Thiocardenolides I: synthesis and biological actions of 3beta-thiocyanato-14beta-hydroxy-5beta-card-20(22)-enolide.

The synthesis of a 3beta-thiocyanatocardenolide is described. The compound exhibited about 0.1 times the cardiotonic effect of digitoxyigenin in the isolated frog heart preparation. At a dosage of 20 mg/kg in the intact rat, it elicited ECG changes similar to those seen with a 10-mg/kg dose of digitoxigenin. Studies also revealed the new cardenolide to be a reversible inhibitor of sodium- and potassium-activated adenosine triphosphatase.