Kleinhospitines A-D, four unprecedented cycloartane triterpenoid alkaloids possessing a spiro α,β-unsaturated γ-lactamlactone side chain, were isolated as two mixtures of C-23 epimers from Kleinhovia hospita. Kleinhospitines C and D represent the first examples of naturally occurring cycloartane
A novel cycloartane triterpenoid alkaloid, kleinhospitine E (1), six new cycloartane triterpenoids (2-7), three known cycloartane triterpenoids (8-10), and taraxerone (11) were isolated from a methanol extract of Kleinhovia hospita. Their structures were elucidated by 1D- and 2D-NMR spectroscopy as