METABOLISM AND NONABSORPTION OF SOYBEAN HYPOCOTYL SAPONINS IN THE RATMODEL

Soybean saponins are soybean glycosides of which new soybean saponins, containing the 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDM P) moiety have recently been detected. Soybean saponins which lost thi s moiety have already been found to posses physiological functions. Th e new saponins, called DDMP-saponins, are also expected to exhibit phy siological characteristics. However, no digestive experiments for DDMP -saponins or non-DDMP-saponins have been conducted until this study. T herefore, trials have been carried out using rats fed on soybean hypoc olyl diets which contain significant quantities of saponins. As a resu lt of analyses using HPLC and TLC, it was found that no saponins were present in urine, in blood nor in liver. However, aglycones, non-DDMP- saponins and small amounts of DDMP-saponins were detected in faeces. T hese results indicated that soybean saponins are not absorbed in alime ntary canal of the rats but rather are hydrolyzed into aglycones.