Incubation of pentaacetylgitoxin (I) with liver and heart homogenates of rabbits easily caused the fission of acetyl groups in the terminal sugar moiety and gave 3', 3", 16-triacetylgitoxin (IIc) as a main product, respectively, accompanied with small quantities of several partial acetates and gitoxin (IIj). IIc was the intermediate in hydrolysis of I to IIj with dilute alkali.
