Pseudoceratina ceratamines

A Papua New Guinea sponge, Pseudoceratina sp., contains the unusual alkaloids ceratamines A (1142) and B (1143), and a biogenesis involving histidine and tyrosine is proposed (1173). The fermentation broth from Aspergillus fischeri var. thermomutatus has yielded CJ-12662 (1144) and UK-88051 (1145) (1174). The former metabolite was confirmed by X-ray spectroscopy and partial synthesis. A marine-derived Streptomyces sp. produces the novel pyrrolizidine 5-chlorobohem-amine C (1146), which was shown not to be an isolation artifact (1175). The Chinese medicinal plant Huperzia serrata has furnished 2-chlorohyperzine E (1147) (1176). 

Manzo E, van Soest R, Matainaho L, Roberge M, Andersen RJ (2003) Ceratamines A and B, Antimitotic Heterocyclic Alkaloids Isolated from the Marine Sponge Pseudoceratina sp. Collected in Papua New Guinea. Org Lett 5 4591... 

Most probably formed from 3,5-dibromotyrosine and histidine, ceratamines A and B are antimitotics isolated from an imdetermined species of the genus Pseudoceratina harvested in Papua New Guinea (Manzo et al, 2003). 

Manzo, E., Van SoesL R.W.M., Matainaho, L., Roherge, M., and Andersen, R.J. (2003) Ceratamines A and B, antimitotic heterocydic alkaloids isolated from the marine sponge Pseudoceratina sp. collected in Papua New Guinea Org. Lett., 5, 4591 594. 

The obvious biogenetic relationship of ceratamines A and B to 5-bromoverog-amine (138) (100), also isolated from a Pseudoceratina sp., and ianthelline (137) (99) supports the proposed structures 249 and 250. The putative biogenetic precursors to these alkaloids are histidine and tyrosine as shown. 

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