scholarly journals Synthesis, Molecular Docking Analysis, and Evaluation of Antibacterial and Antioxidant Properties of Stilbenes and Pinacol of Quinolines

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Zeleke Digafie ◽  
Yadessa Melaku ◽  
Zerihun Belay ◽  
Rajalakshmanan Eswaramoorthy

Emergence of antimicrobial resistance to standard commercial drugs has become a critical public health concern worldwide. Hence, novel antimicrobials with improved biological activities are urgently needed. In this regard, a series of quinoline-stilbene derivatives were synthesized from substituted quinoline and benzyltriphenylphosphonium chloride using Wittig reaction. Furthermore, a novel pinacol of quinoline was synthesized by pinacolinazation of 2-methoxyquinoline-3-carbaldehyde which was achieved by aluminum powder-potassium hydroxide reagent combination at ambient temperature in methanol. The structures of the synthesized compounds were established based on their spectral data. The antibacterial activities of the synthesized compounds were evaluated in vitro by the paper disc diffusion method against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative bacteria (Escherichia coli and Salmonella typhimurium). The best activity was displayed by compound 19 against E. coli with an inhibition zone of 16.0 ± 0.82 mm and 14.67 ± 0.94 mm at 500 and 250 μg/mL, respectively. This is close to ciprofloxacin which is used as a positive control. The results of in silico molecular docking evaluation of the compounds against E. coli DNA gyraseB were in good agreement with the in vitro antibacterial analysis. Compounds 19 (−6.9 kcal/mol) and 24 (−7.1 kcal/mol) showed the maximum binding affinity close to ciprofloxacin (−7.3 kcal/mol) used as positive control. Therefore, the antibacterial activity displayed by these compounds is encouraging for further investigation to improve the activities of quinoline-stilbenes by incorporating various bioisosteric groups in one or more positions of the phenyl nuclei for their potential pharmacological use. Findings of the DPPH radical scavenging assay indicated that some of the quinolone stilbenes and pinacol possess moderate antioxidant properties compared to ascorbic acid used as a natural antioxidant.

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bayan Abdi ◽  
Mona Fekadu ◽  
Digafie Zeleke ◽  
Rajalakshmanan Eswaramoorthy ◽  
Yadessa Melaku

Quinoline heterocycle is a useful scaffold to develop bioactive molecules used as anticancer, antimalaria, and antimicrobials. Inspired by their numerous biological activities, an attempt was made to synthesize a series of novel 7-chloroquinoline derivatives, including 2,7-dichloroquinoline-3-carbonitrile (5), 2,7-dichloroquinoline-3-carboxamide (6), 7-chloro-2-methoxyquinoline-3-carbaldehyde (7), 7-chloro-2-ethoxyquinoline-3-carbaldehyde (8), and 2-chloroquinoline-3-carbonitrile (12) by the application of Vilsmeier–Haack reaction and aromatic nucleophilic substitution of 2,7-dichloroquinoline-3-carbaldehyde. The carbaldehyde functional group was transformed into nitriles using POCl3 and NaN3, which was subsequently converted to amide using CH3CO2H and H2SO4. The compounds synthesized were screened for their antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Streptococcus pyogenes. Compounds 6 and 8 showed good activity against E. coli with an inhibition zone of 11.00 ± 0.04 and 12.00 ± 0.00 mm, respectively. Compound 5 had good activity against S. aureus and P. aeruginosa with an inhibition zone of 11.00 ± 0.03 mm relative to standard amoxicillin (18 ± 0.00 mm). Compound 7 displayed good activity against S. pyogenes with an inhibition zone of 11.00 ± 0.02 mm. The radical scavenging activity of these compounds was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), and compounds 5 and 6 displayed the strongest antioxidant activity with IC50 of 2.17 and 0.31 µg/mL relative to ascorbic acid (2.41 µg/mL), respectively. The molecular docking study of the synthesized compounds was conducted to investigate their binding pattern with topoisomerase IIβ and E. coli DNA gyrase B. Compounds 6 (−6.4 kcal/mol) and 8 (−6.6 kcal/mol) exhibited better binding affinity in their in silico molecular docking against E. coli DNA gyrase. The synthesized compounds were also found to have minimum binding energy ranging from −6.9 to −7.3 kcal/mol against topoisomerase IIβ. The SwissADME predicted results showed that the synthesized compounds 5–8 and 12 satisfy Lipinski’s rule of five with zero violations. The ProTox-II predicted organ toxicity results revealed that all the synthesized compounds were inactive in hepatotoxicity, immunotoxicity, mutagenicity, and cytotoxicity. The findings of the in vitro antibacterial and molecular docking analysis suggested that compound 8 might be considered a hit compound for further analysis as antibacterial and anticancer drug. The radical scavenging activity displayed by compounds 5 and 6 suggests these compounds as a radical scavenger.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yoseph Samuel ◽  
Ankita Garg ◽  
Endale Mulugeta

