Seda Yuksekdanaci

In this study, a new series of chiral benzimidazole-glycosyl thiourea derivatives (5-10) were synthesized and evaluated for their inhibitory effects against hCA I, hCA II, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The structures of the benzimidazole-glycosyl thiourea compounds were determined by FTIR, 1H-NMR, 13C-NMR and elemental analysis. The KI values for the CA isoenzymes of the synthesized materials ranged from 6.03 to 42.98 nM. KI values for cholinesterase enzymes were shown to be between 5.32 and 39.14 nM. It was observed that compound 10 is the best hCA I inhibitor (KI:6.03 nM), compund 9 is the best hCAII inhibitor (KI:17.29 nM) and compound 8 is the best AChE (KI:5.32 nM) and the best BChE (KI:18.73 nM) inhibitor.

Schiff and azo-Schiff base derivatives were synthesized, identified and evaluated for their antimicrobial and antifungal activities against gram-positive bacteria, gram-negative bacteria and fungi such as Escherichia coli, Pseudomonas aureginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium, Saccharomyces cerevisiae and Candida albicans. Chiral amides (2a-e) were synthesised by using D-Phenylglycine, L-Phenylalanine, L-valine, L-isoleucine and L-methionine. Experimental studies include the use of chiral amide derivatives (2a-e) of the five amino acids to synthesize the Schiff and azo-Schiff base derivatives of amides (3a-e, 4a-c and 4e). The structures of the compounds were determined by spectroscopic analyses (FTIR, 1H-NMR, 13C-NMR) and elemental analysis. Among the tested compounds, compound 3b and 3d were found to show the most potent inhibitory action against Gram positive and Gram negative bacteria.

Background: Benzimidazole derivatives are an important class of heterocyclic compounds in organic chemistry as they are related to a wide range of biological properties, including antimicrobial activity. Methods: A series of 1-naphthoyl and benzoyl benzimidazole derivatives were synthesised, identified and screened for their antimicrobial activities against a number of different test organisms such as Escherichia coli, Pseudomonas aureginosa, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus, Salmonella typhimurium, Candida albicans (yeast). Results and Discussion: Benzimidazole derivatives (3a-d) were synthesised by using 4 different aminoacids. L-methionine, L-isoleucine, D-Phenylysine and L-Phenylamine as starting materials in the study. Experimental studies involve the use of benzimidazole derivatives (3a-d) of the selected amino acids to synthesize the benzoyl and naphthoyl derivatives of benzimidazole (4a-d, 5a-c). The structures of the synthesized compounds were confirmed by spectroscopic analyses (FTIR, 1HNMR, 13C-NMR) and elemental analysis. Conclusion: In this study, only one compound (5a) showed a low MIC value against the eukaryotic microorganism C. albicans. The other six compounds showed higher antimicrobial activities against the prokaryotes C. albicans which is a normal flora in the mouth but is one of the organisms that cause infections leading to the weakening of the human immune system. Compound 5a is a candidate for future alternative antimicrobial drugs against C. albicans infections. In addition, compound 5a has a potential to be used as an inhibitor against P. aureginosa for the treatment of cystic fibrosis.

In this study, new chiral Schiff bases (3-9) obtained from the reaction of chiral amide derivatives with different substituted aromatic aldehyde were synthesized. All synthesized compounds structures were characterized by FTIR, 1H-NMR, 13C-NMR and elemental analysis. All of the new synthesized compounds were tested in vitro against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella thyphimirium, Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans for their antibacterial and antifungal activities. All compounds have shown moderate to good antibacterial activity against Gram-positive and Gram-negative bacteria. Among the compounds tested compound 7 showed most potent inhibitory action against test organisms.