Pigments from the Acetate-Malonate Pathway

In contrast to its widespread importance in the biosynthesis of secondary metabolites in Lower Fungi 667, 668) the acetate-malonate pathway is only of restricted importance to pigment production in Macromycetes. It is confined to a few basic systems which are categorised below in line with Turner s classification 667) which is based 

Famesylation has occurred at the alternate site in orsellinic acid during the formation of scutigeral (249) by Albatrellus ovinus and A. subrubescens (98). This compound is responsible for the yellow stain often seen on the sporophores and for the yellow colour reaction of the flesh of these fungi produced with aqueous alkali. The distribution 

Albatrellus species are a rich source of further meroterpenoids 98, 696) and biological screening of the group has revealed remarkable cytotoxic activities (725). 

The taxonomic significance of the occurrence of trametin in Gloeo-phyllum has been assessed chromatographically (92, 180). 

It is interesting that an isomer (254) (fomecin-A) of the tetraketide (253) has been isolated along with the yellow dialdehyde (255) (fomecin-B) from cultures of Antrodia juniperina = Fomes juniperinus) (479). Both fomecins-A and -B have been synthesised (356) and found to exhibit antibiotic properties. 

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