Synthesis and antibacterial activity of new chalcones bearing an imidazo[1,2-a]pyridine moiety

2021 ◽  
Vol 15 ◽  
Author(s):  
Siavash Salek Soltani ◽  
S. Morteza F. Farnia ◽  
Alireza Foroumadi

Aim and Objective: Herein, A series of new imidazo[1,2-a]pyridine-chalcone derivatives 3a-m were designed and synthesized to find new class of antibacterial agents. These compounds were prepared by the aldol condensation of 2-phenylimidazo[1,2-a]pyridine-3-carbaldehyde 2a-b with acetophenone derivatives and other aromatic acetyls. High reaction yields have been obtained in a short reaction time, through applying this multi-step pathway. Materials and Methods: In vitro antibacterial activities of the synthesized imidazo[1,2-a]pyridine-chalcones were measured against S. aureus, B. subtilis and E. coli with MIC values of 32 -128 μg/mL. Finally, essential structural analyses such as CHN and NMR spectroscopies were used to identify the synthesized chalcones based on imidazo[1,2-a]pyridine derivatives. Results: The results showed that most of the products presented moderate to good antibacterial activities. Compounds 3b, 3d, 3g, 3l and 3m revealed obvious potency against S. aureus, B. subtilis and E. coli with MIC values of 32 μg/mL and 64 μg/mL, which were better when compared with other chalcones. Conclusion: The synthesized antibacterial compounds were obtained with appealing advantages such as high purity, simple pathway, good to excellent yields, inexpensive and easy availability of materials as well as good activities against bacteria. So in this work, new class of antibacterial chalcones based on imidazo[1,2-a]pyridine have been reported.

Author(s):  
Bambang Wijianto ◽  
RITMALENI . ◽  
HARI PURNOMO ◽  
ARIEF NURROCHMAD

Objective: The objective of this research was to design a new analogue compound, hexagamavunon (HGV). Methods: New design of analogue compound, HGV, was performed by QSAR study using BuildQSAR program. In this QSAR study, parameterized model (PM3) method using the Polak-Ribière algorithm was applied to calculate the optimal geometric structures of the used compounds. The new analogue compound, HGV had been synthesized using aldol condensation reaction. The assay of antibacterial activities was performed using the dilution method. Molecular operating environment (MOE) program was used for protocol docking. Results: The results of QSAR study reveal the good relationship of antibacterial activities. The in vitro antibacterial activities of 2,6-bis((E)-3,5-dibromo-4-hydroxybenzylidene) cyclohexan-1-one (A113) indicates the good potential to against S. aureus, B. subtilis and E. coli with IC50 27.3 μg/ml, 30.9 μg/ml, 32 μg/ml respectively. This is in accordance with the in silico evaluation showing that 2,6-bis((E)-3,5-dibromo-4-hydroxybenzylidene) cyclohexan-1-one has lower docking score than both amoxicillin and cefoxitin do as the native ligand of receptor 3MZE. Conclusion: Based on in silico and in vitro assay, 2,6-bis((E)-3,5-dibromo-4-hydroxybenzylidene) cyclohexan-1-one (A113) has good antibacterial activities against S. aureus, B. subtilis, and E. coli.


2021 ◽  
Vol 22 (10) ◽  
Author(s):  
Muhammad Evy Prastiyanto

Abstract. Prastiyanto ME. 2021. Seeds extract of three Artocarpus species: Their in-vitro antibacterial activities against multidrug-resistant (MDR) Escherichia coli isolates from urinary tract infections (UTIs). Biodiversitas 22: 4362-4368. Multidrug-resistant (MDR)-E. coli is a major cause and has become a very serious problem in urinary tract infections (UTIs). As a result, it requires an antibacterial agent derived from biological materials. It has been reported that the seeds of three species of Artocarpus (A. heterophyllous, A. champeden, and A. camansi) have antibacterial properties against Methicillin-Resistant Staphylococcus aureus (MRSA). However, there are three other Artocarpus species in Indonesia, i.e., keledang (A. lanceipolius), tarra (A. elasticus), and terap (A. Odoratissimus) whose antibacterial property has not been investigated. To minimize the research gap, this study aims to determine the antibacterial activity of seed extracts of A. lanceipolius, A. elasticus, and A. odoratissimus against MDR-E. coli isolates of UTIs. Antibacterial activity was evaluated using the agar well diffusion assay. The microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. The results revealed that the seed extracts of A. lanceipolius, A. elasticus, and A. odoratissimus have the potential as antibacterial agents against MDR-E. coli isolate of UTIs. A. elasticus seed extract shows the widest zone of inhibition in the range of 7.0-13.3 mm and the smallest MIC and MBC values ??of 6.25-12.5 mg/mL and 12.5-25 mg/mL, respectively. In conclusion, A. lanceipolius, A. elasticus, and A. odoratissimus seed extracts have the potential to be developed as antibacterial agents against UTI-causing MDR-E. coli. Further in vivo research and determining the mode of action of antibacterial activity are needed.


