Studies on the Biosynthesis of Bovilactone‐4,4 and Related Fungal Meroterpenoids

The initial step in the biosynthesis of suillin ( 1 ), boviquinone‐4 ( 2 ) and bovilactone‐4,4 ( 3 ) in Suillus species is the geranylgeranylation of 3,4‐dihydroxybenzoic acid at the 2‐position. Feeding experiments with advanced precursors have identified boviquinone‐4 and deacetylsuillin ( 9 ) as building blocks for the dilactone and catechol moieties, respectively, of bovilactone‐4,4 ( 3 ). In order to explain the failure of boviquinone‐4 ( 2 ) to incorporate side‐chain‐labelled deacetylsuillin ( 9 # ), an alternative sequence for the formation of 2 is proposed. During these experiments an interesting change in metabolism was noticed: after administration of larger quantities of aromatic carboxylic acids, the boviquinone‐4 present in the fruit bodies disappeared and de novo synthesis of bovilactone‐4,4 occurred. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)