Other p-Carboline-containing Manzamines

Xestomanzamine A (46) and B (47) were isolated from the Okinawan marine sponge Xestospongia sp. with manzamine X [41], des-N-Methylxestomanzamine A 

Keramaphidin C (50) was isolated from sponge Amphimedon sp. [18]. Haliclorensin (51) was isolated from Halidona sp. and its structure was first proposed as 51 [54]. However, the synthetic ( )-51, (R)- and (S)-51 showed significant differences in NMR and mass spectra from those of natural halicloresin [55]. The structure ofhaliclorensin was revised to (S)-7-methyl-l,5-diazacydo-tetradecane (51a) recently [56]. 

Motuporamines A (52), B (S3), and C (54), which contain a spermidine-like substmcture, represent a new family of cytotoxic sponge alkaloids, were isolated as an inseparable mixture from Xestospongia exigua collected in Papua New Guinea [29]. 

Xestocyclamine A (62) was first isolated from the Papua New Guinea marine sponge Xestospongia (=Acanthostrongylophora) ingens, and its stmcture was revised in the following year vdth the isolation of xestocydamine B (63)[57j. 

Ingenamine G (72) was isolated from Pachychalins sp. collected from Father s Island, Rio de Janerio, Brazil [58] 

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