vincetoxin

from The Century Dictionary.

• noun The name given to two yellow, amorphous, pulverulent compounds, C₁₆H₁₂O₆, contained in powdered asclepias root, Cynanchum Vincitoxicum. They melt at 59° C. One dissolves in water, the other does not.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) A glucoside extracted from the root of the white swallowwort (Vincetoxicum officinale, a plant of the Asclepias family) as a bitter yellow amorphous substance; -- called also asclepiadin, and cynanchin.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun organic chemistry A glucoside extracted from the root of the white swallowwort.