Isoferulic acid is a hydroxycinnamic acid, a type of organic compound. It is an isomer of ferulic acid. Isoferulic acid is a hydroxycinnamic acid, a type of organic compound. It is an isomer of ferulic acid. Isoferulic acid can be found, amongst other compounds, in Lobelia chinensis. An analysis of propolis from Henan, China found sinapinic acid, isoferulic acid, caffeic acid and chrysin, with the first three compounds demonstrating antibacterial properties. Ferulic acid is found in pineapple flesh.