2016 Volume 57 Issue 3 Pages 181-186
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.
