RESUMO
The Jequiezinho River is a temporary river. In the urban stretch it is impacted, with perennial flow coming from domestic sewage and rainwater. This study evaluated the geochemical distribution and potential mobility of some metals (Pb, Co, Ca, Cr, Mg, Cu, Fe, Mn, Ni and Zn) in sediments of the Jequiezinho River. Sediment samples were collected at ten different sites along the river. The silt/clay fraction was submitted to acid digestion and sequential extraction with analysis by FAAS. The results indicated that, in the more densely populated region, there was an increase in concentrations of Cr, Ni, Cu, Co, Pb, and Zn. The contents found were compared with the guideline values of TEL (Threshold Effect Levels) and PEL (Probable Effect Levels)ââ, not exceeding the maximum reference limits. The results indicated that Ca, Mg, Mn and Fe presented greater susceptibility to mobility and bioavailability suggesting the geochemical origin responsible for these high concentrations. The multivariate analysis showed that Cr, Ni, Cu, Co, Pb, and Zn presented a similar behavior, especially in locations with higher population density and the discharge of non-discriminated effluents, reflecting the anthropogenic contributions as responsible for the concentration increase.
Assuntos
Metais Pesados , Oligoelementos , Poluentes Químicos da Água , Brasil , Monitoramento Ambiental , Sedimentos Geológicos , Metais Pesados/análise , Rios , Oligoelementos/análise , Poluentes Químicos da Água/análiseRESUMO
Free radicals (FR) act on living organisms and present unpaired electrons in the molecular orbitals of oxygen or nitrogen species. They are classified as redox reactions and account for a wide range of processes in biological systems. Genetic and environmental factors may alter the levels of FR in the cell, leading to deleterious consequences such as membrane lipid peroxidation, protein nitration, enzyme, carbohydrate and DNA damage, ultimately resulting in premature aging and a pro-inflammatory microenvironment as observed in Alzheimer's disease (AD) and autism spectrum disorder (ASD). O2 radical ability to act as a Lewis base and to form a complex with metal transition such as iron and copper (Lewis acids) leads to biomolecules oxidation at physiological pH, thus increasing the possibility of injury and oxidative damage in biological tissues. In this review, we discuss the role of metals, like copper, and the amyloid precursor protein (APP) derivative (s-APP-alpha) as an antioxidant and a possible adjuvant in the treatment of some autistic spectrum disorder symptoms (ASD).
Assuntos
Precursor de Proteína beta-Amiloide , Transtorno do Espectro Autista , Cobre/toxicidade , Radicais Livres , Antioxidantes , Humanos , Estresse OxidativoRESUMO
The new triterpene Delta1-lupenone (1), together with lupeol, beta-amyrin and betulin were isolated from the wood of Byrsonima microphylla (Malpighiaceae). The new compounds 3-hydroxy-2-methoxy-8,8,10-trimethyl-8H-antracen-1,4,5-trione (2), 3,7-dihydroxy-2-methoxy-8,8,10-trimethyl-7,8-dihydro-6H-antracen-1,4,5-trione (3), (2S*,10aR*)-2,8-dihydroxy-6-methoxy-1,1,7-trimethyl-2,3,10, 10a-tetrahydro-1H-fenantren-9-one (4) and (2S,3S)-3'-hydroxy-4',5,7-trimethoxy-flavan-3-ol (5) were also isolated through monitored TLC using the antioxidant beta-carotene reagent. The antioxidant potential of the compounds 2-5 was measured and none of them showed activity. The structures of these compounds were elucidated by chemical and spectroscopic analysis based on NMR techniques (1H, 13C NMR, COSY, nOe difference, HMQC and HMBC), UV and MS.