p-Coumaric Acid

4-hydroxycinnamic acid Phenolic acid (hydroxycinnamate)

Function

p-Coumaric acid is a hydroxycinnamic acid phytochemical found in tomatoes, peanuts, carrots, garlic, onions, whole grains, berries, and numerous fruits and vegetables. It is widely distributed in plant tissues where it contributes to structural integrity, defense responses, and phenolic metabolism.

p-Coumaric acid functions mainly as a phenolic antioxidant involved in oxidative stress interactions, inflammatory signaling modulation, and plant cell wall chemistry. Research has examined its effects on antioxidant pathways, endothelial signaling, reactive oxygen species balance, and inflammatory mediators.

It serves as an important intermediate in the biosynthesis of flavonoids, lignins, and additional phenolic compounds within plants.

Production

Plants synthesize p-coumaric acid through phenylpropanoid biosynthesis pathways beginning with phenylalanine metabolism. Phenylalanine ammonia-lyase and related enzymes convert aromatic amino acid precursors into cinnamic acid derivatives including p-coumaric acid.

The compound contributes to lignin formation and cross-linking within plant cell walls. Environmental stress, ultraviolet exposure, and developmental stage influence accumulation.

After ingestion, p-coumaric acid undergoes intestinal absorption, microbial metabolism, conjugation, and transformation into additional phenolic metabolites.

Regulation

p-Coumaric acid activity is regulated by food matrix interactions, microbiome metabolism, absorption efficiency, and conjugation pathways. Whole grain and vegetable fiber structures can influence release during digestion.

Research suggests p-coumaric acid may interact with oxidative stress pathways, inflammatory mediators, endothelial responses, and antioxidant systems. Effects depend on tissue exposure and downstream metabolism.

Consumption from grains, vegetables, fruits, and nuts provides p-coumaric acid together with flavonoids, fiber, minerals, and additional phenolic acids that collectively support antioxidant and cellular signaling diversity.

Chemical Identity

Molecular Formula: C9H8O3
Molar Mass: 164.160 g/mol

Key Biological Functions

  • Antioxidant; supports endothelial function (diet context).

Key Foods / Plant Sources

Top Foods
  • Tomatoes; carrots; garlic; whole grains
Additional Sources
  • Common in plant cell walls and peels.

Bioavailability & Inhibitors

Inhibitor / Factor Effect on Activity / Absorption
Heat stable; bound forms released by digestion/microbiota.
Note: Factors relate to activation and cellular signaling context. Educational only.

Cellular Pathways Involved

  • NO/endothelial and redox pathways (diet context).

Low Intake / Context

  • No classical deficiency.

Linked Cancers

  • Vascular health (diet pattern)

Linked Ailments / Conditions

  • Oxidative stress

SUMMARY OF EFFECTS ON THE BODY

  • Immune: antioxidant
  • Cardiovascular: NO tone
  • Digestive: bound-phenolic release
  • Skin: microvascular stability
  • Cellular: oxidative balance