M Coumaric acid

m-Coumaric acid is a hydroxycinnamic acid, an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acids - o-coumaric acid, m-coumaric acid, and p-coumaric acid- that differ by the position of the hydroxy substitution of the phenyl group. m-Coumaric acid can be found in vinegar.