A plant genus of the family ASCLEPIADACEAE. Members contain steroidal glycosides and cytotoxic phenanthroindolizidine N-oxide alkaloids.

The milkweed plant family of the order Gentianales, subclass Asteridae, class Magnoliopsida. It includes many tropical herbs and shrubby climbers; most with milky juice. Flowers have five united petals. Fruits are podlike, usually with tufted seeds.

Saturated derivatives of the steroid pregnane. The 5-beta series includes PROGESTERONE and related hormones; the 5-alpha series includes forms generally excreted in the urine.

Unsaturated derivatives of PREGNANES.

Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)