scholarly journals SYNTHESIS, CHARACTERIZATION AND IN VITRO ANTIMICROBIAL EVALUATION OF SOME NOVEL BENZIMIDAZOLE DERIVATIVES BEARING HYDRAZONE MOIETY

Author(s):  
Jayanta Sarma ◽  
Gurvinder Singh ◽  
Mukta Gupta ◽  
Reena Gupta ◽  
Bhupinder Kapoor

Objective: The synthesis of novel benzimidazole-hydrazone derivatives has been carried out based on the previous findings that both these pharmacophores possess potent antimicrobial activities. The antibacterial properties of synthesized derivatives were screened against both Gram-positive and Gram-negative bacteria.Methods: O-phenylenediamine on condensation with substituted aromatic acids in polyphosphoric acid gave benzimidazole nucleus which on reaction with ethyl chloroacetate and hydrazine hydrate in two different steps resulted in the formation of substituted acetohydrazides. The targeted compounds 6a-l were synthesized by reaction of substituted acetohydrazides with aromatic aldehydes and screened for their antibacterial potential by cup-plate method.Results: The synthesized benzimidazole-hydrazones exhibited moderate to strong antibacterial activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The compounds 6a-6f were found to be most effective against S. aureus, E. coli, and P. aeruginosa. Among all the synthesized compounds, the zone of inhibition of 6f in highest concentration, i.e., 100 μg/ml were found to be >31 mm against all the stains of bacteria.Conclusion: The antibacterial results revealed that the synthetized derivatives have significant antimicrobial properties and further structure activity relationship studies may develop more potent and less toxic molecules.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1859
Author(s):  
Periyan Durairaju ◽  
Chinnasamy Umarani ◽  
Govindasami Periyasami ◽  
Perumberkandigai Adikesavan Vivekanand ◽  
Mostafizur Rahaman

Herein we report new multiblock chalcone conjugate phthalimide and naphthalimide functionalized copolymers with a topologically novel architecture synthesis using nucleophilic substitution and polycondensation methodology. The structures of the synthesized novolacs were elucidated on the basis of their spectroscopic analysis including FTIR, 1H NMR, and 13C NMR spectroscopy. Further, the number-average and weight-average molecular weights of the novolac polymers were determined by gel permeation chromatography (GPC). We examined the solubility of the synthesized polymers in various organic solvents including CHCl3, CH3CN, THF, H2O, CH3OH, DMSO, and DMF and found they are insoluble in both methanol and water. The novolac polymers were evaluated for their photophysical properties and microbial activities. The investigation of the antimicrobial activities of these polymers reveals significant antimicrobial activity against the pathogens E. coli, S. aureus, C. albicans, and A. niger.


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.


2020 ◽  
Vol 13 (2) ◽  
pp. 166-180
Author(s):  
Bashige Chiribagula V ◽  
Bakari Amuri S ◽  
Okusa Ndjolo Philippe ◽  
Kahumba Byanga J ◽  
Duez P ◽  
...  

Dialium angolense is used in Bagira for its various medicinal properties particularly in the management of infectious diseases. In this study, the methanol and aqueous extracts of leaves and fruits were evaluated for their in vitro antioxidant and antimicrobial properties and their in vivo toxicity on Cavia porcellus. The major phytochemical classes of extracts were screened using standard in-tube reactions. The antimicrobial study was tested on Candida albicans, Escherichia coli, Salmonella typhi, Staphylococcus aureus and Streptococcus pneumoniae using agar well diffusion and dilution methods, while the antioxidant activity was evaluated by a DPPH assay. For the acute toxicity study, animals (6/group) were orally given in a single dose 5000, 1000 or 15000 mg of extract/kg body weight (BW) then observed for 14 days. In sub-acute toxicity assays, 150 or 300 mg/kg BW/day were orally given, and animals observed for 28 days. Total phenolics and total flavonoids contents ranged 1.19 to 1.61 mg GAE.g-1 and 0.45 to 1.01 mg QEg-1, respectively. The extracts presented antioxidant activity with IC50 ranging 4.9 to 6.9 µg/mL. The minimal inhibitory concentration (MIC) on tested strains ranged from 1.9 to 500 µg/mL with the aqueous extract of fruits as a most active extract: MIC=1.9 µg/mL on E. coli and C. albicans. No signs of toxicity were noted during the acute and sub-acute toxicity assessments, suggesting a maximal tolerate doses (MDT) and LD50 > 15000 mg/kg BW. This study highlights the antioxidant and antimicrobial activities of Dialium angolense and suggests that further studies be directed towards the isolation of active compounds.


2021 ◽  
Vol 6 (3) ◽  
pp. 189-195
Author(s):  
Hary Widjajanti ◽  
Christina Vivid Handayani ◽  
Elisa Nurnawati

The antibiotic resistance of phatogenic bacteria has become a serious health problem and has encouraged the search for novel and effective antimicrobial metabolites. Meanwhile, endophytic fungi have great potential as a natural source for antimicrobial agents. The endophytic fungi that live in plant tissue produces secondary metabolites which potentially act as an antibacterial compound. The isolation of fungi for antibacterial sources reduces the large amount of plant as a source of antibacterial agents. Hence, this study aims to obtain endophytic fungi isolates from Paederia foetida L. that are capable of producing secondary metabolites as antibacterial, carry out in vitro tests to verify the antibacterial properties of secondary metabolites of the Paederia foetida L. endophytic fungi, and identify the potential of Paederia foetida L. endophytic fungi in producing antibacterial compounds. The antibacterial activity was tested against Escherichia coli ATCC8739 and Staphylococcus aureus ATCC6538 while seven isolates of endophytic fungi that potentially produced antibacterial were obtained from Sembukan (P. foetida L.). The results showed that antibacterial activities of SL1, SL4 and SL6 secondary metabolites against S. aureus ATCC6538 and E. coli ATCC8739 were moderate to strong activities. Furthermore, the Minimum Inhibition Concentration (MIC) of secondary metabolites extract of SL1 against S. aureus ATCC6538 value was 250 ????g/mL while the values of MIC extract of SL4 against S. aureus ATCC6538 and E. coli ATCC8739 were 125 ????g/mL and 250 ????g/mL respectively and MIC extract of SL6 against E. coli ATCC8739 value was 125 ????g/mL. The secondary metabolites extract of SL1 isolate were alkaloid and tannin, SL4 were phenolic and alkaloid while SL6 isolate were alkaloid and terpenoid. Hence, endophytic fungi SL1 isolate was identified as Fusarium sp., SL4 as Dematophora sp., and SL6 isolate as Acremonium sp.


2018 ◽  
Vol 16 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Wilfred O Obonga ◽  
Philip F Uzor ◽  
Emmanuel O Ekwealor ◽  
Sampson C Nwabuko

The present study was aimed at a comparative study of the phytoconstituents, antioxidant and antimicrobial properties of four medicinal plants, Ficus capensis, Aristolochia ringens, Albizia zygia and Lannea welwitschii. The leaf of F. capensis and stem bark of A. ringens, A. zygia and L. welwitschii were extracted using methanol. Phytochemical analysis was done spectrophotometrically. Three in vitro antioxidant tests-hydrogen peroxide (H2O2), nitric oxide (NO) and 2, 2-diphenyl-1-picrylhydroxyl (DPPH) scavenging models were employed. Antimicrobial test was done by agar diffusion method against E. coli, Staphylococcus aureus, Klebsiela pneumonia, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Candida albicans and Aspergittus spp. Phytochemical analysis revealed that the most abundant phytoconstituents were flavonoids (F. capensis and A. zygia), reducing sugar, terpenoids, alkaloids and tannins. In the antioxidant models, A. zygia was found to produce the least IC50 in two of the models (NO and DPPH). Results of the antimicrobial tests showed that A. zygia showed a broader spectrum of activity than other plants. This study has shown that these plants possess antioxidant and antimicrobial activities which further justify their usage in traditional medicines. A. zygia featured prominently in these activities. Also flavonoids could be responsible for the bioactivities of these plants.Dhaka Univ. J. Pharm. Sci. 16(2): 147-157, 2017 (December)


2019 ◽  
Vol 31 (9) ◽  
pp. 2015-2021
Author(s):  
Ashok K. Singh ◽  
Suresh K. Patel ◽  
Asif Jafri

A series of eight Co(III) complexes [CoL1-8(H2O)2Cl] (I-1 to I-8) incorporating 4-(2-substituted phenylimino)-2-(4-substituted phenyl)-4H-chromen-3-ol, as a tridentate imino flavone ligands (L1 to L8, 2-sub. = NH2, SH, 4-sub. = OMe, OH, Cl, NMe2) have been synthesized, characterized and the geometry of the complexes were optimized by DFT. The chemical structure of synthesized imino flavone ligands and their complexes were characterized by elemental analysis, 1H NMR, 13C NMR, UV-visible, IR, ESI-mass spectral data, conductometric and magnetic measurements. The synthesized compounds have been screened for their in vitro antibacterial activities against bacteria Vibrio cholerae, Salmonella typhi, Staphylococcus aureus, Escherichia coli and antifungal activities against fungi Candida albicans and Aspergillus flavus by paper disc diffusion method. The complexes I-3, I-4, I-7 and I-8 showed good antimicrobial activities against pathogens.


2020 ◽  
Vol 83 (2) ◽  
pp. 331-337
Author(s):  
WENYUE WANG ◽  
RUI WANG ◽  
GUIJU ZHANG ◽  
FANGLI CHEN ◽  
BAOCAI XU

ABSTRACT Naturally occurring monoglyceride esters of fatty acids have been associated with a broad spectrum of antimicrobial activities. We used an automated turbidimetric method to measure the MIC and assess the antimicrobial activity of five monoglycerides (monocaprin, monolaurin, monomyristin, monopalmitin, and monostearin) against pathogenic strains of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. The antibacterial activity of monocaprin was highest because its carbon chain is shorter than those of other monoglycerides. The MICs of monocaprin against S. aureus, B. subtilis, P. aeruginosa, and E. coli were 0.32, 0.32, 2.5, and 2.5 mg/mL, respectively. Monocaprin had antibacterial activity under neutral and alkaline conditions (pH 7.0 to 9.0) but had no inhibitory effect on S. aureus, B. subtilis, and E. coli under weakly acidic conditions (pH 6.0). The antibacterial mechanism of monocaprin against gram-positive strains (S. aureus and B. subtilis) resulted from destruction of the cell membrane. In contrast, the antibacterial activity of monocaprin against gram-negative strains (P. aeruginosa and E. coli) was attributed to damage to lipopolysaccharides in the cell walls. Because of its inhibitory effect on both gram-positive and gram-negative bacteria, monocaprin could be used as an antibacterial additive in the food industry. HIGHLIGHTS


2021 ◽  
Vol 17 (7) ◽  
pp. 1435-1447
Author(s):  
Quan-Ming Zhao ◽  
Bo Li ◽  
Fu-Xun Yu ◽  
Yan-Kun Li ◽  
Jie-Shi Wu ◽  
...  

Titanium (Ti) and its alloys are widely used in bone surgery by virtue of their excellent mechanical properties and good biocompatibility; however, complications such as loosening and sinking have been reported post-implantation. Herein we deposited a copper–cobalt (Cu–Co) co-doped titanium dioxide (TUO) coating on the surface of Ti implants by microarc oxidation. The osteogenic and antimicrobial properties of the coating were evaluated by in vitro experiments, and we also assessed β-catenin expression levels on different sample surfaces. Our results revealed that the coating promoted the adhesion, proliferation, and differentiation of MG63 osteoblasts, and TUO coating promoted β-catenin expression; moreover, the proliferation of Staphylococcus aureus was inhibited. To summarize, we report that Cu–Co co-doping can enhance the osteogenic and antibacterial activities of orthopedic Ti implants, leading to potentially improved clinical performance.


