scholarly journals Synthesis, Antimicrobial Activity and Molecular Docking of Novel Thiourea Derivatives Tagged with Thiadiazole, Imidazole and Triazine Moieties as Potential DNA Gyrase and Topoisomerase IV Inhibitors

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2766 ◽  
Author(s):  
Heba E. Hashem ◽  
Abd El-Galil E. Amr ◽  
Eman S. Nossier ◽  
Elsayed A. Elsayed ◽  
Eman M. Azmy

To develop new antimicrobial agents, a series of novel thiourea derivatives incorporated with different moieties 2–13 was designed and synthesized and their biological activities were evaluated. Compounds 7a, 7b and 8 exhibited excellent antimicrobial activity against all Gram-positive and Gram-negative bacteria, and the fungal Aspergillus flavus with minimum inhibitory concentration (MIC) values ranged from 0.95 ± 0.22 to 3.25 ± 1.00 μg/mL. Furthermore, cytotoxicity studies against MCF-7 cells revealed that compounds 7a and 7b were the most potent with IC50 values of 10.17 ± 0.65 and 11.59 ± 0.59 μM, respectively. On the other hand, the tested compounds were less toxic against normal kidney epithelial cell lines (Vero cells). The in vitro enzyme inhibition assay of 8 displayed excellent inhibitory activity against Escherichia coli DNA B gyrase and moderate one against E. coli Topoisomerase IV (IC50 = 0.33 ± 1.25 and 19.72 ± 1.00 µM, respectively) in comparison with novobiocin (IC50 values 0.28 ± 1.45 and 10.65 ± 1.02 µM, respectively). Finally, the molecular docking was done to position compound 8 into the E. coli DNA B and Topoisomerase IV active pockets to explore the probable binding conformation. In summary, compound 8 may serve as a potential dual E. coli DNA B and Topoisomerase IV inhibitor.

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1078 ◽  
Author(s):  
Silvia Bittner Fialová ◽  
Martin Kello ◽  
Matúš Čoma ◽  
Lívia Slobodníková ◽  
Eva Drobná ◽  
...  

On its own, rosmarinic acid possesses multiple biological activities such as anti-inflammatory, antimicrobial, cardioprotective and antitumor properties, and these are the consequence of its ROS scavenging and inhibitory effect on inflammation. In this study, two quaternary phosphonium salts of rosmarinic acid were prepared for the purpose of increasing its penetration into biological systems with the aim of improving its antimicrobial, antifungal, antiprotozoal and antitumor activity. The synthetized molecules, the triphenylphosphonium and tricyclohexylphosphonium salts of rosmarinic acid, exhibited significantly stronger inhibitory effects on the growth of HCT116 cells with IC50 values of 7.28 or 8.13 μM in comparison to the initial substance, rosmarinic acid (>300 μM). For the synthesized derivatives, we detected a greater than three-fold increase of activity against Acanthamoeba quina, and a greater than eight-fold increase of activity against A. lugdunensis in comparison to rosmarinic acid. Furthermore, we recorded significantly higher antimicrobial activity of the synthetized derivatives when compared to rosmarinic acid itself. Both synthetized quaternary phosphonium salts of rosmarinic acid appear to be promising antitumor and antimicrobial agents, as well as impressive molecules for further research.


Author(s):  
KOSARAJU LAHARI ◽  
RAJA SUNDARARAJAN

Objective: Isatins have emerged as antimicrobial agents due to their broad spectrum of in vitro and in vivo antimicrobial activities. In addition, thiazolidinone also reported to possess various biological activities particularly antimicrobial activity. Due to the importance, we planned to synthesize compounds with isatin functionality coupled with thiazolidinone as possible antitubercular and antimicrobial agents which could furnish better therapeutic results. Methods: In vitro Mycobacterium tuberculosis method and agar streak dilution test are used to estimate antitubercular and antimicrobial potency of title analogs, respectively. Minimum inhibitory concentration of entire title compounds was determined against all tested microorganism such as M. tuberculosis, four Gram-positive, three Gram-negative bacteria, and two fungi. Results: A series of new thiazolidinone substituted Schiff and Mannich bases of 5-nitroisatins were designed and synthesized by a multistep synthesis from isatin. Structures of synthesized compounds are characterized using Fourier-transform infrared, proton nuclear magnetic resonance, mass spectroscopy, and bases of elemental analysis. Mild to good antitubercular and antimicrobial activity was showed by synthesized 5-nitroisatin analogs. The relationship between the biological activity and the functional group variation of the tested compounds was discussed. Conclusion: 3-(4-(3-(4-Aminophenyl)-4-oxothiazolidin-2-yl)phenylimino)-1-((dimethyl amino)methyl)-5-nitroindolin-2-one 6 and 3-(4-(3- (2-aminophenyl)-4-oxothiazolidin-2-yl)phenylimino)-1-((dimethylamino)methyl)-5-nitroindolin-2-one 13 were found to be the most potent compounds of this series which might be extended as a novel class of antimicrobial agents.


Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 730
Author(s):  
Nicolás Gómez-Sequeda ◽  
Marlon Cáceres ◽  
Elena E. Stashenko ◽  
William Hidalgo ◽  
Claudia Ortiz

The emergence of multidrug resistant microorganisms represents a global challenge due to the lack of new effective antimicrobial agents. In this sense, essential oils (EOs) are an alternative to be considered because of their anti-inflammatory, antiviral, antibacterial, and antibiofilm biological activities. Therefore, multiple efforts have been made to consider the potential use of EOs in the treatment of infections which are caused by resistant microorganisms. In this study, 15 EOs of both Colombian and introduced aromatic plants were evaluated against pathogenic strains of E. coli O157:H7 and methicillin resistant Staphylococcus aureus (MRSA) in planktonic and sessile states in order to identify relevant and promising alternatives for the treatment of microbial infections. Forty different compounds were identified in the 15 EO with nine of them constituted mainly by oxygenated monoterpenes (OM). EOs from Lippia origanoides, chemotypes thymol, and carvacrol, displayed the highest antibacterial activity against E. coli O157:H7 (MIC50 = 0.9 and 0.3 mg/mL, respectively) and MRSA (MIC50 = 1.2 and 0.6 mg/mL, respectively). These compounds from EOs had also the highest antibiofilm activity (inhibition percentage > 70.3%). Using scanning electron microscopy (SEM), changes in the size and morphology of both bacteria were observed when they were exposed to sub-inhibitory concentrations of L. origanoides EO carvacrol chemotype. EOs from L. origanoides, thymol, and carvacrol chemotypes represented a viable alternative for the treatment of microbial infections; however, the Selectivity Index (SI ≤ 3) indicated that it was necessary to study alternatives to reduce its in vitro cytotoxicity.


2017 ◽  
Vol 20 (1) ◽  
pp. 41-46
Author(s):  
Dewi Nurul Mustaqimah ◽  
Josh Erry HW

The increasing prevalence of dental caries is still as a major world health problem. Caries is the direct result of acid production by cariogenic oral pathogens, especially Streptococcus mutans. New and better antimicrobial agents active against cariogenic bacteria with minimal side effects on the oral tissues are much needed, especially natural agents derived directly from plants. Phytochemical studies have shown that the extracts from various parts of mangosteen or Garciniamangostana Linn tree contain varieties of secondary metabolites such as prenylated and oxygenated xanthones, many of which have been found in vitro to have antimicrobial properties against oral pathogens. Several studies which examined the eficacy of herbal for human health have shown that xanthones from mangosteen have remarkable biological activities such as antioxidant, antimicrobial, anticancer etc, and had no cytotoxic effects on human gingival fibroblasts. Their results showed that among these xanthone derivatives obtain from pericarp extract of mangosteen, α-mangostin has the most potent antimicrobial activity against cariogenic Streptococcus mutans. It can be concluded that the strong antimicrobial activity of the pericarp extract of mangosteen is a good drug of choice that might be helpful in preventing the dental caries.


2012 ◽  
Vol 550-553 ◽  
pp. 1030-1038
Author(s):  
Peng Li ◽  
Wei Guo Wang ◽  
Yu Jia Cui ◽  
Yong Liang Zhao ◽  
Ya Nan Gu ◽  
...  

