DIGITALIS III: THE RELATIONSHIP BETWEEN THE POTENCY AND BALJET REACTION OF THE GLYCOSIDES OF DIGITALIS

1. The relative intensities of the color reaction of solutions of seven digitalis glycosides toward alkaline picrate solutions have been determined. These glycosides are lanatosides A, B, and C, digoxin, digitoxin, gitoxin, and gitalin. 2. Confirming earlier work, the color intensities produced by the purpurea glycosides parallel the cardiotonic activity. This relationship does not hold in the case of the lanata glycosides and therefore, mixtures of these glycosides cannot be assayed by this color intensity. 3. An explanation has been offered to account for the differences in reactivity among the purpurea glycosides and digoxin based upon the supposition of the formation of isomers which are inactive. On the same basis, an explanation has been given for the observed divergence from Beer9s law of the Baljet color reaction with these glycosides.