A biosynthetic pathway for (E)-methyl cinnamate formation in the ectomycorrhizal fungus Tricholoma matsutake

抄録

A biosynthetic pathway for (E)-methyl cinnamate formation was evaluated in Tricholoma matsutake by tracer experiments using ¹³C- and ²H-labeled precursors. One hundred percent selective ¹³C incorporation was observed when L-[1,2,3,4,5,6,7,8,9-¹³C₉, ^15/N]phenylalanine was converted to (E)-[1,2,3,4,5,6,7,8,9-¹³C₉]cinnamate and (E)-[1,2,3,4,5,6,7,8,9-¹³C₉]methyl cinnamate. Similarly, 100% selective ¹³C incorporation was observed when (E)-[1,2,3,4,5,6,7,8,9-¹³C₉]cinnamate was converted to (E)-[1,2,3,4,5,6,7,8,9-¹³C₉]methyl cinnamate. In contrast, the ²H incorporation selectivities were 82.1% and 81.4% when L-[2,3,4,5,6,7,7,8-²H₈]phenylalanine was converted to (E)-[2,3,4,5,6,7,8-²H₇]cinnamate and (E)-[2,3,4,5,6,7,8-²H₇]methyl cinnamate, respectively. Thus, T. matsutake synthesizes (E)-methyl cinnamate from L-phenylalanine via (E)-cinnamate. (E)-cinnamate was likely formed through two pathways: one was major and the other was a minor.