A few 4-allyl/amino-5-aryl-1,2,4-triazoles were synthesized and tested for antibacterial and antifungal effects against Escherichia coli, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Aspergillus niger and Candida albicans. 4-Allyl-5-aryl-1,2,4-triazoles were obtained by the oxidative cyclization of the appropriate 1-substituted-4-allylthiosemicarbazides and 4-amino-5-aryl-1,2,4-triazoles were obtained by cyclization of the potassium salts of appropriately substituted dithiocarbazinic acids with hydrazine hydrate. The new synthesized compounds were characterized using IR, 1H- NMR, 13C-NMR and UV spectral data together with elemental analysis.

4-Alkyl/aryl-5-nonanoyl/octadecanoyl-2,4-dihydro-3H-1,2,4-triazoline-3-thiones were synthesized as potential antimicrobial agents. The course of synthesis included the reaction of nonanoyl/octadecanoyl hydrazines with selected alkyl/aryl isothiocyanates. The prepared thiosemicarbazides gave by cyclization the required 1,2,4-triazoles. A number of synthesized compounds were subjected to in vitro testing against two gram-positive, two gram-negative bacteria and two fungi. The literature reports that the antiviral [12] and the antibacterial [13][14] activities of thiourea derivatives were due to the -NH-C(S)-NH-function in the molecule and that the positive/negative changes in the biological activity depended on the nature of its substituents. It is also known that N-substituted fatty acid amides exhibit biological activity [15,16]. A large number of N, O and N, S-heterocyclic compounds prepared by condensation of fatty acids alkyl amides with carbonyl compounds and phosphorous penta sulfide, respectively, have shown excellent bacterostatic and fungistatic action [17].Those observations prompted us to combine the fatty acid amides moiety with thiosemicarbazide structure, to synthesize substituted 1,2,4-triazoline-3-thiones with the same pharmacophoric group and investigate their antibacterial and antifungal activities. Chemistry.The synthetic route to thiosemicarbazides and triazole derivatives is presented in Scheme 1.Ethyl esters of nonanoic and octadecanoic acids (1a-b) were prepared following the standard method [18] by refluxing the acids and the alcohol in presence of sulfuric acid.Further, the desired nonanoyl/octadecanoylhydrazines (2a-b) were obtained treating compounds (1) with hydrazine in ethanol for 12 hours [19,20]. This period of reflux leads to hydrazides with excellent purity and yield. The same hydrazides (2a-b) were converted into 1-nonanoyl/octadecanoyl-4-alkyl/aryl-thiosemicarbazides (3a-b) by refluxing with suitable alkyl/aryl isothiocyanates in ethanolic solution [21,22,23].The reaction of cyclization [24,25] of the thiosemicarbazides with 2 M NaOH solution under reflux for about 4 hours produced 4,5-disubstituted-2,4-dihydro-3H-1,2,4-triazoline-3-thiones (4a-g) in a pure state and in good yield. The new compounds (3a-g, 4a-g) were characterized using ir and 1 H nmr spectroscopy together with elemental analysis.Antibacterial Activites.The filter paper disc method [26,27] was employed for the in vitro study of antibacterial and antifungal effects against Escherichia coli, Bacillus subtilis, Salmonela enteritidis, Staphylococcus aureus, Aspergillus niger and Candida albicans of the compounds (3d-g, 4d-g).This method was performed using Sabouraud dextrose broth and Mueller Hinton broth. These agar media were inoculated with 0.5 ml of the 24 h liquid cultures containing 10 7 microorganisms/mL. Standard 5 mm diameter paper discs impregnated with solutions of each compound (concentrations: 1mg/mL; 5mg/mL and 10mg/mL of DMSO) were placed on the indicated agar mediums. The incubation time was 24 h at ...

Substituted 1,2,4-Triazoles as Biologically Active Compounds. -Title compounds are prepared and subjected to in vitro testing against gram-positive, gram-negative bacteria and two fungi. -(COLANCESKA-RAGENOVIC, K.; DIMOVA, V.; KAKURINOV, V.; GABOR, D. M.; J. Heterocycl. Chem. 40 (2003) 5, 905-908; Fac.