Scocycamides, a Pair of Macrocyclic Dicaffeoylspermidines with Butyrylcholinesterase Inhibition and Antioxidation Activity from the Roots of Scopolia tangutica

A pair of new macrocyclic spermidine alkaloids, (+)-( S )-scocycamide and (−)-( R )-scocycamide, were isolated from the roots of Scopolia tangutica . Their structures were established by extensive spectroscopic data, electronic circular dichroism analyses, and chemical synthesis. They featured a unique 6/18 fused bicyclic framework with spermidine and catechol units, representing a new subtype of natural spermidine alkaloids. A plausible biosynthetic pathway was also proposed. They inhibited butyrylcholinesterase and exhibited antioxidant capacity, suggesting beneficial constituents against Alzheimer’s disease and oxidation.