Bufadienolide

Bufadienolide is a chemical compound with steroid structure. Its derivatives are collectively known as bufadienolides, including many in the form of bufadienolide glycosides (bufadienolides that contain structural groups derived from sugars). These are a type of cardiac glycoside, the other being the cardenolide glycosides. Both bufadienolides and their glycosides are toxic; specifically, they can cause an atrioventricular block, bradycardia (slow heartbeat), ventricular tachycardia (a type of rapid heartbeat), and possibly lethal cardiac arrest.
Etymology.
The term derives from the toad genus "Bufo" that contains bufadienolide glycosides, the suffix "-adien-" that refers to the two double bonds in the lactone ring, and the ending "-olide" that denotes the lactone structure. Consequently, related structures with only one double bond are called "bufenolides", and the saturated equivalent is "bufanolide".
Classification.
According to MeSH, bufadienolides and bufanolides are classified as follows: