Identification of the constituents of balsam of Peru in tomatoes

Background: Studies show that balsam-restricted diets result in significant improvement of systemic contact dermatitis in patients with contact allergy to balsam of Peru (BOP). While tomatoes have been implicated as a frequent cause of BOP-related dermatitis, the presence of BOP in tomatoes has never been confirmed. Objectives: High-performance liquid chromatography coupled with mass spectrometry (liquid chromatography [LC]-MS) and UV spectrometry (LC-UV) was used to detect the possible presence of BOP constituents in tomatoes. Methods: Samples of beefsteak, cherry, and plum tomatoes were extracted in ethyl acetate and analyzed with LC-MS and LC-UV for the presence of the following sensitizing constituents of BOP: benzoic acid, benzyl alcohol, trans-cinnamic acid, cinnamic alcohol, cinnamyl cinnamate, coniferyl alcohol, eugenol, isoeugenol, and methyl cinnamate. Results: The initial LC-MS analysis of each tomato extract showed multiple peaks. Two of these peaks had molecular weights of 134 and 180, which correspond to cinnamic alcohol and coniferyl alcohol, respectively. The analysis did not show peaks corresponding to the molecular weights of the remaining compounds. Cochromatography of tomato extract with cinnamic alcohol and coniferyl alcohol using LC-UV further suggested the presence of these compounds in the tomato extract. Conclusion: Coniferyl alcohol and cinnamic alcohol, constituents of BOP, are present in beefsteak, cherry, and plum tomatoes.