New ionic compounds containing an alkaloidal cation and a steroidal anion have been isolated by reverse-phase liquid chromatography from the extracts of the starfish Lethasterias nanimensis chelifera. Their structures have been elucidated by NMR and mass spectroscopy as 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinolinium salts of 3-O-sulfoasterone 1, 3-O-sulfoisoasterone 2 and 3-O-sulfothornasterol A 3. In addition, the alkaloid 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) 4 was found in this starfish. (C) 2003 Elsevier Science Ltd. All rights reserved.