Digitonin

Digitonin is a steroidal saponin (saraponin) obtained from the foxglove plant "Digitalis purpurea". Its aglycone is digitogenin, a spirostan steroid. It has been investigated as a detergent, as it effectively water-solubilizes lipids. As such, it has several potential membrane-related applications in biochemistry, including solubilizing membrane proteins, precipitating cholesterol, and permeabilizing cell membranes.
Digitonin is sometimes confused with the cardiac drugs digoxin and digitoxin and all three can be extracted from the same source.