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Metals and agrochemicals are among the main aquatic contaminants, being able to trigger oxidative stress in exposed organisms. The objective of this work was to evaluate the correlation between the level of oxidative stress biomarkers in Aegla crabs (Crustacea, Anomura) with (i) the set of metals present in the streams sediment and (ii) with land uses of three hydrographic basins. The study was carried out in streams (≤ 2nd order) of hydrographic basins in southern Brazil (Basins of Rio Suzana, Rio Ligeirinho-Leãozinho and Rio Dourado). In these streams were quantified the land uses and Cu, Cr, Cd, Fe, Mn and Zn concentrations in the sediment. The enzymes Catalase (CAT) and Glutathione Reductase (GR), as well as the level of membrane lipid peroxidation (TBARS), were analyzed in adult females. The PCA analysis showed that the distribution of metals was different between the basins. Cd, Cr and Fe were correlated positively with CAT and negatively with TBARS and GR. The Dourado basin had the lowest concentrations of these three metals and the highest levels of TBARS. However, in Dourado basin there is predominance of agriculture land use, and TBARS was positively correlated with agricultural land use. Besides in Dourado basin, GR activity was higher than in the others basins, indicating a compensatory response in relation to CAT inhibition. The basins of Suzana and Ligeirinho-Leãozinho rivers had lower TBARS values, which may be due to the induction of CAT in response to metals accumulated in sediment. In summary, this work indicates that in the basins with a higher concentration of toxic metals there is an adaptive response of CAT induction, which reduces TBARS in Aegla. On the other hand, in the basin with lower metallic contamination, TBARS occurrence was primarily influenced by agricultural land use. Resumo Os metais e agroquímicos estão entre os principais contaminantes aquáticos, podendo desencadear estresse oxidativo em organismos expostos. O objetivo deste trabalho foi avaliar uma possível correlação entre o nível de biomarcadores de estresse oxidativo em Aegla (Crustacea, Anomura) com (i) o conjunto de metais presentes no sedimento e (ii) com os usos da terra, em três bacias hidrográficas distintas. O estudo foi realizado em riachos (≤ 2ª ordem) de bacias hidrográficas do Sul do Brasil (Bacias do Rio Suzana, do Rio Ligeirinho-Leãozinho e do Rio Dourado), as quais foram caracterizadas em função do percentual de usos da terra e do nível de Cu, Cr, Cd, Fe, Mn e Zn no sedimento. As enzimas Catalase (CAT) e Glutationa Redutase (GR), bem como o nível de peroxidação lipídica das membranas (TBARS), foram analisadas em fêmeas adultas. Uma análise de PCA mostrou que a distribuição de metais foi distinta entre as bacias. Cd, Cr e Fe no sedimento correlacionaram positivamente com a CAT e negativamente com TBARS e GR. Entretanto, a bacia do Dourado apresentou os menores níveis destes três metais e os maiores níveis de TBARS, o que pode ser justificado pelo predomínio da agricultura nesta bacia, já que o TBARS correlacionou positivamente com o percentual de uso agrícola. Nesta bacia, a atividade da GR foi mais alta do que nas outras, indicando uma resposta compensatória em relação a inibição da CAT. As bacias do rio Suzana e rio Ligeirinho-Leãozinho apresentaram valores menores de TBARS, o que pode decorrer da indução da CAT em função dos metais acumulados no sedimento. Em síntese, este trabalho indica que nas bacias com maior concentração de metais tóxicos ocorre uma resposta adaptativa de indução da CAT, o que reduz os níveis de TBARS em Aegla. Por outro lado, na bacia com menor contaminação metálica os níveis de TBARS foram primariamente influenciados pelo uso agrícola.

Vitamin B1 (C12H67ClN4OS.HCl, molecular weight = 337.33 g mol–1), also called thiamine, has great importance in the food industry in general. Thiamine is a vitamin belonging to the B complex, and can be found in the cuticle of rice, brewer’s yeast, grains, egg yolk, liver, kidney, pork, fish, peanut, walnut, legumes, as well asin green and leafy vegetables. It acts in different parts of the body and plays a major role in the nervous, muscular and cardiovascular systems, in addition to assisting in glucose metabolism. Thiamine deficiency causes brain damage and in some cases it may be irreversible. Among the diseases caused by vitamin B1 deficiencies are: Beriberi, Wernicke’s encephalopathy and Korsakoff’s syndrome1. Thiamine is not stored in large amounts in the body, with provision from the daily diet being necessary. Thiamine is unstable in alkali conditions and is heat stable at acidic pH values. Thiamine solubility data in water are widely found in the literature. However, solubility data in alternative solvents such as dimethylsulfoxide (DMSO) and DMSO + water mixtures may be important for studies of separation and purification of the feedstock. On the other hand, the crystallization processes of thiamine require a large amount of accurate solubility data. Unfortunately, there is a lack of solubility data that indicates the solubility dependence as a function of temperature and of the initial solvent mixture composition2,4. Thus, obtaining solubility data for thiamine under known conditions of temperature, pressure and concentration of the initial mixture of solvents is important in order to improve manufacturing processes and purification (crystallization) of this vitamin.

The present study reports the synthesis and characterization of complexes formed among humic (HA) and fulvic acids (FA) derived from poultry wastes and ions Cu2+, Fe2+ and Zn2+. The release of such metals in a buffer solution simulating the soil solution was also evaluated. After complexation, the Fourier transform infrared (FTIR) spectra presented alterations in the absorption bands related to changes in the humic structure, thus indicating the complexation with phenolic and carboxylic groups. Thermogravimetric analyses demonstrated that complexed metals decreased the thermal stability of humic substances. Analyses by atomic absorption spectroscopy (AAS) demonstrated that the release of metals is directly related to the origin of the sample, type of interaction of metal and humic structure and conditions of the medium in which the complex is inserted.

Binding and localization of the vasodilator and antitumor drug coactivator dipyridamole (DIP) and of its three derivatives, RA14, RA47 and RA25 (DIPD), to cationic (cetyltrimethylammonium chloride), anionic (sodium dodecylsulfate), zwitterionic (N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate), and neutral (t-octylphenoxypolyethoxyethanol) micelles was studied using fluorescence, optical absorption and 1H NMR spectroscopy. The analysis of NMR, optical absorption and fluorescence data indicates that the depth of localization of the drugs in the micelles from the surface decreased in the order DIPRA14RA47RA25. The binding constants for the neutral drug forms change in the same order in the range of 1400-3100 M-1 for DIP to 80-300 M-1 for RA25. This order is identical with the reported biological activity of DIPD. For the protonated drugs in zwitterionic or neutral micelles the binding constants are reduced by a factor of 20-75.