Cylindradines A and B: Novel Bromopyrrole Alkaloids from the Marine Sponge <i>Axinella cylindratus</i>

The novel alkaloids cylindradines A and B were isolated from Axinella cylindratus, and their structures were elucidated by spectroscopic analyses. Stereochemistries of these compounds were determined by X-ray analysis. Cylindradines showed moderate inhibitory activity against the murine leukemia cell line P388