13C-NMR assignments and cytotoxicity assessment of zoanthoxanthin alkaloids from zoanthid corals.

Zoanthoxanthin alkaloids can vary among skeletal types A, B, and C. Three type C zoanthoxanthins were examined, including a new compound 1, previously reported paragracine [2], and zoanthoxanthin 3. Their nmr and cytotoxic properties are reported. We have used 2D nmr data to complete the assignments for 1 and suggest that these benchmark nmr assignments will allow future investigators to establish new metabolites of this class as a member of families A, B, or C with only a 13C APT and a 1H-1H nmr spectra.