Ferulic acid

Ferulic acid is a hydroxycinnamic acid, an organic compound. It is an abundant phenolic phytochemical found in plant cell walls, covalently bonded as side chains to molecules such as arabinoxylans. As a component of lignin, ferulic acid is a precursor in the manufacture of other aromatic compounds. The name is derived from the genus Ferula, referring to the giant fennel (Ferula communis). Ferulic acid is a hydroxycinnamic acid, an organic compound. It is an abundant phenolic phytochemical found in plant cell walls, covalently bonded as side chains to molecules such as arabinoxylans. As a component of lignin, ferulic acid is a precursor in the manufacture of other aromatic compounds. The name is derived from the genus Ferula, referring to the giant fennel (Ferula communis). As a building block of lignocelluloses, such as pectin and lignin, ferulic acid is ubiquitous in the plant kingdom. Ferulic acid is found in a number of vegetable sources, and occurs in particularly high concentrations in popcorn and bamboo shoots. It is a major metabolite of chlorogenic acids in humans along with caffeic and isoferulic acid, and is absorbed in the small intestine, whereas other metabolites such as dihydroferulic acid, feruloylglycine and dihydroferulic acid sulfate are produced from chlorogenic acid in the large intestine by the action of gut flora. In cereals, ferulic acid is localized in the bran – the hard outer layer of grain. In wheat, phenolic compounds are mainly found in the form of insoluble bound ferulic acid and may be relevant to resistance to wheat fungal diseases. The highest known concentration of ferulic acid glucoside has been found in flaxseed (4.1 ± 0.2 g/kg). It is also found in barley grain. Asterid eudicot plants can also produce ferulic acid. 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 legumes, the white bean variety navy bean is the richest source of ferulic acid among the common bean (Phaseolus vulgaris) varieties. It is also found in horse grams (Macrotyloma uniflorum). Although there are many sources of ferulic acid in nature, its bioavailability depends on the form in which it is present: free ferulic acid has limited solubility in water, and hence poor bioavailability. In wheat grain, ferulic acid is found bound to cell wall polysaccharides, allowing it to be released and absorbed in the small intestine. Ferulic acid has been identified in Chinese medicine herbs such as Angelica sinensis (female ginseng), Cimicifuga heracleifolia 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. Cooked sweetcorn releases increased levels of ferulic acid. As plant sterol esters, this compound is naturally found in rice bran oil, a popular cooking oil in several Asian countries. Ferulic acid glucoside can be found in commercial breads containing flaxseed. Rye bread contains ferulic acid dehydrodimers.