SOYBEAN SAPONINS - FATE OF INGESTED SOYBEAN SAPONINS AND PHYSIOLOGICAL ASPECT OF THEIR HEMOLYTIC ACTIVITY

Biological properties of soybean saponins were studied on chicks, rats, and mice kept on soybean saponin -containing diets. Neither soybean saponins nor soybean sapogenins could be found in the blood of these organisms. Ingested soybean saponins were hydrolyzed into sapogenins and sugars by the cecal microflora of chicks, rats, and mice. Saponin-hydrolyzing enzyme(s) from the cecal microflora of rats was partially purified by successive column chromatography on DEAE-cellulose and Ca phosphate (hydroxyl apatite) in the presence of 2-mercaptoethanol. The optimal activity of the crude enzyme(s) was at pH 6.5; of the purified preparation, at pH 6.1. It has shown a low degree of specificity, indicated by the numerous glycosides, including alfalfa saponins, that it hydrolyzes. The in vitro hemolytic activity of soybean saponins on red blood cells was fully inhibited in the presence of plasma or its constituents. © 1968, American Chemical Society. All rights reserved.