MOLECULE

(E)-p-Coumaric acid

trans-4-Coumaric acid or (e)-p-Coumaric acid, the trans-isomer of 4-coumaric acid, also known as 4-hydroxycinnamic acid, belongs to the class of organic compounds known as hydroxycinnamic acids. Hydroxycinnamic acids are compounds containing a cinnamic acid where the benzene ring is hydroxylated. 4-Hydroxycinnamic acid is a neutral compound. 4-Hydroxycinnamic acid exists in all living species, from bacteria to humans. 4-Hydroxycinnamic acid is found in highest concentrations in pepper (c. frutescens), pineapples, and sunflowers and in lower concentration in spinachs, kiwis, and sweet oranges. 4-Hydroxycinnamic acid has also been detected in wild rices, soursops, garden onions, hyssops, and avocado. This could make 4-hydroxycinnamic acid a potential biomarker for the consumption of these foods. 4-Hydroxycinnamic acid is also found in cannabis plants reported by Paris in 1973  (PMID: 6991645).