Muammer Kiraz

Synthesis, characterization and pharmacological properties of some 4-arylhydrazono-2-pyrazoline-5-one derivatives obtained from heterocyclic amines.

The synthesis of a new series of 4-arylhydrazono-2-pyrazoline-5-ones 7-24 and 22a is described. Structures of the synthesized compounds were confirmed using UV, IR, 1H-NMR, 13C-NMR and EI-mass spectral data. These compounds were tested in vitro against one Gram-positive and two Gram-negative bacterial strains, two mycobacterial strains and a fungus, Candida albicans. Compound 22 was found to be more active against Staphylococcus aureus than the other compounds at a concentration of 15.6 microg/mL. Some related compounds were evaluated for anticonvulsant activity. Compound 11 showed 40% protection against pentylenetetrazole-induced seizures in albino Swiss mice. In vitro antituberculosis activity of 4-arylhydrazono-2-pyrazoline-5-ones 7-12, 14-24, 22a and coupling products 6a-f were tested on Mycobacterium tuberculosis H37Rv. Of these compounds, only 24, which exhibited > 90% inhibition in the primary screen at 12.5 microg/mL against this strain was re-examined for determination of its actual MIC. However, level II assay revealed that the MIC value was not less than 12.5 microg/mL. The same compound was also tested against Mycobacterium avium, which was observed not to be susceptible to 24.

New 6-Phenylimidazo[2,1-b]thiazole Derivatives: Synthesis and Antifungal Activity

Summary. New benzylidene-(6-phenylimidazo[2,1-b]thiazol-3-yl)-acetic acid hydrazides, 4-alkyl-1-((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetyl)-3-thiosemicarbazides, 2-aryl-3-((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetamido)-4-thiazolidinones, and 3-alkyl-2-(((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetyl)-hydrazono)-4-thiazolidinones were synthesized from 6-phenylimidazo[2,1-b]thiazole-3-acetic acid hydrazide and evaluated for antifungal activity against three dermatophyte strains using ketoconazole as standard. Several of them were found as effective as the standard against Trichophyton rubrum and Microsporum audounii (MIC=6 μg/cm3), whereas the activity of N-benzylidene-(6-phenylimidazo[2,1-b]-thiazol-3-yl)-acetic acid hydrazide against M. audounii was superior to the standard (MIC=3 μg/cm3). 2-(4-Methylphenyl)-3-((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetamido)-4-thiazolidinone and 2-(4-chlorophenyl)-3-((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetamido)-4-thiazolidinone showed the highest activity against Trichophyton mentagrophytes var. erinacei NCPF-375 (MIC=3 μg/cm3).Zusammenfassung. Ausgehend von 6-Phenylimidazo[2,1-b]-thiazol-3-essigsäurehydrazid wurden neue Benzyliden-(6-phenylimidazo-[2,1-b]-thiazol-3-yl)-essigsäurehydrazide, 4-Alkyl-1-((6-phenylimidazo[2,1-b])thiazol-3-yl)-acetyl)-3-thiosemicarbazide, 2-Aryl-3-((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetamido)-4-thiazolidinone und 3-Alkyl-2-((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetyl)-hydrazono)-4-thiazolidinone dargestellt und hinsichtlich ihrer fungistatischen Aktivität untersucht. Einige der Verbindungen erwiesen sich als aktiv gegen Trichophyton rubrum und Microsporum audounii (MIC=6 μg/cm3). Es stellte sich heraus, daß N-benzyliden-(6-phenylimidazo[2,1-b]-thiazol-3-yl)-essigsäurehydrazide gegen M. audounii aktiver als die Standardsubstanz Ketokonazol ist (MIC=3 μg/cm3). 2-(4-Methylphenyl)-3-((6-phenylimidazo[2,1-b])thiazol-3-yl)-acetamido)-4-thiazolidinon und 2-(4-Chlorophenyl)-3-((6-phenylimidazo[2,1-b]thiazol-3-yl)-acetamido)-4-thiazolidinon zeigen die größte Aktivität gegen Trichophyton mentagrophytes var. erinacei NCPF-375 (MIC=3 μg/cm3).

