[On phenolic acids of vegetables. I. Hydroxycinnamic acids and hydroxybenzoic acids of brassica-species and leaves of other cruciferae (author's transl)].

The contents of phenolic acids in vegetables of the species Brassica almost totally consist of hydroxycinnamic acid compounds. In contrary to other species of vegetables sinapic acid is dominant. Leaves of radish (Rhaphanus sativus var. sativus and var. niger) mainly contain compounds of caffeic and p-coumaric acid; leaves of horse radish show only traces of hydroxycinnamic acids. In the group of hydroxybenzoic acid derivatives traces of salicylic and gentistic acid could be determined in almost all species and frequently vanillic acid. Protocatechnic acid was only identified in red cabbage, especially in the head, syringic acid in gardencress and p-hydroxybenzoic acid in horse radish leaves. No other hydroxybenzoic acids or hydroxycoumarins could be detected.