Fungal formation of raspberry ketone differs from the pathway in plant cell culture

Various precursor substances for the biosynthesis of raspberry ketone were applied to the white rot fungus N. niveo-tomentosa to enhance product yield s. L-Phenylalanine, phenyl pyruvate, phenyl propanoic acid, L-tyrosine, 4-h ydroxyphenyl pyruvate, coumaric acid, 4-hydroxyphenyl propanoic acid, benzo ic acid, hippuric acid, benzaldehyde, and 4-hydroxy benzaldehyde showed pre cursor activity, whilst cinnamic acid, phenyl acetic acid, phenyl acetaldeh yde, and 4-hydroxybenzoic acid methyl ester inhibited fungal growth and/or formation of target compounds. Gas chromatography coupled with atomic emiss ion detection (GC-AED) was used to elucidate the biosynthetic pathway to ra spberry ketone after addition of (2)(H) and C-13 isotope labeled L-phenylal anine. Metabolic differences to the biosynthesis proposed for raspberry fru it became evident.