Author(s):  
Anjani Solankee ◽  
Riki Tailor

In our present investigation a new class of diverse sets of acetyl pyrazolines (6a-e), amino pyrimidines (7a-e) and 1,5-benzodiazepines (8a-e) bearing 1,3,5-triazine core were synthesised from chalcones (5a-e). Treatment of chalcone with hydrazine hydrate, guanidine hydrochloride and o-phenylenediamine afforded the corresponding acetyl pyrazoline, amino pyrimidine and 1,5-benzodiazepine derivatives respectively. The structures of all the newly synthesised compounds were assigned on the basis of FTIR, 1H NMR, 13C NMR, mass spectral data as well as elemental analysis. In vitro antimicrobial proficiency of the title compounds were assessed against selected pathogens S. aureus MTCC 96, S. pyogeneus MTCC 442, E. coli MTCC 443 and P. aeruginosa MTCC 1688 bacteria for antibacterial activities as well as antifungal activities against C. albicans MTCC 227, A. niger MTCC 282 and A. clavatus MTCC 1323 were used. The minimum inhibitory concentration (MIC) was determined by broth dilution method and recorded at the lowest concentration inhibiting growth of the organism. Among the synthesised compounds 6b, 6c, 7b, 8b, 8d and 8e exhibited excellent antimicrobial activity and said to be the most proficient members of the series.


2020 ◽  
Vol 3 (1) ◽  
pp. 71
Author(s):  
Asmaâ Sameut ◽  
Sarah Yasmine Zanndouche ◽  
Chaimaa Boumaza ◽  
Chaima Dikes ◽  
Borhane Eddine Cherif Ziani

Benzimidazole derivatives represent a class of heterocyclic compounds that exhibit a wide range of pharmaceutical properties. The present study aimed to investigate the in-vitro antioxidant and antimicrobial activities of newly synthesized benzimidazole derivatives. Compound 1b (2-(1H-1,3-benzodiazol-2-yl) phenol) was synthesized by reacting o-phenylenediamine (OPA) with chemical salicylaldehyde, while compounds 2b (2-(2-[(1E)-2-phenylethenyl]-1H-1,3-benzodiazole) and 3b (2-[(1E)-2,6-dimethylhepta-1,5-dien-1-yl]-1H-1,3-benzodiazole) were obtained through a hemi-synthesis process of, respectively, the cinnamon (cinnamaldehyde, 90.54%) and lemongrass (cis-citral, 43.9%) essential oils previously characterized by GC/MS. Compounds 4b (2-phenyl-1H-benzimidazole) and 5b (5-(1H-benzimidazol-2-yl)benzene-1,2,3-triol) were synthesized with a click chemistry method by reacting the OPA with benzoic acid and gallic acid directly in ethanol under microwave irradiation (MW) at 400 MHz. The structure/purity of the synthesized compounds was clarified by spectroscopy, ATR-FTIR and NMR 1H. Compounds 1b–5b were screened for their antioxidant activity by using four complementary in-vitro assays: DPPH scavenging activity, ferric ion reducing power, β-carotene bleaching inhibition, and Thiobarbituric Acid Reactive Substance Assay (TBARS) formation inhibition. All the tested compounds showed antioxidant potential, with varying performance. Antimicrobial activity was investigated against American Type Culture Collection (ATCC) strains (three Gram- bacteria: Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa; one Gram+ bacteria: Staphylococcus aureus, and one yeast strain: Candida albicans) through the determination of the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) by using the microdilution method and rapid colorimetric test of p-iodonitrotetrazolium chloride (INT). Compound 5b exhibited the highest potential, especially against S. aureus (MIC = 0.156 mg·mL−1) followed by S. typhi and C. albicans (MIC = 0.3125 mg·mL−1) and then by E. coli and P. aeruginosa. Compound 1b also showed great potential against S. aureus and C. albicans (MIC ˂ 0.3125 mg·mL−1), followed by E. coli and S. typhi (MIC = 0.3125 mg·mL−1) and P. aeruginosa (MIC = 0.625 mg·mL−1). Further molecular docking was conducted using AutoDock Vina 1.1.2 software on S. aureus thymidylate kinase (TMK) protein to highlight the structure–activity relationship of the potent molecules.


Sign in / Sign up

Export Citation Format

Share Document