The Collaborative International Dictionary
Convolvulin
Convolvulin \Con*vol"vu*lin\, n. (Chem.) A glucoside occurring in jalap (the root of a convolvulaceous plant), and extracted as a colorless, tasteless, gummy mass of powerful purgative properties.
Wiktionary
convolvulin
n. (context organic compound English) A glucoside occurring in jalap (the root of a convolvulaceous plant), used as a purgative.