Fitato (PHYT, mio-inositol 1,2,3,4,5,6-hexakisfosfato) é um produto natural com forte efeito sobre a biodisponibilidade de minerais, especialmente o ferro. Neste trabalho, investigamos os efeitos antioxidantes do PHYT em modelos de transtornos de sobrecarga de ferro (ferro lábil plasmático e reservatório de ferro lábil). PHYT apresentou um efeito antioxidante considerável, com a vantagem de ser permeável às células e ser um constituinte normal da dieta humana. Nossos resultados sugerem que o PHYT pode auxiliar as defesas do organismo contra estresse induzido por sobrecarga de ferro.

Phytate (PHYT, myo-inositol 1,2,3,4,5,6-hexakisphosphate) is a natural product with strong effect on the bioavailability of minerals, especially iron. In this work, we investigated the antioxidant effects of PHYT on models of iron overload disorders (labile plasma iron and labile iron pool) both in solution and in HeLa cells. PHYT has a considerable antioxidant effect, with the benefit of being cell permeant and a normal constituent of human diet. Our results suggest that PHYT may assist organism defenses against iron-overload stress.

Cinco complexos de ródio(II) de fórmula geral [Rh2(ponte)4] (ponte = acetato, propionato, butirato, trifluoroacetato e trifluoroacetamidato) tiveram suas afinidades em relação à albumina humana (HSA) determinadas por espectrofotometria, observando-se no caso dos alquilcarboxilatos uma correlação inversa com suas lipossolubilidades. A difusão dos complexos livres ou ligados à proteína para células de Ehrlich in vitro parece primordialmente governada pelo caráter hidrofóbico do complexo. O complexo [Rh2(tfc)4] apresentou afinidade pela proteína (K = 214,1), além de partição celular tanto em ausência (32,1%) como na presença (48,6%) de HSA. Desta forma, o composto HSA: [Rh2(tfc)4] teve sua ação antitumoral investigada em camundongos Balb-c portadores de ascite de Ehrlich, mostrando que a HSA pode ser um reservatório para o complexo de ródio.

The affinities for human albumin (HSA) of five rhodium(II) complexes of general formula [Rh2(bridge)4] (bridge = acetate, propionate, butyrate, trifluoroacetate and trifluoroacetamidate) were determined by spectrophotometry. In the case of the alkylcarboxylates, an inverse correlation of affinity with their liposolubilities was observed. Diffusion of the free or protein-bound complexes into Ehrlich cells in vitro seems to be primarily governed by the hydrophobic character of the complex. The complex [Rh2(tfc)4] exhibited affinity towards the protein (K = 214.1) as well as cell partition both in the absence (32.1%) and presence (48.6%) of HSA. The compound HSA: [Rh2(tfc)4] has had its antitumoral action in tumor-bearing Balb-c mice investigated, showing that HSA can be a drug reservoir for the rhodium complex.

The electrochemistry field has increased in recent years, specially in the search for new sensors to monitor specific analyte in complex samples. In order to improve electrodes, many rhodium compounds have been used as electron mediators for novel sensors development. The most used compounds for this purpose are metal, metal complexes and some organic dyes. Rhodium complexes are known by their good catalytic properties and it could be useful in the sensor field. However, there are only a few reports, on the use of rhodium complexes in sensors and biosensors. A brief review of the electrochemistry of rhodium complexes and some discription of their properties which make those compounds suitable for development of sensor and biosensor.