scholarly journals Copper(II) complexes of substituted salicylaldimines with benzimidazole nucleus: synthesis, characterization and antimicrobial activity

Author(s):  
Abdullahi Sobola ◽  
Gary Watkins

The aim of this study was to synthesize and evaluate the antimicrobial activity of Cu(II) complexes of some substituted salicylaldimines with benzimidazole nucleus. The salicylaldimine ligands were prepared by condensing 2-aminobenzimidazole with salicylaldehyde, o-vanillin and p-vanillin. All the compounds and the Cu(II) complexes were characterized by elemental , electronic, infrared and molar conductivity data. In addition, the structures of the ligands were confirmed with 1H-NMR and 13C-NMR spectral data. Both the ligands and the Cu(II) complexes have been screened for their in vitro antimicrobial activity against Staphylococcus aureus subsp. aureus ATCC® 6538™, Bacillus substillis subsp. spizizenii ATCC® 6633™*, Escherichia coli ATCC® 8739™* and Candida albicans ATCC® 2091™* using agar diffusion and broth dilution techniques. The ligands coordinated to the Cu(II) ion in a 1:2 (M:L) ratio as tridentate monobasic species via the imine-N, the imidazole-N and the phenolic–O to give six-coordinated Cu(II) complexes. The free ligands exhibited varying antimicrobial activity on the tested organisms from low activity to significant potency. Candida albicans was specifically susceptible to the o-vanillin Schiff base ligand. The presence of Cu(II) ion, however, did not have a regular effect on the activity of the compounds.

2020 ◽  
Vol 151 ◽  
pp. 15550-15558
Author(s):  
Amégninou Agban ◽  
Yao Hoekou ◽  
Passimna Pissang ◽  
Tchadjobo Tchacondo ◽  
Komlan Batawila

Objectif : L’objectif de ce travail était d’évaluer in vitro l’activité antimicrobienne des extraits de feuilles et tige de Jatropha multifida sur la croissance de Candida albicans, Escherichia coli et Staphylococcus aureus, puis d’évaluer in vivo la toxicité de cette plante. Méthodologie et résultats : Les méthodes de diffusion en milieu gélosé et de microdilution en milieu liquide ont été utilisées pour évaluer l’effet antimicrobien. Une étude en subaigüe était réalisée afin d’explorer les effets toxiques de l’extrait aqueux des feuilles. Les résultats des tests antimicrobiens montrent une activité des extraits de feuilles et tige de J. multifida sur la croissance des souches utilisées avec des diamètres de zones d’inhibition allant de 8 à 25 mm et des concentrations minimales inhibitrices (CMI) variant de 0,039 mg/mL à 1,25 mg/mL à l’exception des souches de E. coli qui sont résistantes aux extraits de la tige. L’administration en subaigüe de l’extrait aqueux des feuilles de J. multifida à la dose de 600 mg/kg entraîne une perte significative de poids chez les souris. Conclusion et applications des résultats : Les extraits aqueux, éthanolique et hydroéthanolique des feuilles et tige de J. multifida possèdent d’activité antimicrobienne et pourraient être utilisés dans le traitement des Candidoses à C. albicans et des infections à S. aureus. Mais l’essai de toxicité subaigüe montre que l’extrait aqueux de la plante serait toxique. Des études toxicologiques approfondies restent donc nécessaires sur ces extraits afin de mieux élucider leur inocuité. Mots-clés : Jatropha multifida, extraits de feuilles et de tige, activités antifongique et antibactérienne, toxicité. Agban et al., J. Appl. Biosci. 2020 Evaluation du potentiel antimicrobien et de la toxicité des extraits de Jatropha multifida Linn, (Euphorbiaceae) 15551 Evaluation of antimicrobial potential and toxicity of Jatropha multifida Linn, (Euphorbiaceae) extracts ABSTRACT Objective: The objective of this study was to evaluate in vitro the antimicrobial activity of leaves and stem of Jatropha multifida extracts against Candida albicans, Escherichia coli and Staphylococcus aureus, and then to evaluate in vivo the toxicity of this plant. Methodology and Results: The agar well-diffusion and the NCCLS broth microdilution methods were used to assess the antimicrobial effect. A subacute study was carried out to explore the toxic effects of the aqueous extract of the leaves. The results of the antimicrobial tests show an activity of the extracts of leaves and stems of J. multifida on the growth of the strains used with diameters of inhibitory zones ranging from 8 to 25 mm and minimum inhibitory concentrations (MIC) varying from 0.039 mg/mL to 1.25 mg/mL exception E. coli strains which are resistant to extracts from the stem. Subacute administration of the aqueous extract of the leaves of J. multifida at a dose of 600 mg/kg leads to a significant loss of weight in the mice. Conclusion and application of findings : The aqueous, ethanolic and hydroethanolic extracts of the leaves and stem of J. multifida have antimicrobial activity and could be used in the treatment of Candidiasis and bacterial infections due respectively to C. albicans and S. aureus. But the subacute toxicity test shows that the aqueous extract of the plant would be toxic. Extensive toxicological studies therefore remain necessary on these extracts in order to better elucidate their safety. Keywords: Jatropha multifida extracts of leaves and stem, antifungal and antibacterial activities, toxicity


Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1158
Author(s):  
Abdelsamed I. Elshamy ◽  
Tarik A. Mohamed ◽  
Eman M. Elkady ◽  
Ibrahim A. Saleh ◽  
Ahmed A. El-Beih ◽  
...  

The organic extracts of the Red Sea soft coral Paralemnalia thyrsoides has led to the identification of two neolemnane-type sesquiterpenoids: paralemnolins X and Y (1, 2). In addition to these newly characterized compounds, ten known metabolites (3–12) were isolated. Previously reported compounds were elucidated by literature comparison of spectroscopic data (1D and 2D NMR as well as MS data). In vitro antimicrobial activity was investigated for compounds (1–12) against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. Compound 5 showed antimicrobial activity against all assayed microorganisms.


2021 ◽  
Vol 14 (03) ◽  
pp. 249-253
Author(s):  
Nicholas Chinedu Ewelike ◽  
Joy Chinyere Okammadu ◽  
Vincent Ezechukwu Ogwudire ◽  
Raymond Ikechukwu Nnadozie

Methanolic and aqueous leaf extracts of Chrysophyllum albidum (African star apple) and Garcinia kola (bitter kola) were studied for in-vitro microbial activity using the disc diffusion technique. The aqueous and methanolic leaf extracts of Chrysophyllum albidum showed antimicrobial activity against Escherichia coli, Staphylococcus aureus and Candida albicans but showed no antibacterial activity against Klebsiella pneumonia. The methanolic leaf extract of Garcinia kola inhibited the growth of Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia while the aqueous extract of the leaf inhibited the growth of Staphylococcus aureus and Escherichia coli. Both methanolic and aqueous leaf extracts of the plant showed no antifungal activity against Candida albicans. The minimum inhibitory concentrations of the leaf extracts of Chrysophyllum albidum ranged from 12.5 mgL-1 to 25 mgL-1 while those of Garcinia kola ranged from 25 mgL-1 to 50 mgL-1. The results obtained suggest that the leaves of these plants can be used in treating diseases caused by the test organisms. The further investigation on the crude extracts would characterize bioactive components of the leaves of Chrysophyllum albidum and Garcinia kola.


2018 ◽  
Vol 42 (6) ◽  
pp. 332-336 ◽  
Author(s):  
Sayed K. Ramadan ◽  
Eman A. E. El-Helw

6-Chloro-3-((2-oxo-5-phenylfuran-3(2 H)-ylidene)methyl)-4 H-chromen-4-one was utilised for the construction of N-heterocycles. The proclivity of this furanone towards some nitrogen nucleophiles, i.e. glycine, thiosemicarbazide, thiocarbohydrazide, phenylhydrazine and o-phenylenediamine, was studied. The structures of all products obtained were established on the basis of their analytical and spectral data. All synthesised compounds were screened for their in vitro antibacterial (two strains of bacteria; Escherichia coli and Staphylococcus aureus) and antifungal (two fungus strains; Aspergillus flavus and Candida albicans) activities. Some products exhibited promising antimicrobial activities.


