Design, Synthesis and Antibacterial Evaluation of Novel 1,2,3-Triazole Derivatives Incorporating 3′-Deoxythymidine

2017 ◽  
Vol 41 (11) ◽  
pp. 645-649 ◽  
Author(s):  
Long-Fei Mao ◽  
Gui-Qing Xu ◽  
Bin Sun ◽  
Yu-Qin Jiang ◽  
Wen-Pei Dong ◽  
...  

A series of novel 1,2,3-triazole derivatives incorporating 3′-deoxythymidine were designed, synthesised and characterised. Antibacterial activity against Escherichia coli and Staphylococcus aureus was evaluated for all of the synthesised compounds and compared against standard antibiotic drugs, streptomycin sulfate and doxycycline, as controls. Some compounds showed potential antibacterial activity towards E. coli, and the best minimum inhibitory concentration was 0.14 mM. Preliminary structure-activity relationships and computational simulations were also studied.

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2126 ◽  
Author(s):  
Alla V. Lipeeva ◽  
Danila O. Zakharov ◽  
Liubov G. Burova ◽  
Tatyana S. Frolova ◽  
Dmitry S. Baev ◽  
...  

Synthesis of 1,2,3-triazole-substituted coumarins and also 1,2,3-triazolyl or 1,2,3-triazolylalk-1-inyl-linked coumarin-2,3-furocoumarin hybrids was performed by employing the cross-coupling and copper catalyzed azide-alkyne cycloaddition reaction approaches. The synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, Bacillius subtilis, Actinomyces viscosus and Escherichia coli bacterial strains. Coumarin-benzoic acid hybrids 4с, 42с and 3-((4-acetylamino-3-(methoxycarbonyl)phenyl)ethynyl)coumarin (29) showed promising activity against S. aureus strains, and the 1,2,3-triazolyloct-1-inyl linked coumarin-2,3-furocoumarin hybrid 37c was endowed with high selectivity against B. subtilis and E. coli species. The in vitro antibacterial activity of 4с, 29, 37c and 42с can potentially be compared with that of a number of modern antibiotic drugs used in the clinic, suggesting promising prospects for further research. A detailed study of the molecular interactions with the targeted protein MurB was performed using docking simulations and the obtained results are quite promising.


2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.


2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.


Author(s):  
Olufunmiso O. Olajuyigbe ◽  
Morenike O. Adeoye-Isijola ◽  
Otunola Adedayo

Background: Black soap is a medicinal product that could be harnessed for economic purpose if properly packaged, and misconception about its traditional use by herbalists is thrown overboard.Aims: To promote the relevance of these soaps for economic development, this study compared the antibacterial activity of black soaps with medicated soaps widely used against bacterial infections.Methods: The antibacterial activities of these soap samples were determined by agar diffusion and macrobroth dilution methods.Results: In this study, the statistical analysis of the inhibition zones showed that black soaps were significantly (p < 0.05) more active than medicated soaps used against the test bacterial isolates. The black soaps inhibited and killed the isolates better than the medicated soaps at the different concentrations used. The minimum inhibitory concentration for Klebsiella pneumoniae and Enterococcus faecalis ranged between 0.125 mg/mL and 2 mg/mL, Staphylococcus aureus (0.25–4) mg/mL, Escherichia coli (0.125–4) mg/mL and Pseudomonas aeruginosa (1–4) mg/mL. The result showed that K. pneumoniae and E. faecalis were the most susceptible, followed by E. faecalis > E. coli > S. aureus > P. aeruginosa.Conclusion: As a valuable medicinal output derivable from organic waste product that could be converted to wealth, African black soap production, utilisation and commercialisation have tremendous economic potentials. These soaps showed significant antibacterial activity greater than those of the medicated soaps. Hence, their use could be a better option in place of commercially available medicated and antiseptic soaps because of the degree of antibacterial activities they exhibited.


2008 ◽  
Vol 414 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Ruud P. M. Dings ◽  
Judith R. Haseman ◽  
Kevin H. Mayo

Cationic peptides, known to disrupt bacterial membranes, are being developed as promising agents for therapeutic intervention against infectious disease. In the present study, we investigate structure–activity relationships in the bacterial membrane disruptor βpep-25, a peptide 33-mer. For insight into which amino acid residues are functionally important, we synthesized alanine-scanning variants of βpep-25 and assessed their ability to kill bacteria (Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus) and to neutralize LPS (lipopolysaccharide). Activity profiles were found to vary with the bacterial strain examined. Specific cationic and smaller hydrophobic alkyl residues were crucial to optimal bactericidal activity against the Gram-negative bacteria, whereas larger hydrophobic and cationic residues mediated optimal activity against Gram-positive Staph. aureus. Lysine-substituted norleucine (n-butyl group) variants demonstrated that both charge and alkyl chain length mediate optimal activity. In terms of LPS neutralization, activity profiles were essentially the same against four species of LPS (E. coli 055 and 0111, Salmonella enterica serotype Typhimurium and Klebsiella pneumoniae), and different for two others (Ps. aeruginosa and Serratia marcescens), with specific hydrophobic, cationic and, surprisingly, anionic residues being functionally important. Furthermore, disulfide-bridged analogues demonstrated that an anti parallel β-sheet structure is the bioactive conformation of βpep-25 in terms of its bactericidal, but not LPS endotoxin neutralizing, activity. Moreover, βpep-25 variants, like the parent peptide, do not lyse eukaryotic cells. This research contributes to the development and design of novel antibiotics.


