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Benzimidazole and imidazopyridine heterocycles associated with Micha?l acceptors have shown strong anticandidosic potential in our previous work. After a decade of research, we have designed, synthesized and evaluated the anticandidosic activities of seve

With the aim of exploring new benzimidazole derivative with high fungicidal activity, a series of novel 2-(2-(alkylthio)-6-phenylpyrimidin-4-yl)-1H-benzimidazoles were designed and synthesized, and their in vitro fungicidal activities were evaluated. Compounds 5a, 5f, 5g, 5h, 5i and 5l exhibited excellent fungicidal activities against Botrytis cinerea, and 5c, 5f, 5h, 5i and 5l displayed notable fungicidal activities against Sclerotinia sclerotiorum. Among them, compound 5i (R1 = fluorine, R2 = benzyl) displayed the best activity towards the two tested fungi. Docking study of 5i with β-tubulin protein revealed that the NH moiety of benzimidazole ring generated a hydrogen bond with Gln-11 residue, and the fluorine atom of benzene ring formed a hydrogen bond with Tyr-208 residue, respectively; the benzene ring of Tyr-222 and the pyrimidine ring of 5i yielded a π-π interaction. The molecular electrostatic potential analysis elucidated the nitrogen atom of benzimidazole ring, fluorine atom of benzene ring and sulfur atom of thioether moiety were located in the negative potential regions, whereas some hydrogen atoms of benzene, benzimidazole and pyrimidine rings were located in the positive potential regions. This analysis demonstrated the reason why 5i can form hydrogen bonds with amino acid residues of target protein.

Novel series of triazole-benzimidazole-chalcone hybrid compounds have been synthesized via click chemistry, between different azide derivatives and substituted benzimidazole terminal alkynes bearing a chalcone moiety. The starting alkynes are prepared via base-catalysed nitrogen alkylation of pre-synthetized benzimidazole-chalcone substrates. All the intermediates as well as the final products are fully characterized by 1D and 2D NMR and mass spectrometry techniques. HMBC correlations permits the identification of a unique 1,4-disubstitued triazole-benzimidazole-chalcone isomer. Evaluation of the anti-proliferative potential in breast and prostate cancer cell lines showed that the presence of chloro substituents at the chalcone ring of the triazole-benzimidazole-chalcone skeleton enhanced the cytotoxic effects. The benzyl group linked to the 1,2,3-triazole moiety provides more antiproliferative potential.

The invention relates to the field of medicinal chemistry, and discloses applications of any compound from benzimidazole derivatives Y-0 to Y-12 in prevention and treatment of agricultural plant diseases. It is found through bioactivity test that compounds have certain inhibition activity on six plant fungi including Phyllosticta zeae, botrytis cinerea, sclerotinia sclerotiorum, magnaporthe grisea, rhizoctonia solani and fusarium oxysporum, the inhibition rate of part of the compounds on the six pathogenic fungi under 100 ppm reaches 70% or above, and particularly, the growth of Phyllosticta zeae is almost completely inhibited. The compounds are simple to prepare and cheap and easily available in raw materials, and are expected to be developed into novel bactericides.

Efficient syntheses of some new substituted pyrazoline derivatives linked to substituted benzimidazole scaffold were performed by multistep reaction sequences. All the synthesized compounds were characterized using elemental analysis and spectral studies (IR, 1D/2D NMR techniques and mass spectrometry). The synthesized compounds were screened for their antimicrobial activity against selected Gram-positive and Gram-negative bacteria, and fungi strain. The compounds with halo substituted phenyl group at C5 of the 1-phenyl pyrazoline ring (15, 16 and 17) showed significant antibacterial activity. Among the screened compounds, 17 showed most potent inhibitory activity (MIC = 64 μg mL-1) against a bacterial strain. The tested compounds were found to be almost inactive against the fungal strain C. albicans, apart from pyrazoline-1-carbothiomide 21, which was moderately active.

A series of novel benzimidazole-derived chalcones containing the 1,3,4-oxadiazole moiety were synthesized and characterized by IR, 1H, 13C NMR, and mass spectra and elemental analysis. The synthesized compounds were evaluated for their efficiency as antibacterial agents against two Gram-positive and Gram-negative strains of bacteria along with antifungal activity against three fungal species. Antibacterial activity revealed that tested compounds exhibited potent activity whereas some compounds exhibited moderate antifungal activity as compared to the standards.

