Different from acetate polymalonic route, the mixed shikimate acetate pathway is the biosynthesis method applied to xanthones produced in higher plants. In the biosynthesis mechanism of this mixed shikimate acetate pathway, a phenylalanine, which is formed from shikimate by losing two carbon atoms from the side chain, is oxidized to form an m-hydroxybenzoic acid. This m-hydroxybenzoic acid is then combined with three units of acetate (via malonate) to produce the shikimate-acetate intermediate. Suitable folding and ring closure of this intermediate will give a substituted benzophenone, which generates a central ring of xanthone moiety by an oxidative phenol coupling reaction. The other mechanisms for the intramolecular reaction of benzophenone involve quinine addition and dehydration between hydroxyl groups on acetate- and shikimate-derived rings and subsequent rearrangement to form the xanthone (Diderot et al., 2006).