2019 ◽  
Vol 10 (2) ◽  
pp. 1136-1142
Author(s):  
Athraa H Mekky ◽  
Sajida M Thamir

The aim of the study is to synthesise and. Characterize — some novel, "tetrazole., -5-thiol” derivatives. Firstly, the “1-phenyl-1H7-tetrazole-5-thiol” (A1) has been., synthesised by the reaction of phenylisothiocyanate with NaN3 in water as a solvent. Secondly, the tetrazole-5-thiol derivatives (A2-A4) were synthesised by the alkylation reaction of the compound (A1) with chloroacetone, phenacyl bromide and chloromethyl acetate respectively. The resulted percentage yield was relatively high (92%, %95, %90 respectively). Compound (A5) was synthesised by the reaction of ethyl acetate tetrazole derivative (A4) with hydrazine. Moreover, the derivatives (A6-A11) were synthesised by the reaction of the (A5) with various substituted aromatic aldehydes. Moreover, compounds (A12-A13) have been synthesised by the cyclization reaction of compound A5 with acetylacetone and phenyl acetylacetone respectively. The produced compounds have been identified by IR, 13C-NMR and 1H-NMR Spectroscopy, and the quantities of various of the physical data (melting point, the shape of crystal and color). Finally, the compounds were examined for their biological activities alongside two kinds of bacteria (E. Coli and Staphylococcus aureus). Compounds A2, A4, A8, A11 and A13 showed the highest inhibition activity against E. Coli. Compounds A2, A9, A10and A13 showed the maximum activity against Staphylococcus aureus.


2020 ◽  
Vol 26 (6) ◽  
pp. 200454-0
Author(s):  
Sabaoon Shamshad ◽  
Jamshaid Rashid ◽  
Ihsan-ul-haq ◽  
Naseem Iqbal ◽  
Saif Ullah Awan

Multidrug resistance of bacteria is an emerging human health hazard and warrants development of novel antibacterial agents with more effective mode of action. Here, zinc oxide and silver nanomaterials were prepared using Ficus palmata Forssk leaf extract with efficient antibacterial activity. SEM coupled with EDS confirmed the spherical symmetry with average particle diameter 50 to 65 nm while the XRD confirmed crystalline face centered cubic structure of silver and hexagonal crystallize phase of zinc oxide nanoparticles. Antibacterial activity was evaluated for 8 pathogenic bacterial strains including 3 drug resistant pathogenic strains. The nanoparticles showed enhanced growth inhibition for resistant strains in comparison with the broad-spectrum antibiotics i.e. roxithromycin and cefixime. Minimum inhibitory concentration in μg.mL<sup>-1</sup> of silver nanoparticles was found to be as low as 33.3 for resistant Streptococcus haemolyticus; 11.1 for Staphylococcus aureus and E Coli; and 3.7 μg.mL<sup>-1</sup> for resistant Pseudomonas aeruginosa. Similarly, the minimum inhibitory concentration of zinc oxide nanoparticles was found to be 100 μg.mL<sup>-1</sup> against resistant Streptococcus haemolyticus and Staphylococcus aureus; 11.1 μg.mL<sup>-1</sup> for resistant Pseudomonas aeruginosa; and 3.7 μg.mL<sup>-1</sup> against resistant E coli. Ficus palmata Forssk leaf extracts can be explored effectively for synthesizing active antibacterial nanomaterials as a non-toxic and environmentally benign synthesis route.


2021 ◽  
Vol 45 (11-12) ◽  
pp. 1093-1099
Author(s):  
Abdulrhman Alsayari ◽  
Yahya I Asiri ◽  
Abdullatif Bin Muhsinah ◽  
Mohd. Zaheen Hassan

We report the design, synthesis, and in vitro antimicrobial evaluation of functionalized pyrazoles containing a hydrazono/diazenyl moiety. Among these newly synthesized derivatives, 4-[2-(4-chlorophenyl)hydrazono]-5-methyl-2-[2-(naphthalen-2-yloxy)acetyl]-2,4-dihydro-3 H-pyrazol-3-one is a promising antimicrobial agent against Staphylococcus aureus (minimum inhibitory concentration 0.19 μg mL−1). Structure–activity relationship studies reveal that the electronic environment on the distal phenyl ring has a considerable effect on the antimicrobial potential of the hybrid analogues. Molecular docking studies into the active site of S. aureus dihydrofolate reductase also prove the usefulness of hybridizing a pyrazole moiety with azo and hydrazo groups in the design of new antimicrobial agents.


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