Purpose To develop a novel complex antimicrobial agent and determine the optimal components of the composite antimicrobial agents and its antimicrobial activity in vitro. Methods According to antimicrobial mechanisms,antibacterial spectrums,physical and chemical properties and applicabilities of existing antimicrobial agents in clinical use, select out cefoperazone sodium, sulbactam sodium and cephradine as the basic components to make a novel complex antimicrobial agent. Utilize yeast, staphylococcus aureus and E. coli bacteria as test bacteria. Do the three factors four-level orthogonal experiments by the maximum amount, the middle amount, low amount and Minimum amount of the three-component agent to research the optimum ratio of the drug. Measure the titer of the compound antimicrobial agent by the way of tube-plate method (2 doses). With known contents of Penicillin Sodium for Injection as control, and determine its minimum inhibitory concentration against staphylococcus aureus, E. coli and yeast by using the agar doubling dilution method. The experimental results were analysized by statistical analysis software SPSS16.0. Results The results of the three factors four-level orthogonal experiments indicate the optimum ratios of Cefoperazone Sodium, Sulbactam Sodium and Cephradine against E. coli, yeast and staphylococcus aureus were 2:2:3, 1:2:2 and 2:6:5, their titers were 1353.9U/mg, 982.7U/mg and 1015.5U/mg. With the highest titer proportion 2:2:3 as the composition of the antimicrobial compound. This compound antimicrobial agent had a good antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and Fungi, its minimal inhibitory concentration (MIC) against staphylococcus aureus, E. coli and yeast were 2.000μg/ml, 0.500μg/ml and 16.000μg/ml. Conclusion This research acquires a composite of antibiotics. This antimicrobial compound has a broader spectrum and higher antimicrobial activity in vitro comparing with traditional common single antibiotics, and it especially has a good antimicrobial activity against fungi. The results set a scientific foundation for enriching clinical medicines.


2021 ◽  
Vol 14 (5) ◽  
pp. 399
Author(s):  
Lamya H. Al-Wahaibi ◽  
Amer A. Amer ◽  
Adel A. Marzouk ◽  
Hesham A.M. Gomaa ◽  
Bahaa G. M. Youssif ◽  
...  

A novel series of ciprofloxacin hybrids comprising various heterocycle derivatives has been synthesized and structurally elucidated using 1H NMR, 13C NMR, and elementary analyses. Using ciprofloxacin as a reference, compounds 1–21 were screened in vitro against Gram-positive bacterial strains such as Staphylococcus aureus and Bacillus subtilis and Gram-negative strains such as Escherichia coli and Pseudomonas aeruginosa. As a result, many of the compounds examined had antibacterial activity equivalent to ciprofloxacin against test bacteria. Compounds 2–6, oxadiazole derivatives, were found to have antibacterial activity that was 88 to 120% that of ciprofloxacin against Gram-positive and Gram-negative bacteria. The findings showed that none of the compounds tested had antifungal activity against Aspergillus flavus, but did have poor activity against Candida albicans, ranging from 23% to 33% of fluconazole, with compound 3 being the most active (33% of fluconazole). The most potent compounds, 3, 4, 5, and 6, displayed an IC50 of 86, 42, 92, and 180 nM against E. coli DNA gyrase, respectively (novobiocin, IC50 = 170 nM). Compounds 4, 5, and 6 showed IC50 values (1.47, 6.80, and 8.92 µM, respectively) against E. coli topo IV in comparison to novobiocin (IC50 = 11 µM).


2020 ◽  
Vol 8 (1) ◽  
pp. 7-14
Author(s):  
Turgut Taşkın ◽  
Eray M. Güler ◽  
Şeyda Şentürk ◽  
Damla D. Çelik ◽  
Turan Arabacı ◽  
...  

Background: The genus Achillea is one of the most important genus of the Asteraceae family and many species of Achillea are used in traditional medicine to treat several ailments. Aim: The aim of the current research was to evaluate in vitro cytotoxic activities of n-hexan, chloroform, ethyl acetate and methanol extracts and to isolate the active compounds from the extract showing the strongest cytotoxic activity. In addition to this, it was aimed to evaluate the biological activities (cytotoxic, antioxidant, anti-urease, anticholinesterase, antimicrobial) of different extracts and active compounds from Achillea monocephala. Methods and Materials: The in vitro antioxidant, cytotoxic, anti-urease, anticholinesterase and antimicrobial activities of different extracts from A. monocephala aerial parts were examined. The structures of the active compounds were determined by NMR techniques, UV, IR and LC-MS/MS analysis and their biological potential was examined. Results: The chloroform extract showed strong and selective cytotoxic activity on the cancer cell lines (MDA-MB-231, MCF-7). Besides, this extract exhibited stronger antimicrobial activity than other extracts. Therefore, through activity-guided procedures, luteolin, naringenin and 8-hydroxy-salvigenin compounds were isolated from this extract. The methanol extract showed stronger antioxidant (DPPH, ABTS, CUPRAC) and anticholinesterase activity than other extracts. The n-hexan extract exhibited the highest anti-urease activity. In this study, it was determined that the isolated compounds had a strong biological activity. Naringenin compound had stronger ABTS radical cation scavenging and ferric reducing/antioxidant power, cytotoxic and antimicrobial activity than other compounds. 8-hydroxy-salvigenin compound showed the highest urease and acetylcholinestease enzyme inhibition. Conclusion: The results of this study suggest that the extracts and isolated compounds from the A. monocephala may be used as antioxidant, cytotoxic, anti-urease, anticholinesterase and antimicrobial agents in the future.


