Unprecedented C19-diterpenoid alkaloid glycosides from an aqueous extract of “fu zi”: Neoline 14-O-l-arabinosides with four isomeric l-anabinosyls

Abstract

Four structurally unprecedented aconitane-type C19-diterpenoid alkaloid glycosides with isomeric arabinosyls, named aconicarmichosides A–D (1–4), were isolated from an aqueous extract of “fu zi”, the lateral roots of Aconitum carmichaelii. Their structures were determined as neoline 14-O-α- and 14-O-β-l-arabinopyranosides (1 and 2) and 14-O-α- and 14-O-β-l-arabinofuranosides (3 and 4), by spectroscopic and chemical methods including 2D NMR experiments and acid hydrolysis. Compounds 1–4 represent the first examples of glycosidic diterpenoid alkaloids.