Fused ring alkaloids having the pyridol[4,3,2-mn]acridine skeleton comprise a new class of marine natural products.1a-h Their biological activity1e and challenging structure elucidation make them an interesting group of compounds. In this paper we report the identification of four new cytotoxic and structurally related alkaloids: nordercitin (1), dercitamine (2), dercitamide (3), and cyclodercitin (4). © 1989.