Modulation of the biosynthesis of oxyprenylated coumarins in calli from Ferulago campestris elicited by ferulic acid

Previous and recent literature acquisitions suggested that cultured calli are an efficient and meaningful model to investigate the extent and fate of prenylation of phenylpropanoid cores in plants belonging to the Rutaceae and Apiaceae families upon administration of putative biosynthetic precursors. To this concern, in the present manuscript, we investigated the effect of supplementation of ferulic acid and umbelliferone on the biosynthesis of their oxyprenylated counterparts in Ferulago campestris (Besser) Grecescu (Fam. Apiaceae) cultured calli. Dried plant biomass material has been extracted by an ultrasoundassisted extraction with EtOH. O-prenyl secondary metabolites, namely 3,3-dimethylallyloxy, geranyloxy, and farnesyloxy derivatives of both ferulic acid and umbelliferone, were identified and quantified by HPLC/DAD analyses. Supplementation with ferulic acid was the only treatment providing appreciable results. Quite surprisingly, its addition to cultured calli did not affect the formation of its oxyprenylated phytochemicals but boosted the biosynthesis of umbelliferone and its farnesyloxyderivative umbrelliprenin. The findings reported herein enforce and underline the role of ferulic acid as an elicitor of selected classes of secondary metabolites in apiaceous species, as recently observed. In addition to these results, a novel hitherto unknown metabolite from F. campestris, namely 7-[[(2E)-7-hydroxy-3,7-dimethyl-2-octen-1-yl]oxy]-2H-1-benzopyran- 2-one, was characterized by NMR and LC–MS analyses.