Modulation of the prenylation step in Anethum graveolens cultured calli. Part II. The role of p-cumaric acid and boropinic acid

Cultured calli from Anethum graveolens L. have been previously shown to biosynthetically manipulate selected precursors having a phenylpropanoid core leading to an increase or a decrease in their prenylation. In this article, an extension of previous studies in this field showing how two other cinnamic acid derivatives, namely p-coumaric acid and boropinic acid, are able to exert similar effects using the same experimental model will be reported. Lyophilized calli from A. graveolens has been powdered and extracted by an overnight maceration with EtOH. Selected oxyprenylated cinnamic acid derivatives were then quantified by HPLC analysis coupled to UV/Vis detection. The effect recorded after administration of p-coumaric acid was similar to that evoked by ferulic acid and consisted in a selective increase of its geranylation. The addition of boropinic acid stimulated the biosynthesis of ferulic acid with longer chain like 4′-farnesyloxyferulic acid. This study demonstrated that administration to cultured calli of phenylpropanoids with no free OH moiety has a deep influence on the prenylation biosynthetic pathways and led to the hypothesis that the elongation of the O-side chain of oxyprenylated cinnamic acid derivatives may occur by addition in sequence of isoprenic units.