Methyl p-coumarate (Methyl 4-hydroxycinnamate), an esterified derivative of p-Coumaric acid (pCA), is isolated from the flower of Trixis michuacana var longifolia.Methyl p-coumarate could inhibit the melanin formation in B16 mouse melanoma cells. Methyl p-coumarate also has strong in vitro inhibitory effect on A. alternata and other pathogens.