Studies on veratrum alkaloids. XIV. The antiaccelerator cardiac action of derivatives of veratramine and jervine and of synthetic steroid secondary alkamines obtained from pregnenolone and from sapogenins.

Dihydroveratramine, tetrahydrojervine and Δ4-jervone, have been quantitatively compared with veratramine and jervine in regard to their antiaccelerator cardiac activity. The experiments were carried out using the heart-lung preparation of the dog under standard conditions of cardioacceleration caused by the continuous infusion of synthetic l -epinephrine. A substance obtained by partial synthesis from pregnenolone, 20-(5'-methyl-2'-piperidyl)-Δ5-pregnen-3β, 20-diol, and kryptogenamine, prepared by partial synthesis from kryptogenin, have been shown to exhibit the characteristic antiaccelerator cardiac activity and have been included in the quantitative study. The antiaccelerator cardiac activity decreases in the following order: veratramine > dihydroveratramine > tetrahydrojervine > 20-(5'-methyl-2'-piperidyl)-Δ5-pregnen-3β, 20-diol, jervine, Δ4-jervone > kryptogenamine. Three types of steroid secondary amines exhibiting antiaccelerator cardiac activity, namely piperidine, pyrrolidine, and spiroaminoketal derivatives, have been considered. All of the substances characterized by high antiaccelerator potency are of the piperidine type.