Synthetic modifications of sulfathiazole derivatives become an interesting approach to enhance their biological properties in line with their applications. As a result, sulfathiazole derivatives become a good candidate and potential class of organic compounds to play an important role towards medicinal chemistry. In present study, one thiazole derivative and two new sulfathiazole derivatives are synthesized with 94% and 72–81% yields, respectively. Furthermore, the synthesized compounds were evaluated for their in vitro antibacterial activity against two Gram-negative (E. coli and P. aeruginosa) and two Gram-positive bacterial strains (S. pyogenes and S. aureus) by disk diffusion method. Among synthesized compounds, compound 11a showed potent inhibitory activity against Gram-negative, E. coli with 11.6 ± 0.283 mm zone of inhibition compared to standard drug sulfamethoxazole (15.7 ± 0.707 mm) at 50 mg/mL. The radical scavenging activities of these compounds were evaluated using DPPH radical assay, and compound 11a showed the strongest activity with IC50 values of 1.655 μg/mL. The synthesized compounds were evaluated for their in silico molecular docking analysis using S. aureus gyrase (PDB ID: 2XCT) and human myeloperoxidase (PDB ID: 1DNU) and were found to have minimum binding energy ranging from −7.8 to −10.0 kcal/mol with 2XCT and −7.5 to −9.7 with 1DNU. Compound 11a showed very good binding score −9.7 kcal/mol with both of the proteins and had promising alignment with in vitro results. Compound 11b also showed high binding scores with both proteins. Drug likeness and ADMET of synthesized compounds were predicted. The DFT analysis of synthesized compounds was performed using Gaussian 09 and visualized through Gauss view 6.0. The structural coordinates of the lead compounds were optimized using B3LYP/6–31 G (d,p) level basis set without any symmetrical constraints. Studies revealed that all the synthesized compounds might be candidates for further antibacterial and antioxidant studies.


2021 ◽  
Vol 4 (1) ◽  
pp. 63
Author(s):  
Devi Indah Sari ◽  
Retno Sri Wahjuni ◽  
Ratih Novita Praja ◽  
Budi Utomo ◽  
Faisal Fikri ◽  
...  

The purpose of this study was to determine in vitro inhibition test of lime peel liquid (Citrus aurantifolia, Swingle) against E. coli. The E. coli isolate was cultured on Muller Hinton Agar (MHA) media. Antibacterial test in this study using diffusion method. Negative control (K-) using CMC-Na 0.1%. Positive control (K+) using oxytetracycline antibiotics. The treatments were given lime peel liquid (Citrus aurantifolia, Swingle) with concentrations of 100%, 75%, 50% and 25%, respectively. The study design using Completely Randomized Design (CRD) method, with six treatments and four repetitions. Data were analyzed by Kruskal-Wallis test, Moreover, the Post Hoc Mann-Whitney method. The inhibition zone analysis results were showed that K + had significant differences compared to all treatments K-, 100%, 75%, 50%, and 25%. K- was found to be significantly different from treatments 100%, 75%, 50% and 25%. The results showed that the lime peel liquid has the potential as an antibacterial activity against the growth of E. coli in vitro. Concentration of 25% has shown the presence of inhibitory zones on Mueller Hinton media that have been inoculated with lime peel liquid.


