Secondary glycoside from Digitalis purpurea L., Scrophulariaceae. Extracted from the dried leaves with 50% alc. Extraction procedure: Cloetta, Arch. Exp. Pathol. Pharmakol. 112, 261 (1926). Purification: Windaus, Freese, Ber. 58, 2503 (1925). Ten kilo leaves yield about 6 grams pure digitoxin. Identity with digitophyllin: Cloetta, Arch. Exp. Pathol. Pharmakol. 88, 113 (1920). Structure: See reviews by Elderfield in Chem. Rev. 17, 187 (1935), and Stoll, The Cardiac Glycosides (London, 1937); also Shoppee in Annu. Rev. Biochem. 11, 103 (1942). Acid hydrolysis yields 1 mol digitoxigenin + 3 mol digitoxose. The sugar residue is attached to the hydroxyl group at C-3 of the aglycon. Structure of the sugar moiety: Lichti et al., Helv. Chim. Acta 45, 868 (1962). Digitoxin U.S.P. is either pure digitoxin or a mixture of cardioactive glycosides obtained from Digitalis purpurea and consisting chiefly of digitoxin. The potency of digitoxin U.S.P. corresp to the potency of an equal wt of U.S.P. Digitoxin Reference Standard. A deviation of 20% is permitted. The physical characteristics given below are those of the pure compd. Toxicity data: Foerster et al., Arch. Int. Pharmacodyn. Ther. 159, 1 (1966). Comprehensive description: I. M. Jakovljevic, Anal. Profiles Drug Subs. 3, 149-172 (1974).
Cardiotonic.
Cardiotonic