Polyphenols are a complex family of molecules that contain at least one hydroxy group attached to an aromatic ring. This molecular family can be separated into several distinct classes based on the backbone structure (Fig. ) . Polyphenols are prevalent phytochemicals found in various plants and fungi. They are derived from secondary metabolite pathways which are not yet completely understood. For example, they can derive from the shikimate pathway which involves producing L-phenylalanine, L-tyrosine, and L-tryptophan from the intermediate shikimic acid and these three amino acids are the building blocks for various polyphenols . The production of polyphenols is modulated by both, biotic and abiotic, stress of the plants and fungi, such as herbivores, UV radiation or temperature . Polyphenols are involved in various biological processes, e.g. in plant defense, they exhibit pronounced antioxidant activity and offer protection against UV light in the form of melanin, the result of enzymatic browning .