2020 ◽  
Vol 17 (5) ◽  
pp. 716-724
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  

Background: The key issue in the development of novel antimicrobials is a rapid expansion of new bacterial strains resistant to current antibiotics. Indeed, World Health Organization has reported that bacteria commonly causing infections in hospitals and in the community, e.g. E. Coli, K. pneumoniae and S. aureus, have high resistance vs the last generations of cephalosporins, carbapenems and fluoroquinolones. During the past decades, only few successful efforts to develop and launch new antibacterial medications have been performed. This study aims to identify new class of antibacterial agents using novel high-throughput screening technique. Methods: We have designed library containing 125K compounds not similar in structure (Tanimoto coeff.< 0.7) to that published previously as antibiotics. The HTS platform based on double reporter system pDualrep2 was used to distinguish between molecules able to block translational machinery or induce SOS-response in a model E. coli system. MICs for most active chemicals in LB and M9 medium were determined using broth microdilution assay. Results: In an attempt to discover novel classes of antibacterials, we performed HTS of a large-scale small molecule library using our unique screening platform. This approach permitted us to quickly and robustly evaluate a lot of compounds as well as to determine the mechanism of action in the case of compounds being either translational machinery inhibitors or DNA-damaging agents/replication blockers. HTS has resulted in several new structural classes of molecules exhibiting an attractive antibacterial activity. Herein, we report as promising antibacterials. Two most active compounds from this series showed MIC value of 1.2 (5) and 1.8 μg/mL (6) and good selectivity index. Compound 6 caused RFP induction and low SOS response. In vitro luciferase assay has revealed that it is able to slightly inhibit protein biosynthesis. Compound 5 was tested on several archival strains and exhibited slight activity against gram-negative bacteria and outstanding activity against S. aureus. The key structural requirements for antibacterial potency were also explored. We found, that the unsubstituted carboxylic group is crucial for antibacterial activity as well as the presence of bulky hydrophobic substituents at phenyl fragment. Conclusion: The obtained results provide a solid background for further characterization of the 5'- (carbonylamino)-2,3'-bithiophene-4'-carboxylate derivatives discussed herein as new class of antibacterials and their optimization campaign.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1773
Author(s):  
Patchima Sithisarn ◽  
Piyanuch Rojsanga ◽  
Pongtip Sithisarn

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.


2020 ◽  
Vol 6 (1) ◽  
pp. 10-22
Author(s):  
Zakaria Tabia ◽  
Sihame Akhtach ◽  
Khalil El Mabrouk ◽  
Meriame Bricha ◽  
Khalid Nouneh ◽  
...  

AbstractMultifunctionality can be achieved for bioactive glasses by endowing them with multiple other properties along with bioactivity. One way to address this topic is by doping these glasses with therapeutic metallic ions. In this work, we put under investigation a series of bioactive glasses doped with tantalum. We aim to study the effect of tantalum, on the structure, bioactivity and antibacterial property of a ternary bioactive glass composition based on SiO2-CaO-P2O5. Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Electron Scanning Microscopy (SEM) were used to assess the structural and morphological properties of these glasses and monitor their changes after in vitro acellular bioactivity test. Antibacterial activity was tested against gram positive and negative bacteria. Characterization results confirmed the presence of calcium carbonate crystallites along with the amorphous silica matrix. The assessment of bioactivity in SBF indicated that all compositions showed a fast bioactive response after only six hours of immersion period. However, analytical characterization revealed that tantalum introduced a slight latency in hydroxyapatite deposition at higher concentrations (0.8-1 %mol). Antibacterial test showed that tantalum ions had an inhibition effect on the growth of E. coli and S. aureus. This effect was more pronounced in compositions where mol% of tantalum is superior to 0.4%. These results proved that tantalum could be used, in intermediate proportions, as a promising multifunctional dopant element in bioactive glasses for bone regeneration applications.


Author(s):  
Zohor Mohammad Mahdi Alzhrani ◽  
Mohammad Mahboob Alam ◽  
Syed Nazreen

Background: The frequent uses of antimicrobial agents to treat infections in diabetic patients make them more drug resistance than non diabetic patients which accounts for higher mortality rate of diabetic patients. Therefore, it is a necessity today to synthesize new drugs with dual mode of action as antidiabetic and antibacterial agents. In the present work, new derivatives containing thiazolidinedione and 1,3,4-oxadiaozle have been synthesized and screened for PPAR-γ and antibacterial activities. Methods: Compound 5-12 have been synthesized from 2-methoxy benzaldehyde and thiazolidinedione and characterized using different spectroscopic techniques such as IR, NMR and mass spectrometry. These compounds were tested for in vitro PPAR-γ transactivation, PPAR-γ gene expression and antibacterial activities. Finally molecular docking was carried out to see the binding interactions of molecules with the target protein. Results: All the compounds follow Lipinski rule suggesting the synthesized derivatives have good drug likeness properties. Compound 11 and 12 exhibited promising PPAR-γ transactivation with 73.69% and 76.50%, respectively as well as showed significant antibacterial activity with comparable MIC of 3.12 μg/disc to standard drug amoxicillin. The docking result was found to be in consistent with the in vitro PPAR-γ transactivation results. Conclusion: Compounds 11 and 12 can be further investigated as lead molecules for the development of new and effective antidiabetic and antibacterial agents.