A new series of compounds N-(4-(2-(3-(1H-benzo[d]imidazol-2-yl)-5-(aryl)-4, 5-dihydro-1H-pyrazol-1-yl)-2-oxoethoxy)phenyl)acetamides (5a-u) were synthesized and structures of these compounds were elucidated by spectral (IR, 1H NMR, 13C NMR, and mass spectra) analysis. Antimicrobial activity was measured against Escherichia coli (MTCC 443), Pseudomonas aeruginosa (MTCC 1688), Staphylococcus aureus (MTCC 96), Streptococcus pyogenes (MTCC 442), Candida albicans (MTCC 227), Aspergillus niger (MTCC 282), and Aspergillus clavatus (MTCC 1323) by serial broth dilution method. Evaluation of antimicrobial activity revealed that compounds 5f, 5i, 5q, and 5t were the most active antibacterial, while compounds 5e, 5g, 5h, 5j, 5p, 5r, and 5u were the most potent antifungal agents as compared to standard drugs and thus could be promising new lead molecules.

In the present study, a series of novel 6-(1H-benzo[d]imidazol-2-yl)-2-(3- chloro-2-oxo-4-phenylazetidin-1-yl)-4-(aryl)nicotinonitriles 6a-o were efficiently synthesized and evaluated for their in vitro antibacterial activity against Gram-positive (Staphylococcus aureus and Streptococcus pyogenes), Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and fungal (Candida albicans, Aspergillus niger and Aspergillus clavatus) strains. The results of antimicrobial study revealed that compounds 6b, 6c, 6d, 6h and 6i exhibited substantial antibacterial activity while compounds 6c and 6h emerged as the most potent antifungal agents compared to the standard drugs chloramphenicol and ketoconazole, respectively. From the standpoint of SAR studies, it was observed that the presence of electron-withdrawing groups remarkably enhances the antibacterial activity of newly synthesized compounds. Further, the results of preliminary MTT cytotoxicity studies on HeLa cells suggested that potent antimicrobial activity of 6b, 6c, 6d, 6h and 6i is accompanied by low level of cytotoxic concentrations. All the newly synthesized analogues were characterized by IR, 1H NMR, 13C NMR and mass spectral data. Springer Science+Business Media 2013.

1-(1H-Benzo [d] imidazol-2-yl) ethanol (1) on treatment with acetic acid gave 1- (1H-benzo [d] imidazol-2-yl) ethanone (2). Compound 2 when treated with different aldehydes yielded arylidine derivatives (3a-e). Compound 3 on cyclization with chloroacetyl chloride, thioglycolic acid, thiourea and urea yielded azitidinones (4a-e) 4-thiazolidinones (5a-e), pyrimidinethiones (6a-d) and pyramidinones (7a-d) respectively. The structures of the products were established by spectral analysis like IR, 1H NMR and Mass spectroscopy.

1-Benzimidazolyl-3-aryl-prop-2-ene-1-ones 2 have been transformed into N1-substituted pyrazoline derivatives by the interaction with phenyl hydrazine, thiosemicarbazide and hydrazine hydrate in the presence of formic acid under solvent microwave induced protocol. The structure of newly synthesized compounds have been confirmed on the basis of their elemental analysis and spectral data. Newly synthesized compounds have been evaluated for their antimicrobial activity in against E. coli, K. pneumonae, P. aeruginosa and B. subtilis using paper disc method. Some of the compounds have shown significant activity against the pathogens.

Oxidation of 1-alkyl/aralkyl-2-(α-hydroxyalkyl/aryl)benzimidazoles 1 with KMnO4 on neutral alumina under solid phase conditions gives the corresponding ketones, 1-alkyl/aralkyl-2-acyl-benzimidazoles 2. Compound 2a (R2 = CH3) on condensation with aromatic aldehydes in the presence of solid NaOH under solvent-free conditions, yields the corresponding chalcones, 1-alkyl/aralkyl-2-benzimidazole aryl vinyl ketone 3.

2-Acetylbenzimidazole (1) on condensation with various aldehydes yields the chalcones (2a-1) which on cyclization with thiourea/urea in alc. KOH furnish the corresponding 2-imino-4-(benzimidazol-2′ -yl)-6-aryl-6H-2,3-dihydro-1,3-thiazines/1,3-oxazines (3a-1, 4a-1). The compounds have been evaluated for their antibacterial and antifungal activities.

A series of 2-(3-Arylpropenoyl)benzimidazole, 3a-d, and their corresponding N1-methyl analogues, 3e-h, were synthesized from p-substituted benzaldehyde and 2-acetylbenzimidazole or 2-acetyl-1-methylbenzimidazole, respectively. The in vitro alkylating activities of these α-β-unsaturated ketones were investigated using L-cysteine as a model of cellular thioles at pH 7.4 and 37°C. No significant difference between the alkylating activities of 3a-d and 3e-h as expressed from the pseudo first-order rate constants of the reactions of these derivatives with L-cysteine monitored by HPLC. However, significant variations in the rates of alkylation among these derivatives relative to the p-substituted group on the aryl moiety were observed, which is attributable to the electronic parameters of the substituted groups. The in vitro cytotoxic activity provided that the p-nitro derivative; 3d has some selectivity for cell lines of leukemia, renal cancer and breast cancer. The compounds were completely inactive as anti-HIV agents. Molecular modeling for all derivatives was undertaken.

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