Physovenines: Efficient Synthesis of (−)- and (+)-Physovenine and Synthesis of Carbarnate Analogues of (−)-Physovenine. Anticholinesterase Activity and Analgesic Properties of Optically Active Physovenines

Column chromatography of easy available (±)-physovenine ( 2 ) on cellulose triacetate afforded (?)- and (+)-physovenine ( 2a and 2b , resp.). Alkaloids 2a , b required for pharmacological testing were prepared from eserolincs ( 3a , b ) by an improved procedure. Natural (?)-physovenine ( 2a ) was equally potent in inhibiting AChE and BChE in vitro as natural physostigmine (1a), and twice as potent as the unnatural antipode 2b against AChE and 14 times as potent against BChE. Several carbamate analogs of 2a were at least as potent as the former compound in these assays. None of the compounds tested did bind to different opiate receptor or serotonine receptor preparations. Most of the compounds tested had considerable analgesic activity in the Writhing test.