Author(s):  
Negin Karami ◽  
Abolfazl Kamkar ◽  
Yasser Shahbazi ◽  
Ali Misaghi

Various natural oils/extracts and their constituents incorporated into biopolymer-based edible films as a promising technology with the knowledge that these compounds have been able to reduce microbial growth and chemical changes of packed foodstuffs. The objective of this study was to evaluate the effect of incorporation of Ziziphora clinopodioides essential oil (ZEO; 0, 0.25 and 0.5%) and sesame oil (SO; 0, 0.5 and 0.75%) into chitosan-flaxseed mucilage (CH-FM) film against Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus and Escherichia coli O157:H7 in vitro condition and raw minced trout fillets during refrigerated condition. The in vitro antibacterial and antioxidant properties of CH-FM films were evaluated using agar disk diffusion method and free radical scavenging activity assay, respectively. The most important constituents of ZEO were found to be carvacrol (65.22%), thymol (19.51%), ɣ-terpinene (4.63%) and p-cymene (4.86%). The lowest and highest antimicrobial effect against S. aureus, L. monocytogenes, E. coli O157:H7 and S. typhimurium were found for CH-FM films enriched with SO 0.5% (0.98-1.24 mm) and ZEO 0.5% + SO 0.75% (5.01-6.25 mm), respectively. The antioxidant property of CH-FM based films were found to be ranged 5.45% ± 0.04-37% ± 0.45. In treated trout fillets, the counts of L. monocytogenes, S. aureus, E. coli O157:H7 and S. typhimurium were 1.54-4.18, 0.34-3.35, 0.29-1.45 and 0.19-1.27 log CFU/g significantly lower than control groups after two weeks of refrigerated storage, respectively. The designated films had good antibacterial effect against some food borne pathogenic bacteria including L. monocytogenes, S. aureus, S. typhimurium and E. coli O157:H7 in raw rainbow trout fillets.


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.


2019 ◽  
Vol 31 (9) ◽  
pp. 2057-2064
Author(s):  
S.R. Ashok ◽  
M.K. Shivananda ◽  
A. Manikandan

Molecular adaptation of small molecules that are targeted as therapeutic agents is a most anticipated one in drug designing and development. In the present approach, a family of substituted 1H-benzo[d]imidazol-2-amine derivatives (5a-d and 6a-e) were effectively synthesised and testified for their molecular adaptations in order to develop them as novel medications against oxidation, inflammation and inflammation associated cancer types by means of in silico and in vitro assessments. Chronic inflammation, regardless of infectious agents, plays a vital role in various cancer development. Moreover, hypoxia-inflammation-cancer are highly associated together. Hydrogen peroxide free-radical scavenging, HRBC membrane stabilization assay and cell viability test by MTT assay (macrophage) were executed to establish antioxidant, anti-inflammatory and anticancer properties of these compounds. As the prostaglandin-endoperoxide synthase 2 is highly involved in inflammation and cancer development respectively, molecular docking was executed on the corresponding X-ray crystallographic models (PDB structures).


Author(s):  
Sandeep Sandeep ◽  
Abhilasha Mittal ◽  
Abhilasha Mittal

 Objective: The objective of the study was to investigate the pharmacological evaluation of previously isolated compounds (CR-1 to CR-5) from the areal part of Cuscuta reflexa Roxb. is reported.Methods: The antimicrobial and antioxidant activity of the isolated compounds (CR-1 to CR-5) from C. reflexa was determined by the disc-diffusion method and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) model, respectively. The antimicrobial activity was performed against four strains Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa.Results: The results revealed that highest zone of inhibition is measured by compound CR-5 against E. coli. The antioxidant activity is evaluated for in vitro antioxidant activity using DPPH radical scavenging activity, inhibitory concentration 50% (IC50) (120.92–76.38 %), respectively. The results indicate that isolated compound CR-1 and CR-2 having IC50 76.38 and 76.94 μg/ml, respectively, showed potent antioxidant activity comparable to standard ascorbic acid (IC50 43.42 μg/ml).Conclusion: This study suggests that areal part of C. reflexa have bioactive compounds for a new antimicrobial and antioxidant drug development.


