Biosynthesis of blazeispirol A, an unprecedented skeleton from the cultured mycelia of the fungus Agaricus blazei

The biosynthesis of blazeispirol A, an unprecedented skeleton, was investig ated by feeding C-13-labeled acetates, propionate and methionine, to the gr owing cultures of Agaricus blazei (Agaricaceae). C-13 NMR spectral analysis demonstrated the mevalonate origin of the spiroacetal moiety and the dihyd ronaphthalene moiety. The O-methyl and 28-methyl groups of blazeispirol A w ere labeled by feeding L-[methyl-C-13] methionine. The biosynthetic origin of blazeispirol A derived from ergosterol is discussed. (C) 2000 Elsevier S cience Ltd. All rights reserved.