Birnbaumin A and B: Two unusual 1-hydroxyindole pigments from the "Flower Pot Parasol" Leucocoprinus birnbaumii

Abstract

(Figure Presented) It can come as a surprise to plant lovers to find the fruit bodies of Leucocoprinus birnbaumii (see picture) in their flower pots. This fragile fungus, which is harmless to plants, owes its yellow color to the unusual alkaloids birnbaumin A and B, in which a "1-hydroxyindole-3- glyoxylic acid amide is attached through a tetramethylene unit to N-hydroxyoxamidine. N-Hydroxyoxamidines have not been described previously. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.