2017 ◽  
Vol 8 (2) ◽  
pp. 101-106
Author(s):  
Ruth Elenora Kristanty ◽  
Junie Suriawati ◽  
Priyanto Dwi Nugroho

Honey is a highly nutritious food product and consumed by almost all the population in the world. It has a function as an antimicrobial. Staphylococcus aureus (S. aureus) is a common Gram-positive bacteria in food and Escherichia coli (E. coli) is a Gram-negative bacteria that often appears in environmental sanitation issues that both can cause infectious diseases.  Some infectious diseases can be treated with antimicrobials such as honey. The purpose of this study was to test the antimicrobial effects on honey products distributed in Pasar Minggu area. The antimicrobial effect test was performed in vitro using agar diffusion method by measuring the inhibition zone formed where the bacteria growth was inhibited by the presence of sample. The concentration of samples were 25%, 50%, 75%, and 100% (not diluted) and as aquades control. The results showed that honey tested with various dilution concentrations resulted inhibition zone and. The higher concentration of the inhibited zone zone showed antimicrobial activity against S. aureus and E. coli.


2020 ◽  
Vol 10 (5) ◽  
pp. 274-292
Author(s):  
Rohit Kumar ◽  
Sushil Kumar ◽  
Mohammad Asif Khan

Recently a series of Schiff bases of diphenylamine derivatives have been synthesized and evaluated in vitro for their antibacterial activity against pathogenic both Gram-positive bacteria B. subtitles and Gram-negative bacteria E. coli using ciprofloxacin as standard drug at conc. of 50 μg/ml and 100 μg/ml. Literature review revels that chalcones possesses various biological activities like antimicrobial, antiviral, anti-inflammatory, anticancer and sedative etc. Therefore the present study was designed on synthesis and pharmacological evaluation of 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides. Target compound was synthesized by reaction of chloroacetylchloride with diphenylamine to afford 2-chloro-N, N-diphenylacetamide which further by reaction with substituted Chalcones and characterized following recrystallization and evaluated for anti-microbial potential through cup-diffusion method. In results, the target compounds were tested for activity against B. Subtilis, E.Coli and C. albicans. The chalcones having the lipophilic 4-chloro group (RKCT2) showed the greatest antimicrobial activity (zone of inhibition 20 & 22 mm against. B. subtilis, E. Coli, C. Albicans respectively. It suggests further researchers to go through anti-microbial evaluations against a more varieties of bacteria and fungi. Keywords: Schiff bases of diphenylamine derivatives, antibacterial activity, Gram-positive bacteria, 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides


Author(s):  
AJITH S ◽  
KRISHNA V ◽  
RAVI KUMAR S ◽  
VINAY KUMAR NM

Objective: The present study was designed to evaluate the chemical composition of the essential oil of Buchanania lanzan Spreng extracted from the seeds and to evaluate in vitro antimicrobial antioxidants and molecular docking studies of the major bioactive compounds of essential oil. Methods: The essential oil was obtained by hydrodistillation of the B. lanzan seeds and analyzed by gas chromatography-mass spectrometry (GC-MS). Antibacterial activity was evaluated against Pseudomonas aeruginosa, Salmonella typhi, Vibrio cholerae, Staphylococcus aureus, and Streptococcus pneumoniae clinical isolates by disk diffusion method and resazurin assay determined the minimum inhibitory concentration. The in vitro antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2) scavenging assay; the essential oil major bioactive compounds are Androstan-3-ol, Campesterol, and γ-Sitosterol were docked against bacterial protein DNA gyrase. Results: GC-MS analysis exhibited the presence of 19 bioactive compounds. The essential oil showed that significant antibacterial activity was noticed against V. cholerae and S. typhi with the highest zone of inhibition 15.67–1.20 and 13.83–0.33, respectively. Antioxidant activity in DPPH and H2O2 scavenging assays with IC50 values of 134.23 and 191.24, respectively. The molecular docking of Androstan-3-ol and γ-Sitosterol with bacterial DNA gyrase unveiled a good binding affinity of −6.4 kcal/mol and −6.3 kcal/ mol, respectively. Conclusion: It could be concluded that the essential oils potential sources of antibacterial, antioxidant activities, and molecular docking of bioactive components. The results of this study provide partial scientific support for the traditional application of essential oils to cure diarrhea and also major bioactive compounds responsible for important biological activities.


Sign in / Sign up

Export Citation Format

Share Document