Hyoscine

An alkaloid found with hyoscyamine (with which it is also isomeric) in henbane, and extracted as a white, amorphous, semisolid substance.

an alkaloid with anticholinergic effects that is used as a sedative and to treat nausea and to dilate the pupils in ophthalmic procedures; "transdermal scopolamine is used to treat motion sickness"; "someone sedated with scopolamine has difficulty lying"