What is "conessine"

Wrightine \Wright"ine\, n. (Chem.) A rare alkaloid found in the bark of an East Indian apocynaceous tree ( Wrightia antidysenterica), and extracted as a bitter white crystalline substance. It was formerly used as a remedy for diarrh[oe]a. Called also conessine, and neriine.

n. A steroid alkaloid found in a number of plant species of the Apocynaceae family, sometimes used in herbal medicine as a treatment for amoebic dysentery.

Conessine is a steroid alkaloid found in a number of plant species from the Apocynaceae family, including Holarrhena floribunda, Holarrhena antidysenterica and Funtumia elastica. It acts as a histamine antagonist, selective for the H subtype (with an affinity of pK = 8.27; K = ~5 nM). It was also found to have long CNS clearance times, high blood-brain barrier penetration and high affinity for the adrenergic receptors.