Synthesis of new triazolyl-N,N-dialkyldithiocarbamates as antifungal agents.

N,N-Dialkylditihiocarbamate derivatives have been well known as broad-range fungicides. In this study, the triazole derivatives of ten newN,N- disubstituted dithiocarbamates (3a-j) were synthesized and their structures were identified by spectral and elemental analysis. Results of the antifungal activity studies showed that some of the compounds tested were active againstM. canis, M. gypseum, andT. rubrum at the concentration of 12.5 μg/mL when clotrimazol was used as a standard.

New 6-(4-Bromophenyl)-imidazo[2,1-b]thiazole Derivatives: Synthesis and Antimicrobial Activity

Summary. New 4-alkyl/aryl-1-((6-(4-bromophenyl)-imidazo[2,1-b]thiazol-3-yl)-acetyl)-3-thiosemicarbazides and 3-alkyl/aryl-2-(((6-(4-bromophenyl)-imidazo[2,1-b]thiazol-3-yl)-acetyl)-hydrazono)-4-thiazolidinones were synthesized from 6-(4-bromophenyl)-imidazo[2,1-b]thiazole-3-acetic acid hydrazide. Their structures were elucidated by elemental analyses and spectroscopic data. All compounds were tested for antibacterial and antifungal activities. The antimicrobial activities of the compounds were assessed by the microbroth dilution technique. The compounds were also evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv (ATCC 27294); they exhibited varying degrees of inhibition in the in vitro primary screening at 6.25 μg · cm−3. The most active compound was 3-(4-nitrophenyl)-2-(((6-(4-bromophenyl)-imidazo[2,1-b]thiazol-3-yl)-acetyl)-hydrazono)-4-thiazolidinone.

New cyclohexylidenehydrazide and 4-aza-1-thiaspiro[4.5]decan-3-one derivatives of 3-phenyl-4(3H)-quinazolinones

Abstract In this study, the synthesis of (3-phenyl-4(3 H )-quinazolinon-2-yl)mercaptoacetic acid cyclohexylidenehydrazides and 4-[(3-phenyl-4(3 H )-quinazolinon-2-yl)mercaptoacetylamino]-4-aza-1-thiaspiro[4.5 ]decan-3-ones and the results of the study on their antifungal activity are reported. Most of the tested compounds were found to be active against Microsporum gypseum NCPF-580, Microsporum canis, Tricophyton mentagrophytes NCPF 375 var. erinacei and Tricophyton rubrum at 25 μg/ml.

Synthesis, Characterization, and Evaluation of Antimicrobial Activity of Some 1,2,4-Triazole Derivatives Bearing an Antipyryl Moiety

Summary. Some novel 4-[[2-[[5-(2-furanyl)-4-alkyl/aryl-4H-1,2,4-triazol-3-yl]thio]-acetyl/propionyl]-amino]-1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazoles were synthesized and evaluated for in vitro antibacterial activity against Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, and Enterococcus faecalis ATCC 29212 and antifungal activity against Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019, Candida krusei ATCC 6258, Candida parapsilosis, Trichophyton mentagrophytes var. erinacei NCPF 375, Microsporum gypseum NCPF 580, and Trichophyton rubrum using the microbroth dilution method. All of the compounds were found to be ineffective against the above bacteria within the applied MIC ranges. On the other hand, they were effective against fungi to different degrees. Three compounds showed high activity against C. parapsilosis and T. mentagrophytes var. erinacei NCPF 375 (MIC = 8 μg cm−3). The in vitro antimycobacterial activity of the new compounds was also investigated against Mycobacterium tuberculosis H37RV (ATCC 27294) in BACTEC 12B medium using a broth microdilution assay, the Microplate Alamar Blue Assay (MABA). Compounds exhibiting fluorescence were tested in the BACTEC 460 radiometric system. The most active compound was found with 66% inhibition at >6.25 μg cm−3.