Damipipecolin and damituricin, novel bioactive bromopyrrole alkaloids from the Mediterranean sponge Axinella damicornis

Abstract: Two new bromopyrrole alkaloids, damipipecolin (1) and damituricin (2), have been isolated from the Mediterranean sponge Axinella damicornis, and their structures established through spectroscopic methods. Compounds 1 and 2 extend the structural variety of the so far known pyrrole alkaloids; in these compounds, the 4-bromopyrrole 2-carboxylic acid is directly condensed with a non-protein cyclic α-amino acid, the (2R, 4R)-trans-4-hydroxypipecolic acid and (2R, 4R)-cis-N,N′-dimethyl-4-hydroxyproline (d-turicine) in 1 and 2, respectively. Compounds 1 and 2 were found to display a modulating effect of the serotonin receptor activity in vitro. [Copyright &y& Elsevier]