caffeic acid molecule, structural chemical formula, ball-and-stick model, image hydroxycinnamic acid

caffeic acid hydroxycinnamic molecule molecular structure chemical formula isolated model c9h8o4 atom carbon oxygen chemistry science atomic skeletal antioxidant caffeine organic medicine cancer oil sage substance thyme biosynthesis carcinogenic group research signs metabolism spearmint biomass floral natural plant argan acrylic structural ball- -stick image ball- -stick acid