MARINE ALKALOIDS .15. 2 ALKALOIDS, FLUSTRAMINE-E AND DEBROMOFLUSTRAMINE-B, FROM THE MARINE BRYOZOAN FLUSTRA-FOLIACEA

A new alkaloid, flustramine E [1], with inhibitory activity towards Rh izotonia solani and Botrytis cinerea was isolated by gas-phase extract ion from the marine bryozoan Flustra foliacea. The structure was deter mined as a,8a-cis-1-methyl-3a-(3-methyl-2-butenyl)-6-bromo- ,2,3,3a,8, 8a-hexahydropyrrolo[2,3-b]indole, based on spectroscopic investigation s. Another alkaloid, debromoflustramine B [2a], was detected in trace amounts and identified by comparison of the mass spectrum with that of a synthetic sample. The extract also contained the previously reporte d alkaloids flustramine A and B in the ratio 1:7.