Conessine
Conessine is a steroid alkaloid found in a number of plant species from the family Apocynaceae, including Holarrhena floribunda, Holarrhena antidysenterica and Funtumia elastica. It acts as a histamine antagonist, selective for the H3 subtype. It was also found to have long CNS clearance times, high blood-brain barrier penetration and high affinity for the adrenergic receptors.