"Síntese química de derivados hidrossolúveis da rutina: determinação de suas propriedades físico-químicas e avaliação de suas atividades antioxidantes" / The chemical synthesis of water-soluble derivatives of rutin: determination of its physico-chemical properties and evaluation of its antioxidants activities.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Rutin is a glycoside flavonol which belongs to an important class of flavonoids, being extensively found in the nature. It presents a therapeutical importance due to improve the resistance and permeability of capillaries vessels, and is able to suppress free radical processes in some stages. The fruit of the faveiro (Dimorphandra mollis Benth., a Brazilian native species) is one of the sources for the extration in industrial scale of the rutin. Its application in pharmaceutical forms for external use very is limited because it has low solubility in water. With this purpose, it was done the chemical synthesis introducing carboxylate groups on sugar moiety of rutin using pyridin and different anhydrides, such as: succinic, phtalic and the 2-phenyl glutaric at 70 ºC for 24 hours. These three synthesized derivatives had been purificated in chromatographic paper and characterized in 2 systems of different ratios of eluents. Moreover, a comparative study among their physico-chemical properties and of the rutin for the determination of the solubility and the molar extinction coefficient. With this in mind, it was evaluated antioxidant activity of these derivatives with regard to rutin using 2 different assays, as the determination of malondialdehyde by the brain homogenate autoxidation and generation of peroxyl radicals by the thermolysis of a azo compound, with its respective reference standards: α-tocopherol and Trolox. The result of the solubility assay indicated that the succinyl, the phtaloyl and the phenyl glutaroyl rutin had been about 800, 85 and 5,5 times, respective, more soluble in water that the rutin. In respect to relationship to the other assays it was verified that the synthesized derivatives had continued presenting antioxidant activity and absorbing light in its maximum peak next to 392nm, showing that chemical modifications in the flavonoid nucleus had not been made significant. In the assay of anti-radicals, the phtaloyl rutin was the water-soluble derivative what it presented one better result, due one the presence of the aromatic ring that can enhanced the radical-scavenging efficiencies together to the flavonoid nucleus.

ASSUNTO(S)

rutin derivados hidrossolúveis da rutina atividade antioxidante rutina water-soluble derivatives of rutin antioxidant activity

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