Figure 4.

GC-MS analysis of benzenoid and phenylpropanoid compounds produced by petunia petal tissue fed with Phe and ²H₅-Phe for 4 h. The panel for each presented compound contains mass spectrum of authentic compound standard, mass spectrum of compound extracted from Phe-fed tissue (unlabeled), and mass spectrum representing a combination of unlabeled and labeled compound extracted from ²H₅-Phe fed petal tissue (d₅-labeled). All newly synthesized labeled benzenoid compounds exhibit a mass shift by 5 amu, except eugenol and isoeugenol, which exhibit a shift of only by 3 amu.