Seher Birteksöz

Antimicrobial Activity of a Series of Thiosemicarbazones and Their Zn II and Pd II Complexes

Thirty-four thiosemicarbazones andS-alkyl thiosemicarbazones, and some of their ZnII and PdII complexes were obtained and purified to investigate antimicrobial activity. MIC values of the compounds were determined by the disc diffusion method againstEscherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Staphylococcus aureus, S. epidermidis, andCandida albicans. The thiosemicarbazones show antibacterial and antifungal effects in free ligand and metal-complex form. Picolinaldehyde-S-methyl- and -S-benzylthiosemicarbazones did not affect the tested microorganisms but their ZnII complexes showed selective activity. The antimicrobial activity is relatively high in Me2SO, but the antimicrobial potential is changed in a certain range with Me2SO, HCONMe2, EtOH and CHCl3.

Antimicrobial activity of FeIII, CuII, AgI, ZnII and HgII complexes of 2-(2-hydroxy-5-bromo/nitro-phenyl)-1H- and 2-(2-hydroxyphenyl)-5-methyl/chloro/nitro-1H-benzimidazoles.

Antimicrobial activity of 2-(2-hydroxyphenyl)-5-R5-1H-benzimidazoles, 2-(2-hydroxy-5-R5′-phenyl)-1H-benzimidazoles and their FeIII, CuII, AgI, ZnII and HgII nitrate complexes was tested towardStaphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, andProteus mirabilis. Antifungal activity was tested againstCandida albicans. Benzimidazole benzene ring substituents increase the antimicrobial activity, phenol ring substituents decrease it. The ligands show an antibacterial effect against onlyS. aureus whereas AgI and HgII complexes of the ligands have a higher activity with respect to the other complexes to all the bacteria. On the other hand, FeIII complexes show a considerable activity againstS. aureus andS. epidermidis.

Antimicrobial activity of some 2- and 3-pyridinyl-1H-benzimidazoles and their FeIII, CuII, ZnII, and AgI complexes

Abstract2-(2-Pyridinyl)-(LI), 2-(6-methyl-2-pyridinyl)-(LII), 2-(6-methyl-2-pyridinyl)-5-methyl-(LIII), 2-(3-pyridinyl)- (LIV), 2-(3-pyridinyl)-5-methyl-1H-benzimidazoles (LV) and their complexes with Fe(NO3)3, Cu(NO3)2, Zn(NO3)2, and AgNO3 were synthesized and antibacterial activity of the compounds was tested towardStaphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Proteus mirabilis and antifungal activity againstCandida albicans. The methyl groups ofLIII increase the antimicrobial activity. The AgI complexes have considerable activity toward the microorganisms. Some ZnII complexes show an antimicrobial effect againstS. aureus andS. flexneri, although the ligands themselves have no effect. CuII complexes have a considerable antibacterial effect toS. aureus andS. epidermidis.

Antimicrobial activity of 1,2-bis-[2-(5-R)-1H-benzimidazolyl]-1,2-ethanediols, 1,4-bis-[2-(5-R)-1H-benzimidazolyl]-1,2,3,4-butanetetraols and their FeIII, CuII, and AgI complexes

Abstract1,2-Bis-[2-(5-H/Me/Cl/NO2)-1H-benzimidazolyl]-1,2-ethanediols (L1–L4), 1,4-Bis-[2-(5-H/Me/Cl)-1H-benzimidazolyl]-1,2,3,4-butanetetraols (L5–L7) and their complexes with FeCl3, CuCl2, and AgNO3 were synthesized; antibacterial activity of the compounds was determined towardStaphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Proteus mirabilis, and antifungal activity againstCandida albicans. The AgI complexes have considerable activity toward the microorganisms. Some AgI complexes show higher activity towardS. epidermidis than AgNO3 and cefuroxime. Cu(L3)Cl2 and Fe(L3)Cl3 show an antifungal effect onC. albicans butL3 itself has no activity.

Antimicrobial activity of ZnII, CdII, and HgII complexes of 1,2-bis-[2-(5-R)-1H-benzimidazolyl]-1,2-ethanediols and 1,4-bis-[2-(5-R)-1H-benzimidazolyl]-1,2,3,4-butanetetraols.

Abstract1,2-Bis-[2-(5-H/Me/Cl/NO2)-1H-benzimidazolyl]-1,2-ethanediols (L1–L4), 1,4-bis-[2-(5-H/Me/Cl)-1H-benzimidazolyl]-1,2,3,4-butanetetraols (L5–L7) and their complexes with ZnCl2, CdCl2 and HgCl2 were synthesized and antibacterial activity of the compounds was tested towardStaphylococcus aureus, S. epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Proteus mirabilis and antifungal activity againstCandida albicans. HgII complexes have a considerably higher antimicrobial activity against all microorganisms. Some HgII complexes show higher antifungal activity than clotrimazole towardC. albicans. Zn2(L3)Cl4, Zn2(L4)Cl4, and Cd(L3)Cl2 were moderately effective againstS. aureus andS. epidermidis; Cd(L4)Cl2 exhibited a weak activity only againstS. epidermidis.