The North American stalked puffball Calostoma cinnabarinum (Boletales) owes its red-orange colour to the heptaene pigment calostomal. Its structure has been determined by 1H and 13C NMR spectroscopy of the corresponding methyl ester as all-trans-16-oxohexadeca-2,4,6,8,10,12,14- heptaenoic acid (1). Neither pulvinic acids nor other typical Boletales pigments could be detected in this fungus. The structural relationship of 1 to other polyene pigments from fungi is discussed.
Zeitschrift für Naturforschung B is an international scientific journal which publishes original papers, microreviews, and letters from all areas of inorganic chemistry, solid state chemistry, coordination chemistry, molecular chemistry, and organic chemistry.