Platisidines A-C, N-Methylpyridinium Alkaloids from an Okinawan Marine Sponge of Plakortis Species

Platisidines A-C, N-Methylpyridinium Alkaloids from an Okinawan Marine Sponge of Plakortis Species Novel marine sponge alkaloids. 1. Plakinidine A and B, anthelmintic active alkaloids from a Plakortis sponge Novel marine sponge alkaloids. 1. Plakinidine A and B, anthelmintic active alkaloids from a Plakortis sponge Plakoridine C, a novel piperidine alkaloid from an Okinawan marine sponge Plakortis sp. Niphatesines E–H, new pyridine alkaloids from the Okinawan marine sponge Niphates sp. Niphatesines E–H, new pyridine alkaloids from the Okinawan marine sponge Niphates sp. Plakinidines: Cytotoxic alkaloid pigments from the fijian sponge plakortis sp. Echinoclathrines A–C: A new class of pyridine alkaloids from an Okinawan sponge, Echinoclathria sp. Isolation of Plakinamine I: A New Steroidal Alkaloid from the Marine Sponge Corticium sp. and Synthesis of an Analogue Model Compound New Pyridinium Alkaloids from a Marine Sponge of the GenusSpongiawith a Human Phospholipase A₂Inhibitor Profile