2019 ◽  
Vol 32 (1) ◽  
pp. 192-194
Author(s):  
S. Sudha Kumari

In present work, the screening of antimicrobial activities of copper(II) and cobalt(II) complexes with Schiff base ligand derived from the condensation of citral with valine (amino acid) was carried out on agar plates are reported. The antibacterial activity of Schiff base and its copper(II) and cobalt(II) complexes were evaluated against two bacterial strains Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative) and fungus Candida albicans. The results revealed that the Schiff base ligand exhibited the poor antimicrobial activity against Escherichia coli and Candida albicans except for Staphylococcus aureus. Generally, Gram-negative bacteria shows rigid outer membrane, well enough to defend against the drug but Schiff base (citral with valine derived) impregnated cobalt(II) complex seem to be more active against Escherichia coli organisms in comparison to copper(II) complex, which exhibits higher activity than uncomplexed ligand. The antimicrobial results revealed that cobalt(II) and copper(II) complexes have a considerable antibacterial activity than antifungal activity and suggest their potential application as antibacterial agents.


2012 ◽  
Vol 518-523 ◽  
pp. 255-260 ◽  
Author(s):  
Xiao Yang Qiu ◽  
Su Zhi Li ◽  
An Ran Shi

A series of nitrochalcones (compounds 1-10) were synthesized by reacting appropriate nitroacetophenones and suitable benzaldehydes. The synthesized products were evaluated for their cytotoxic, antibacterial (Bacillus subtilis, Escherichia coli, Pseudomonas fluorescence and Staphylococcus aureus) and antifungal (Aspergillus niger, Candida albicans and Trichophyton rubrum) activities in vitro. Among the compounds tested, (E)-3-(4-fluorophenyl)-1-(3-nitrophenyl)- prop-2-en-1-one (10) showed the favorable in vitro cytotoxic activity against human nasopharyngeal epidermoid tumor cell line KB, and (E)-3-(2-methoxyphenyl)-1-(3-nitrophenyl)prop-2-en-1-one (8) showed the strongest antimicrobial activity with MIC of 20 μg/mL against P. fluorescence.


2016 ◽  
Vol 1 (01) ◽  
Author(s):  
Vemavarapu Bhaskara Rao ◽  
Kandlagunta Guru Prasad ◽  
Krishna Naragani ◽  
Vijayalakshmi Muvva

The air dried rhizosphere soil samples pretreated with calcium carbonate was employed for the isolation of actinomycete strains. Serial dilution plate technique was used for the isolation of actinomycetes. A total of 20 actinomycete strains designated as BS1-BS20 were isolated from the rhizosphere of medicinal plant Clitoria ternatea. All the 20 strains were subjected to primary screening for antimicrobial activity. Among the 20 strains screened, 10 strains exhibited high antimicrobial spectrum against Staphylococcus aureus, Escherichia coli and Candida albicans.


2019 ◽  
Vol 18 (5) ◽  
pp. 262-274
Author(s):  
E. Benyagoub ◽  
N. Nabbou ◽  
S. Boukhalkhel ◽  
I. Dehini

The medicinal value of the plants is due to their chemical components that bring a definite physiological action on the human body to prevent the diseases. In this work, we investigated the antimicrobial activity of leaves’ extracts of Quercus robur L., collected from the Algerian upper highlands, on ten bacterial strains and one fungal strain known to be pathogenic. First, we performed a qualitative phytochemical analysis, and second, antimicrobial activity tests performed by agar diffusion method (disc and well) with the determination of MIC by broth macro-dilution method. Given the results, it appears that obtained macerates of Quercus robur L. were rich in bioactive phytoconstituents such as alkaloids, anthraquinones, saponins, tannins, and other components. The yield of aqueous and methanolic macerates of leaves was 8.5 ± 1.41 and 22.4 ± 4.36%, respectively. The bacterial resistance was relatively important to several antibiotics, namely, ampicillin, amoxicillin + clavulanic acid for strains of Escherichia coli and Salmonella sp. However, Staphylococcus aureus strains were resistant to fusidic acid, penicillin, and oxacillin; while Enterococcus faecalis was resistant to fusidic acid, penicillin, oxacillin, and ticarcillin. The antibacterial activity of the macerates toward tested microbial strains showed that the aqueous and methanolic macerates of the leaves were proportional to the tested concentration and active not only against Gram-positive and Gram-negative bacteria but also on the fungal species Candida albicans. The estimated MIC for Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus was in the order of 10 mg/mL, which seems more effective than toward Salmonella sp., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans which were in the order of 30 mg/mL. These preliminary results confirm that the part of the studied plant had a very good antimicrobial activity that was proportional to the serial concentrations of the tested extracts.


2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).


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