Author(s):  
V. V. Pantyo ◽  
M. M. Fizer ◽  
O. I. Fizer ◽  
G. M. Koval ◽  
E.M. Danko

Annotation. The development and rapid pace of the spread of resistance to antimicrobial agents predetermines the search for new methods of counteracting pathogenic and conditionally pathogenic microorganisms. In this context, studies of the antimicrobial activity of newly synthesized chemicals, which in the future can be considered as candidates for antiseptic and disinfectants, are relevant. The aim of the work was to determine the antimicrobial activity of new ionic associates based on the surface-active cetylpyridinium cation with respect to certain opportunistic microorganisms. The antimicrobial activity of four ionic associates based on the cetylpyridinium cation with respect to clinical isolates of E. coli, P. vulgaris, K. pneumonia, P. aeruginosa, S. aureus, as well as the collection test strains of S. aureus ATCC 25923, E. coli ATCC 29522 and P. aeruginosa ATCC 27853 was studied. Screening studies were performed by the disk diffusion method. With substances that showed an antimicrobial effect, quantitative studies were carried out by the method of serial macro-dilutions in a liquid nutrient media. Screening studies revealed the antibacterial activity of the substances against E. coli ATCC 25923, E. coli (clinical isolate), P. vulgaris and K. pneumonia. With these microorganisms quantitative studies were carried out with the determination of the minimum inhibitory and minimum bactericidal concentrations. The most pronounced antimicrobial activity for the investigated microflora was shown by tetraphenylborate and cetylpyridinium perchlorate. The MIC and MBC values of these substances ranged between 1.625–3.125 mmol / L and 3.125–12.5 mmol / L, respectively. The studied associates showed high antimicrobial activity against representatives of the Enterobacteriaceae family in in vitro studies. Promising is the further study of the effect of the counter-anion associates of cationic surfactants on the biofilm formation of conditionally pathogenic microorganisms.


Author(s):  
Abu- Safieh Rana ◽  
Muhi- Eldeen Zuhair ◽  
Alsarahni Aseel ◽  
Al-Kaissi Elham

A new series of 7-methoxy-2-[4-(t-amino-1-yl)oxy]-naphthalene derivatives; 7-methoxy-2-{[4-(2-methylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ2), 7-methoxy-2-{[4-(2,6-dimethylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ3), 7-methoxy-2{[4-(piperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ4), 7-methoxy-2-{[4-(pyrrolidine)but-2-yn-1-yl]oxy}-naphthalene (RZ5), 7-methoxy-2-{[4-(N-methylpiperazine)but-2-yn-1-yl]oxy}-naphthalene (RZ6), 7-methoxy -2-{[4-(hexamethyleneimine)but-2-yn-1-yl]oxy}-naphthalene (RZ7) were synthesized and screened in vitro as potential antimicrobial agents. Antimicrobial activity were evaluated by measuring the minimum inhibitory and bactericidal/fungicidal concentration (MIC, MBC and MFC). RZ2, RZ5, RZ6 and RZ7 showed the highest antimicrobial activity against S. aureus with MIC value 62.5 µg/ml, compounds RZ2, RZ4, RZ5, and RZ7 have the highest antimicrobial activity against B. subtilis with MIC vale 62.5 µg/ml, RZ3, RZ6 have the same antimicrobial activity with MIC value 125µg/ml, compounds. RZ4, RZ5, RZ6 and RZ7 have the highest antimicrobial activity against E. coli with MIC value 125 µg/ml, all compounds have the same MIC value against P. aeruginosa (125 µg/ml). RZ2, RZ4, RZ5, RZ6, RZ7 showed the highest antifungal activity with MIC of 62.5 µg/ml. In conclusion, the synthesized compounds showed good antimicrobial activity and promising potency against gram positive bacteria, gram negative bacteria and fungi.


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