ISOLATION OF A URINARY DIGITALIS-LIKE FACTOR INDISTINGUISHABLE FROM DIGOXIN

A digitalis-like factor has been purified to apparent homogeneity from human urine based on the inhibitory effect on [3H]ouabain binding to intact human erythrocytes. The purification scheme involved large scale adsorption followed by preparative, semipreparative and analytical high-perormance liquid chromatography. The purified material showed a prominent digoxin-like immunoreactivity. The behaviour of the isolated substance was identical to that of authentic digoxin is three high-performance liquid chromatography and three thin-layer chromatography systems. Moreover, fast atom bombardment mass spectrum and proton nuclear magnetic resonance spectrum suggested that the purified material may be indistinguishable from digoxin. © 1990 Academic Press, Inc.