Since deoxypodophyllotoxin and cpipodophyllotoxin are of different origin from those compounds used in our previous work, we confirmed their biological inactivity at 200 mg. per kg. The same inactivity was demonstrated for deoxypicropodophyllin. Introduction of a double bond into the B ring of deoxypicropodophyllin and subsequent formation ofα-,β-, and γ-apopicropodophyllin restore the toxicity and biological effect on the dividing cell. The effect is fivefold less than that of podophyllotoxin. The toxicity-stathmokinesis index of these compounds is lower than 2, so that the compounds are unsuitable for therapeutic use. Complete aromatization of the B ring of dehydroahydropicropodophyllin is again followed by the loss of the biological activity.