Reactivity of Bio-Related Molecules with Active Oxygen Species Determined by the Sonochemical Luminescence Method

Abstract

Reactivities of bio-related molecules with active oxygen species were measured by the sonochemical luminescent (SCL) method proposed in our previous paper. Sixteen kinds of amino acids, four kinds of nucleobase-model compounds and α-tocopherol as a typical antioxidant compound were measured by the method. Among the amino acids, L-tyrosine, L(–)-phenylalanine, L-tryptophane, L(–)-cystine were found to be more reactive than the others. Among the nucleobase-model compounds, purine bases exhibited higher reactivity than pyrimidine ones. α-Tocopherol was examined while dissolving it as the micellar solution because of its low solubility in water. To evaluate the reactivity of α-tocopherol itself, the reactivities of surfactants used to prepare micellar solution were also measured, and cetyltrimethylammonium bromide was found not so reactive as obstructing the measurement of α-tocopherol’s reactivity. The experiments in the micellar solution showed high reactivity of α-tocopherol. On the basis of these results, application of the proposed method to the evaluation of antioxidant reactivity was discussed.