Batzelladines is one fascinating class of a broad family of polycyclic guanidine-derived alkaloids which exclusively are restricted to the marine origin . Chemically, they feature two main fused guanidinic portions linking together via an ester functionality, where a principle tricyclic system named clathriadic acid is assembled to another clathriadic acid or a crambescin bicyclic moiety . Biogenetically, those marine alkaloids are supposed to be generated via sequential modes of cyclization between a polyketide-derived chain and a putative guanidine precursor along with different oxidation degrees to afford such complex metabolites .