The sponge Mycale micracanthoxea contains fourteen new compounds: a series of twelve 5acyl-2-hydroxymethylpyrroles, named mycalazols 1-12 (1-12), together with two 5-alkylpyrrole-2carbaldehydes, mycalazal 1 (13) and mycalazal 2 (14). The structures were elucidated by interpretation of spectral data. In general, the new compounds showed significant in vitro cytotoxicity. Copyright © 1996 Elsevier Science Ltd