1.(Medicine, Pharmacy) Any one of several extracts of foxglove (Digitalis), as the "French extract," the "German extract," etc., which differ among themselves in composition and properties. Both Digitalis lanata and Digitalis purpurea have been used to prepare such extracts.
2.(Chem.) The distinctive chemical substance, a steroid glycoside, which is the essential ingredient of the extracts of foxglove. It is a white, crystalline substance (C36H56O14), and is a 3-substituted diglucoside of a steroid. It is a powerful cardiac stimulant and is used as a cardiotonic for treatment of certain heart conditions, such as congestive heart failure. Chemically it is (3 beta,5 beta,16 beta)-3-(6-Deoxy-4-O-beta-D-glucopyranosyl-3-O-methyl-beta-D-galactopyranosyl)oxy)-14,16-dihyroxy-card-20(22)-enolide. The related compounds digitoxin and digoxin are also extracted from the foxglove. The class of steroid glycosides having cardiotonic properties are refered to as the cardiac glycosides.
