Figure 3.

Classification of phytochemicals found in botanicals used in cognitive enhancement. For clarity, compounds, which due to the reduced expression were grouped as “others”, are not represented; in a similar fashion, a shortened list of phenolic acids and only the aglycone part of flavonoids are shown. The structural backbone of flavonoids (I) comprises two phenyl rings (A,B) and a heterocyclic ring (C); the flavonoid family is classified into different groups, such as flavonols (II), anthocyanidins (III), flavanols (IV), flavanones (V), flavones (VI), isoflavonoids (VII), and chalcones (VIII), according to the degree of oxidation and substituent chemistry.