Esters of ferulic acid are found in plant cell walls, covalently bonded to hemicellulose such as arabinoxylans.
The tea brewed from the leaves of yacón (Smallanthus sonchifolius), a plant traditionally grown in the northern and central Andes, contains quantities of ferulic acid.
In wheat grain, ferulic acid is found bound to cell wall polysaccharides, allowing it to be released and absorbed in the small intestine.
[10] Ferulic acid has been identified in Chinese medicine herbs such as Angelica sinensis (female ginseng), Cimicifuga heracleifolia[11] and Ligusticum chuangxiong.
It is also found in the tea brewed from the European centaury (Centaurium erythraea), a plant used as a medical herb in many parts of Europe.
Saccharomyces cerevisiae (dry baker's yeast) and Pseudomonas fluorescens are also able to convert trans-ferulic acid into 2-methoxy-4-vinylphenol.
[21] Ferulic acid is one of the compounds that initiate the vir (virulence) region of Agrobacterium tumefaciens, inducing it to infect plant cells.