Fruit bodies of Cyttaria johowii which were often consumed by Amerindians were investigated for their secondary metabolites. Nine different sterols and sterones with the ergostane skeleton were found. The main components were dihydrobrassicasterol, ergost-4-en-3-one and (24S)-3β-hydroxyergost-5-en-6-one. Since for the closely related (24R)-3β-hydroxyergost-5-en-6-one cytostatic activity was reported and cytotoxic polysaccharides were already found in Cyttaria spp., the ethnopharmacological implications are briefly discussed
