Thermal and spectroscopic studies of the antioxidant food additive propyl gallate.

Literature mentions propyl gallate (PG) as a non-toxic synthetic antioxidant that can be used as a food additive due to its high tolerance to heat. It is important to understand the thermal properties and to identify the decomposition products of this substance, since it has been reported to be thermally stable at temperatures as high as 300 °C. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry-photovisual (DSC-photovisual), coupled thermogravimetry-infrared spectroscopy (TG-FTIR) analyses and spectroscopic techniques were used to study the food additive PG. The TG-DTA curves, which were performed with the aid of DSC-photovisual, provided information concerning the thermal stability and decomposition profiles of the compound. From the TG-FTIR coupled techniques, it was possible to identify n-propanol as a possible volatile compound released during the thermal decomposition of the antioxidant. A complete spectroscopic characterization in the ultraviolet, visible, near and middle infrared regions was performed in order to understand the spectroscopic properties of PG.

Differential effects of organic and inorganic selenium compounds on adenosine deaminase activity and scavenger capacity in cerebral cortex slices of young rats.

Selenium (Se) has anti-inflammatory and antioxidant properties and is necessary for the development and normal function of the central nervous system. This study was aimed to compare the in vitro effects of 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one (C21H2HOSe; organoselenium) and sodium selenate (inorganic Se) on adenosine deaminase (ADA) activity, cell viability, lipid peroxidation, scavenger of nitric oxide (NO) and nonprotein thiols (NP-SH) content in the cerebral cortex slices of the young rats. A decrease in ADA activity was observed when the slices were exposed to organoselenium at the concentrations of 1, 10 and 30 µM. The same compound showed higher scavenger capacity of NO than the inorganic compound. Inorganic Se was able to protect against sodium nitroprusside-induced oxidative damage and increased the NP-SH content. Both the compounds displayed distinctive antioxidant capacities and were not cytotoxic for the cerebral cortex slices in the conditions tested. These findings are likely to be related to immunomodulatory and antioxidant properties of this compound.

Estudo da colonizacao bacteriana do recem-nascido em alojamento conjunto. / Bacterial colonization in newborn infants in rooming-in care

Os autores estudam comparativamente, a colonizacao bacteriana do recem-nascido no bercario e no alojamento conjunto (AC). Verificaram, principalmente, que a colonizacao bacteriana aumenta no recem-nascido do bercario do primeiro para o terceiro dias, aumento este, estatisticamente significativo e a custa de flora predominantemente Gram-negativa.No terceiro dia de vida, a flora colonizada pelos recem-nascidos em AC diferiu daquela dos recem-nascidos no bercario, constatando-se que os recem-nascidos em AC colonizaram com germes Gram-positivos. Esta diferenca encontrada foi estatisticamente significativa. Culturas de material de maes no AC mostraram que em 26% das pacientes houve crescimento de germes. As bacterias identificadas nao se relacionaram com a colonizacao dos recem-nascidos do AC, no terceiro dia de vida. Estes dados permitiram concluir que recem-nascidos no bercario estao sujeitos a colonizacao por germes de patogenicidade maior que aqueles em AC