Unsymmetrically substituted imidazolium salts: synthesis, characterization and antimicrobial activity

ABSTRACT Unsymmetrically substituted imidazolium salts were synthesized and characterized using 1H-NMR and 13C-NMR. The antimicrobial activities of the salts were evaluated using the agar-well diffusion method against 14 bacteria and five yeasts. The minimal inhibitory concentrations (MIC) against seven bacteria and one yeast were also determined. Among the test compounds applied, 1, 2, 3, 6 and 11 showed activities against Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, Bacilllus cereus ATCC 11778, Bacillus subtilis ATCC 6633, Bacillus thuringiensis, Listeria monocytogenes ATCC 19112 and Candida trophicalis. However, compounds 1, 2 and 3 showed the highest antimicrobial activities against Micrococcus luteus ATCC 9341, Stapylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, Bacilllus cereus ATCC 11778 and Bacillus subtilis ATCC 6633 with inhibition zones of 14-20 mm. In addition, compound 6 have only demonstrated activities against Candida trophicalis while compounds 4, 5, 7, 8, 9, 10, 12, 13 and 14 had no effect on test microorganisms.

Bioavailability of iodine and hardness (magnesium and calcium salt) in drinking water in the etiology of endemic goitre in Sundarban delta of West Bengal (India).

Endemic goitre has been reported from the ecologically diverse Sundarban delta of West Bengal (India). To study the etiological factors for the persistence of endemic goitre, bioavailability of iodine and hardness of water used for drinking in the region were evaluated because these common environmental factors are inversely and directly related with goitre prevalence in several geographical regions. For the present study from 19 Community Development Blocks of Sundarban delta, 19 areas were selected at random. From each area at least 8 drinking water samples were collected and analyzed for iodine and the hardness (calcium and magnesium salt content). Iodine content in the drinking water samples was found in the range from 21 to 119 mg/L and total hardness of drinking water was found to range from 50 to 480 ppm. Presence of magnesium salt was found higher than the calcium salts in most of the samples. These findings suggest that the entire delta region is environmentally iodine sufficient but water is relatively hard and thus possibility of hardness of water for the persistence of endemic goitre may not be ruled out.

Actividad biológica y enzimática en suelos afectados por sales del Alto Valle de Río Negro y Neuquén / Biological and enzymatic activities in salts affected soils from Alto Valle de Río Negro and Neuquén

En el presente trabajo se estudiaron los cambios que provocó el lavado de cinco suelos afectados por sales sobre la actividad biológica (número de bacterias g-1y producción de CO2) y enzimática (catalasa, deshidrogenasa, ureasa y fosfotriesterasa) de los mismos. El lavado disminuyó la conductividad eléctrica (CE) y modificó el tipo de sales dominantes en los suelos. La producción de CO2 y la actividad de la fosfotriesterasa fue significativamente mayor (p<0,05) en un suelo lavado (Torrifluventes Típicos Centenario); el incremento fue del 88% y 71%, respectivamente. Los resultados demostraron que la disminución de la salinidad por lavado no ocasionó comportamientos significativamente diferentes, en la mayoría de los parámetros bióticos estudiados, bajo las condiciones en que se realizó este estudio.

Changes in the biological activity (number of bacteria g-1and CO2 production) and in the enzymatic activity (catalase, deshidrogenase, urease and phosphotriesterase) caused by the leaching of five soils affected by salts have been studied. The leaching decreased the electric conductivity (CE) and modified the type of dominant salts in the soils. Production of CO2and the activity of the phosphotriesterase was significantly higher (p<0,05) in a leached soil (Torrifluventes Typical Centennial); the increment were 88% and 71%, respectively. The results showed that the decrease of the salinity by leaching did not produce significantly different results in most of the biotic parameters analised.