Uric Acid Reaction With DPPH Radicals at the Micellar Interface

Abstract

buffer/etanol > neutral micelles anionic micelles These results can be explained in terms of the compartmentalization of the reactants in different environments and the effect of electrostatic interactions in modulating the access of the urate anion to the micellar interface. Experiments aimed to determine if urate is able to react with alpha-tocopheroxyl radicals regenerating a-tocopherol were uncesessful, indicating that urate is not able to delay vitamin E consumption in the presence of lipid - soluble free radicals]]>

Genesis and development of DPPH method of antioxidant assay

“…Uric acid reaction with micelle-incorporated DPPH was explained by Abuin et al (2002), while Bandoniene et al (2002) detected the activity of radical scavenging compounds in mixed methanol-water solution using DPPH and HPLC-DPPH method. Ionita et al (2000) used water-soluble derivate of DPPH for the study of oxidation kinetics of amino acid.…”

Poly(ethylene oxide)-polyelectrolyte blends: viscometric and thermal analysis behaviour

“…As has already been discussed, 8,9 charge repulsion between the aggregates expands the polymer coil dimensions, increasing the reduced viscosity. The effect of the counterion on the PEO±anionic surfactant interaction has also been reported, 34,35 and the results show that sodium dodecyl sulphate interacts more strongly with PEO than with lithium or cupric dodecyl sulphate. This effect is attributed to the af®nity of the counterion for the complexation with the polymer, and in the case of the divalent cupric counterion it is attributed to the larger degree of hydration compared with that of the monovalent Na .…”

Untitled

“…Afterwards, the biological activity of the extract was tested, evaluating the free radical-trapping activity through a DPPH assay (diphenylpicrylhydrazyl, Abuin et al, 2002) in triplicate. For this, 1 mL of the extract was added to 2 mL of DPPH solution (10 mg DPPH (99%) in 1 L of methanol, DPPH 10 mg·L-1), that was later incubated in a thermoregulated bath for 30 min.…”