<jats:title>Abstract</jats:title><jats:p>Two previously unknown red alkaloid pigments, mycenarubin A (<jats:bold>1</jats:bold>), and a dimer thereof, mycenarubin B (<jats:bold>6</jats:bold>), have been isolated from fruiting bodies of <jats:italic>Mycena rosea</jats:italic> and the structures of these pyrroloquinoline alkaloids have been established by 2D NMR and ESI‐MS methods. Their absoluteconfigurations were determined by comparison of their CD spectra with the CD spectrum of a synthetic model compound. The fungal pigments are structurally related to the damirones, isolated from a marine sponge, and may be biosynthetically derived from tryptophan and <jats:italic>S</jats:italic>‐adenosylmethionine.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)