Avenanthramide D is a phenylamide-type natural product derived from oats, composed of a hydroxycinnamic acid derivative and an anthramide structure. Avenanthramide D exhibits biological activities such as antioxidant and anti-inflammatory effects, and can inhibit the transient receptor potential cation channel subfamily A member 1 (TRPA1) (IC₅₀ = 43 µM), exerting its effects by modulating inflammation-related signaling pathways.