(570g) The Location and Interaction Between Propyl Gallate and Nonionic Micelles

Propyl gallate (PG) is widely used in foods, cosmetics and pharmaceuticals. The solubilization of PG in nonionic micelles is few reported. The solubilization of PG in nonionic micelles formed from Genapol^® X-080 (GX-080) and Triton^TM X-100 (TX-100) was investigated by NMR methods. Moreover, association constants (K_a) of PG and the surfactants were calculated by using the first-order reversible fast exchange model. In the presence of PG, the critical micelle concentration (CMC) values of the surfactants decrease. The ¹H NMR and nuclear Overhauser effect (NOE) experiments indicated that PG is solubilized in the shell region of TX-100 micelles, while in GX-080 micelles the aromatic protons of PG interact with the hydrophilic EO chain and more hydrophobic parts penetrate into the micelle core. The values of K_a for GX-100 and TX-080 binding to PG were found to be 700 ± 65 M^-1 and 352 ± 30 M^-1, respectively. The studies on the location and the interaction between antioxidant and surfactants will facilitate the understanding of the mechanism of antioxidant effect and the application of antioxidant in pharmaceutical and cosmetic industry.