Ipvelutine, 7β-Acetoxy-2α-(tigloyloxy)tropane, an Unusual Tropane Alkaloid from Ipomoea velutina R. Br. (Convolvulaceae)

Abstract

Convolvulaceae provide a rich source of tropane alkaloids, however, 2-substituted tropanes have been described for only few species of this taxon. In this note, 2,7-diesters such as ipvelutine [7β-acetoxy-2α-(tigloyloxy)tropane] isolated from the vegetative parts of the Australian Ipomoea velutina R. BR. are described as a new group of tropane diesters.

Synthesis of Aza-Bridged Perhydroazulene Chimeras of Tropanes and Hederacine A

“…Historically, the most notorious member of the tropane alkaloid family is cocaine 1 , a banned substance because of its highly addictive properties (Figure ). Intriguingly, the 8-azabicyclo[3.2.1]­octane core structure found in cocaine 1 is found in dihydroxytropane natural products, isolated in the form of mono- and diesters such as vaccinine B 2 , valeroidine 6 , , merredissine 7 , , or pervilleine B/C/F 3 – 5 , ,, which display promising multidrug resistant inhibitory activities. − Other natural products from the nor tropane family characterized by a secondary nitrogen atom are also known, such as ipvelutine 10 or (−)-Bao Gong Teng A 8 and (−)-erycibelline 9 , for which diverse biological activities have been reported (Figure ). , Of considerable interest was the prospect of using of Bao Gong Teng A as an antiglaucoma compound .…”