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2-[6-(Morpholin-4-yl)pyridin-3-ylamino]acetohydrazide (4) was obtained starting from 6-morpholin-4-ylpyridin-3-amine (2) via the formation of ester (3) and then converted to the corresponding Schiff bases (5, 6) with the reaction with aromatic aldehydes. The carbothioamide (9), obtained from the reaction of hydrazide with phenylisothiocyanate, was converted to the corresponding 1,2,4-triazole (11) and 1,3,4-thiadiazole (12) derivatives by the treatment with NaOH or H2SO4, respectively. The cyclocondenzation of 9 with 4-chlorophenacyl bromide or ethyl bromoacetate produced the corresponding 1,3-thiazole (10) or 1,3-thiazolidine derivatives (13), respectively. Antimicrobial and antiurease activities of newly synthesized compounds were investigated. Some of them were found to be active on M. smegmatis, and they displayed activity toward C. albicans and S. cerevisiae in high concentration. Compound 10 proved to be the most potent showing an enzyme inhibition activity with an IC50 = 2.37 ± 0.19 μM.

4-Aryl-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-(thi)oles 5-7, obtained starting from nicotinic acid hydrazide were converted to the corresponding Mannich bases 12-24 by the reaction with several heterocyclic amines in the presence of formaldehyde. The synthesis of S-alkylated compounds 8-11 was performed from the reaction of the corresponding triazol-5-thioles with various alkyl halides. The condensation of carbo(thio)amides 2-4 with 4-chlorophenacyl bromide afforded the corresponding 1,3-thia(oxa)zol-2(3H)-ylidene]pyridine-3-carbohydrazides 25-27. 1,3-Thia(oxa)zolidine derivatives 28-30 were obtained from the cyclization reaction between compounds 2-4 and ethyl bromoacetate. All newly synthesized compounds were screened for their antimicrobial, antiurease, and antilipase activities. The biological activity studies revealed that all the compounds screened showed good or moderate antimicrobial, antiurease, and/or antilipase activity.

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Twenty-five new hydroxy-and methoxy-substituted 4,6-diarylpyrimidin-2(1H)-ol (20-34) and 4,6-diarylpyrimidine-2(1H)-thiol derivatives (35-44) were synthesized from the reaction of the corresponding 1,3-diaryl-2-propene-1one compounds (1-19) with urea or thiourea using the solid-phase microwave method. All the new synthetic compounds (20-44) were evaluated with regard to their α-glucosidase activity. However, only compounds 22-25, 27, 31, 34, 35, 37, and 40 exhibited a greater inhibitory effect than standard acarbose. The IC 50 values of the active compounds ranged between 2.36 and 13.34 µ M. The 25 new compounds were also screened for their in vitro pancreatic lipase activity and compounds 20-27 and 35-39 were found to be active. Of these compounds 26, 27, and 39 exhibited the best antilipase activities at concentrations of 0.40 ± 0.06, 0.26 ± 0.07, and 0.29 ± 0.026 µ M. All the new compounds (20-44) were evaluated for their in vitro antimicrobial activity for nine test microorganisms. Compounds 20-24 and 35-39 were determined to possess a significant broad spectrum against the gram-positive bacteria Escherichia faecalis, Staphylococcus aureus, and Bacillus cereus among the tested bacterial agents. Compounds 20-24 and 35-39 exhibit the best activity against Mycobacterium smegmatis, with minimum inhibitory concentrations of 62.5-500 µ g/mL, indicating their potential use as antituberculous agents.

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Fifty-five ampicillin-resistant (Amp r ) Escherichia coli strains were isolated from 51 drinking water points in Rize region containing abundant fresh water sources in Turkey during the years 2000 to 2002 and from January to February 2004. The large number of organisms (nearly 57%) exhibited resistance to three or more antibiotics commonly used in human and veterinary medicine. These strains displayed a multiresistant phenotype. Nearly half of the strains (27%) expressed resistance to ceftazidime, but these strains were not an extended-spectrum β-lactamase-producer according to the results of double-disk synergy test. All isolates were then screened for the carriage of TEM-type β-lactamase gene (bla TEM ) by polymerase chain reaction. TEM-type β-lactamase genes were found in six (11%) isolates. Sequence analysis showed TEM-1 type genes. However, isoelectric focusing analysis did not confirm the production of TEM-1 type β-lactamase except for one strain. Conjugation experiments showed that resistance to ampicillin, tetracycline or trimethoprim/sulfamethoxazole was transferable in six (11%) isolates. Emergence of transferable antibiotic resistance and bla TEM-1 gene in E. coli strains from public drinking waters possesses a significant public health risk.