Pandalisines A and B, novel indolizidine alkaloids from the leaves of Pandanus utilis.

Two novel alkaloids named pandalisines A (1) and B (2), constituting a new class of C8-substituted indolizidine moiety, were isolated from the leaves of Pandanus utilis. The structures of these new compounds were established by their mass and spectroscopic data. The absolute configuration was determined by the comparison of experimental CD and calculated ECD spectra. A plausible biosynthetic pathway for compounds 1 and 2 is advanced. The cytotoxic activities of the isolated alkaloids against A-549, Hep-G2, and MDA-MB-231 cancer cell lines were evaluated. The result showed that 1 and 2 are the first non-cytotoxic indolizidine alkaloids.