Arcyria Myxomycete pigments

Fruit bodies of wild myxomycetes often have bright colors. In 1980 Steglich et al. isolated red and yellow pigments from methanol extracts of 2 g of the red fruit bodies of Arcyria denudata [7], Structure of these pigments were elucidated by spectral data as a series of bisindole maleimides, and they were named arcyriarubin B (1), C (2), arcyriaflavin B (3), C (4), and arcyrioxepin A (5). 1, 2, and 5 were red... 

Several other examples of indole pigments with bisindolylmaleimide structures have been isolated from the slime mold Arcyria denudata (Tri-chiales, Myxomycetes, Myxomycota). The chemistry and physical... 

Arcyria pigments (bisindolylmaleimides and in-dolo[2,3-a]carbazoles). The tiny fruit bodies of the slime molds Arcyria denudata, A. nutans, and related myxomycetes contain indole pigments of the bisindol-ylmaleinimide type. Parent compounds are the red ar-cyriarubins A, B, and C. Oxidative cyclization in the 2,2 -position furnishes the pale yellow and poorly soluble arcyriaflavins A, B, and C (table I). Indolocarba-zoles of this type are also known as active principles from streptomycetes ( rebeccamycin). 

The red spc rangia of the slime mould Arcyria denudata contain a number of unique indole pigments (156,157,623). By careful chromatography of the methanolic extract of this and related myxomycetes the pigments (500)-(513) have been isolated and characterised. Some physical properties of this new group of natural pigments, for which we propose the collective name bisindolylmaleimides, are given in Table 48. 

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