os ensaios foram realizados pelo método da diluição em meio sólido para a determinação da Concentração Inibitória Mínima (CIM). Em ambas as associações do extrato de M. recutita com os antibióticos norfloxacina e cefalexina, foi observada CIM na diluição 1:64 o que correspondeu a 8μg/mL dos antibióticos e 13.43 μg/mL do extrato. A associação Cefalexina com extrato de camomila produziu um efeito sinérgico em 75% das amostras na sua CIM. A combinação com produtos naturais frequentemente utilizados pela população e os antibióticos aqui ensaiados, poderiam representar uma opção terapêutica para o tratamento de infecções causadas por S. aureus, como também para prevenção do desenvolvimento crescente de resistência.


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