2020 ◽  
Vol 16 (1) ◽  
pp. 104-118 ◽  
Author(s):  
Shi-Chao He ◽  
Hui-Zhen Zhang ◽  
Hai-Juan Zhang ◽  
Qing Sun ◽  
Cheng-He Zhou

Objective: Due to the incidence of resistance, a series of sulfonamide-derived 1,2,4- triazoles were synthesized and evaluated. Method: The novel sulfonamide-derived 1,2,4-triazoles were prepared starting from commercial acetaniline and chlorosulfonic acid by sulfonylation, aminolysis, N-alkylation and so on. The antimicrobial activity of the synthesized compounds were evaluated in vitro by two-fold serial dilution technique. Results: In vitro antimicrobial evaluation found that 2-chlorobenzyl sulfonamide 1,2,4-triazole 7c exhibited excellent antibacterial activities against MRSA, B. subtilis, B. typhi and E. coli with MIC values of 0.02−0.16 μmol/mL, which were comparable or even better than Chloromycin. The preliminary mechanism suggested that compound 7c could effectively bind with DNA, and also it could bind with human microsomal heme through hydrogen bonds in molecular docking. Computational chemical studies were performed on compound 7c to understand the structural features that are essential for activity. Additionally, compound 7c could generate a small amount of reactive oxygen species (ROS). Conclusion: Compound 7c could serve as a potential clinical antimicrobial candidate.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1772
Author(s):  
Hui Lu ◽  
Xia Zhou ◽  
Lei Wang ◽  
Linhong Jin

A series of new N-phenylacetamide derivatives containing 4-arylthiazole moieties was designed and synthesized by introducing the thiazole moiety into the amide scaffold. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR and HRMS. Their in vitro antibacterial activities were evaluated against three kinds of bacteria—Xanthomonas oryzae pv. Oryzae (Xoo), Xanthomonas axonopodis pv. Citri (Xac) and X.oryzae pv. oryzicola (Xoc)—showing promising results. The minimum 50% effective concentration (EC50) value of N-(4-((4-(4-fluoro-phenyl)thiazol-2-yl)amino)phenyl)acetamide (A1) is 156.7 µM, which is superior to bismerthiazol (230.5 µM) and thiodiazole copper (545.2 µM). A scanning electron microscopy (SEM) investigation has confirmed that compound A1 could cause cell membrane rupture of Xoo. In addition, the nematicidal activity of the compounds against Meloidogyne incognita (M. incognita) was also tested, and compound A23 displayed excellent nematicidal activity, with mortality of 100% and 53.2% at 500 μg/mL and 100 μg/mL after 24 h of treatment, respectively. The preliminary structure-activity relationship (SAR) studies of these compounds are also briefly described. These results demonstrated that phenylacetamide derivatives may be considered as potential leads in the design of antibacterial agents.


2020 ◽  
Vol 14 (6) ◽  
pp. 147-155
Author(s):  
J. N. Agbom ◽  
O. Ogbu ◽  
I. R. Iroha ◽  
I. B. Moses ◽  
A. L. Onuora ◽  
...  

2019 ◽  
Vol 4 (4) ◽  
pp. 209-215
Author(s):  
D. Joshi ◽  
R. Narigara ◽  
G. Jani ◽  
K. Parikh

A new class of fluorobenzimidazole derivatives (IIIa-j)was synthesized to investigate their antimicrobial potential. All the compounds were prepared by multiple step synthesis, initiating from the synthesis of 5-(difluoromethoxy)-1H-benzimidazole-2-thiol (I). The compound I was further reacted with different derivatives of 2-chloro-N-phenylacetamide (IIa-j) prepared by reacting differently substituted anilines with chloroacetylchloride and triethylamine in DMF (solvent); resulting in formation of fluorobenzimidazoles IIIa-j. The compounds IIIa-j were characterized by spectral analysis viz. 1H NMR, 13C NMR, mass spectra, elemental analysis and IR. All these compounds were screened in vitro for their antimicrobial activity against Gram-positive (S. aureus and E. faecalis) and Gram-negative bacterial (E. coli and P.aeruginosa) strains as well as fungi (A. niger and C. albicans). Some of the compounds exhibited promising results (in MIC) against Gram-negative bacterial strains.


Sign in / Sign up

Export Citation Format

Share Document