METABOLISM OF PUERARIN AND DAIDZIN BY HUMAN INTESTINAL BACTERIA AND THEIR RELATION TO IN-VITRO CYTOTOXICITY

When puerarin or daidzin were incubated far 24 h with human intestinal bacteria, two metabolites, daidzein and calycosin, were produced from them, respectively. The metabolic time course of puerarin was as foll ows: at an early time, puerarin was converted to daidzin, and then cal ycosin. The metabolic time course of daidzin by human intestinal bacte ria was also similar to that of puerarin. The in vitro cytotoxicities of these metabolites, calycosin and daidzein, mere superior to those o f puerarin and daidzein.