Ma'edamines E and F, rare bromotyrosine alkaloids possessing a 1,2,3,5-tetrasubstituted pyridinium moiety from an Okinawan marine sponge Suberea sp.

Two new bromotyrosine alkaloids, ma'edamines E (1) and F (2), were isolated from an Okinawan marine sponge Suberea sp., and their structures were elucidated by the analyses of spectroscopic (UV, IR, and NMR) and spectrometric (MS) data. Ma'edamines E (1) and F (2) are the second and third examples of natural products possessing an N-alkyl-3,5-diethyl-2-propylpyridinium moiety. Ma'edamine F (2) is the first bromotyrosine alkaloid having both pyridinium and quaternary ammonium moieties. Ma'edamines E (1) and F (2) showed moderate cytotoxicity against L1210 murine leukemia cells in vitro. CO 2022 Elsevier Ltd. All rights reserved.

Automated summary

Two new bromotyrosine alkaloids were isolated from an Okinawan marine sponge Suberea sp., showing moderate cytotoxicity against L1210 murine leukemia cells in vitro.