Cyclohaliclonamines A-E: Dimeric, Trimeric, Tetrameric, Pentameric, and Hexameric 3-Alkyl Pyridinium Alkaloids from a Marine Sponge Haliclona sp

摘要

A mixture of cyclohaliclonamines A-E (1-5), novel dimeric, trimeric, tetrameric, pentameric, and hexameric 3-alkylpyridinium alkaloids, was obtained from an Okinawan sponge Haliclona sp. Cyclohaliclonamines C-E are the first tetrameric, pentameric, and hexameric 3-alkylpyridinium alkaloids from natural sources. The structure determination of cyclohaliclonamines is discussed in detail.