HYDROLYSIS OF NONIONIC ESTER SURFACTANTS FACILITATED BY POTASSIUM BETA-GLYCYRRHIZINATE - IMPLICATION OF CATALYTIC FUNCTIONS PLAYED BY THE CARBOXYL GROUPS

Two different types of methyl esters of beta-glycyrrhizinate (GK2) hav e been prepared to delineate the mechanism of the catalytic action of each carboxyl group of GK2 in the hydrolysis of nonionic fatty acid su rfactants. In the acidic pH region of less than 4, the hydrolysis is c atalyzed by the carboxyl groups of the sugar moiety, while in the clos e-to-neutral acidic region, the carboxyl group at the hydrophobic trit erpenoid end becomes important in catalysis.